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Purpose of Review: The goal of this paper is to aggregate information on monogenic contributions to obesity in the past five years and to provide guidance for genetic testing in clinical care., Recent Findings: Advances in sequencing technologies, increasing awareness, access to testing, and new treatments have increased the utilization of genetics in clinical care. There is increasing recognition of the prevalence of rare genetic obesity from variants with mean allele frequency < 5% -new variants in known genes as well as identification of novel genes- causing monogenic obesity. While most of these genes are in the leptin melanocortin pathway, those in adipocytes may also contribute. Common variants may contribute either to higher lifetime tendency for weight gain or provide protection from monogenic obesity. While specific genetic mutations are rare, these segregate in individuals with early-onset severe obesity; thus, collectively genetic etiologies are not as rare. Some genetic conditions are amenable to targeted treatment. Research into the discovery of novel genetic causes as well as targeted treatment is growing over time. The utility of therapeutic strategies based on the genetic risk of obesity is an advancing frontier., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Since variants of uncertain significance (VUS) reported in genetic testing cannot be acted upon clinically, this classification may delay or prohibit precise diagnosis and genetic counseling in adult genetic disorders patients. Large-scale analyses about qualitatively distinct lines of evidence used for VUS can make them re-classification more accurately. We analyzed 458 Chinese adult patients WES data, within 15 pathogenic evidence PS1, PS2, PM1, PM6 and PP4 were not used for VUS pathogenic classification, meanwhile the PP3, BP4, PP2 were used much more frequently. The PM2&#95;Supporting was used most widely for all reported variants. There were also 31 null variants (nonsense, frameshift, canonical ±1 or 2 splice sites) which were probably the disease-causing variants of the patients were classified as VUS. By analyzed the evidence used for all VUS we recommend that appropriate genetic counseling, reliable releasing of in-house data, allele frequency comparison between case and control, expanded verification in patient family, co-segregation analysis and functional assays were urgent need to gather more evidence to reclassify VUS. We also found adult patients with nervous system disease were reported the most phenotype-associated VUS and the lower the phenotypic specificity, the more reported VUS. This result emphasized the importance of pretest genetic counseling which would make less reporting of VUS. Our result revealed the characteristics of the pathogenic classification evidence used for VUS in adult genetic disorders patients for the first time, recommend a rules-based process to evaluate the pathogenicity of VUS which could provide a strong basis for accurately evaluating the pathogenicity and clinical grade information of VUS. Meanwhile, we further expanded the genetic spectrum and improve the diagnostic rate of adult genetic disorders., (© 2024. The Author(s), under exclusive licence to The Japan Society of Human Genetics.)

Background: The application of massive parallel sequencing technologies in the molecular analysis of Charcot-Marie-Tooth (CMT) has enabled the rapid and cost-effective identification of numerous potentially significant variants for diagnostic purposes. The objective is to reduce the number of variants, focusing only on those with pathogenic significance. The 2015 American College of Medical Genetics and Genomics (ACMG) guidelines aid in achieving this goal, but it is now evident that a pathology or gene-specific review of these rules is essential to avoid misinterpretations that may result from blindly applying the criteria. This study demonstrates how revised ACMG criteria, combined with CMT-specific literature data and expertise, can alter the final classification of a variant., Methods: We reviewed ACMG criteria based on current knowledge of CMT and provided suggestions for adapting them to the specificities of CMT., Results: Of the 226 index patients analysed, a diagnostic yield of 20% was obtained. It is worth noting that the 9% of cases had their final diagnosis changed with the application of the revised criteria, often resulting in the loss of the pathogenic classification of a variant., Conclusions: The widespread availability of high-throughput sequencing technologies has enabled genetic testing even for laboratories without specific disease expertise. Disease-specific ACMG criteria can be a valuable tool to prevent the proliferation of variants of uncertain significance and the misinterpretation of variants., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Aims: Legg-Calve-Perthes disease (LCPD) is a diagnosis of exclusion. Various conditions, such as skeletal dysplasias, can closely mimic LCPD and these must be ruled out to provide appropriate treatment, prognosis, and counseling. Traditionally, genetic testing has not been readily available in pediatric orthopaedic practice. Furthermore, the clinical value of genetic testing patients with LCPD is unclear. With the advance of next-generation sequencing (NGS) technology, genetic testing has become clinically available as a lab test. The purposes of this study were to assess the clinical utility of genetic testing in select patients with LCPD and to determine the patient characteristics of those who tested positive for skeletal dysplasia., Methods: This is an IRB-approved, retrospective study of 63 consecutive patients who presented with Perthes-like symptoms and/or x-ray findings and who had genetic testing. The reason(s) for genetic testing included bilateral hip disease, family history of LCPD, short stature, suspected skeletal dysplasia, atypical radiographic findings, and/or combinations of these reasons., Results: Of the 63 patients, 19 patients (30%) were found to have a pathogenic gene variant. In 8 of the 19, a variety of skeletal dysplasia was diagnosed. The remaining 11 patients were found to be carriers of autosomal recessive disorders. All 19 patients were referred for genetic counseling. Of the 8 patients found to have skeletal dysplasia, 3 had bilateral disease, 3 were <10 percentile in height, 1 had a family history of "LCPD," and 3 had atypical x-ray findings. In addition to the pathogenic variants, numerous genetic variants of unknown significance were found with 2 gene variants showing exactly the same variant found in 2 unrelated patients., Conclusions: With 30% of the patients showing pathogenic results, genetic testing of select patients with Perthes-like disease is valuable in detecting an underlying genetic disorder or a carrier status of a genetic disorder., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

As the adoption and scope of genetic testing continue to expand, interpreting the clinical significance of DNA sequence variants at scale remains a formidable challenge, with a high proportion classified as variants of uncertain significance (VUSs). Genetic testing laboratories have historically relied, in part, on functional data from academic literature to support variant classification. High-throughput functional assays or multiplex assays of variant effect (MAVEs), designed to assess the effects of DNA variants on protein stability and function, represent an important and increasingly available source of evidence for variant classification, but their potential is just beginning to be realized in clinical lab settings. Here, we describe a framework for generating, validating and incorporating data from MAVEs into a semi-quantitative variant classification method applied to clinical genetic testing. Using single-cell gene expression measurements, cellular evidence models were built to assess the effects of DNA variation in 44 genes of clinical interest. This framework was also applied to models for an additional 22 genes with previously published MAVE datasets. In total, modeling data was incorporated from 24 genes into our variant classification method. These data contributed evidence for classifying 4043 observed variants in over 57,000 individuals. Genetic testing laboratories are uniquely positioned to generate, analyze, validate, and incorporate evidence from high-throughput functional data and ultimately enable the use of these data to provide definitive clinical variant classifications for more patients., (© 2024. The Author(s).)

Background: Genetic diagnostics support the diagnosis of hereditary arrhythmogenic diseases, but variants of uncertain significance (VUS) complicate matters, emphasising the need for regular reassessment. Our study aims to reanalyse rare variants in different genes in order to decrease VUS diagnoses and thus improve risk stratification and personalized treatment for patients with arrhythmogenic disorders., Methods: Genomic DNA was analysed using Sanger sequencing and next-generation sequencing (NGS). The Data was evaluated using various databases and in silico prediction tools and classified according to current ACMG standards by two independent experts., Results: We identified 53 VUS in 30 genes, of which 17 variants (32%) were reclassified. 13% each were downgraded to likely benign (LB) and benign (B) and 6% were upgraded to likely pathogenic (LP). Reclassifications mainly occurred among variants initially classified in 2017-2019, with rates ranging from 50 to 60%., Conclusion: The results support the assumption that regular reclassification of VUS is important, as it provides new insights for genetic diagnostics, that benefit patients and guide therapeutic approach., (© 2024. The Author(s).)

Background: Variant classification in the setting of germline genetic testing is necessary for patients and their families to receive proper care. Variants are classified as pathogenic (P), likely pathogenic (LP), uncertain significance (VUS), likely benign (LB) and benign (B) using the standards and guidelines recommended by the American College of Medical Genetics and the Association for Molecular Pathology, with modifications for specific genes. As the literature continues to rapidly expand, and evidence continues to accumulate, prior classifications can be updated accordingly. In this study, we aim to characterise variant reclassifications in Ontario., Methods: DNA samples from patients seen at hereditary cancer clinics in Ontario from January 2012 to April 2022 were submitted for testing. Patients met provincial eligibility criteria for testing for hereditary cancer syndromes or polycystic kidney disease. Reclassification events were determined to be within their broader category of significance (B to LB or vice versa, or P to LP or vice versa) or outside of their broader category as significance (ie, significant reclassifications from B/LB or VUS or P/LP, from P/LP to VUS or B/LB, or from VUS to any other category)., Results: Of the 8075 unique variants included in this study, 23.7% (1912) of variants were reassessed, and 7.2% (578) of variants were reclassified. Of these, 351 (60.7%) variants were reclassified outside of their broader category of significance. Overall, the final classification was significantly different for 336 (58.1%) variants. Importantly, most reclassified variants were downgraded to a more benign classification (n=245; 72.9%). Of note, most reclassified VUS was downgraded to B/LB (n=233; 84.7%)., Conclusions: The likelihood for reclassification of variants on reassessment is high. Most reclassified variants were downgraded to a more benign classification. Our findings highlight the importance of periodic variant reassessment to ensure timely and appropriate care for patients and their families., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Accurate interpretation of sequence variants in inherited retinal dystrophy (IRD) is vital given the significant genetic heterogeneity observed in this disorder. To achieve consistent and accurate diagnoses, establishment of standardized guidelines for variant interpretation is essential. The American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines for variant interpretation serve as the global "cross-disease" standard for classifying variants in Mendelian hereditary disorders. These guidelines propose a systematic approach for categorizing variants into 5 classes based on various types of evidence, such as population data, computational data, functional data, and segregation data. However, for clinical genetic diagnosis and to ensure standardized diagnosis and treatment criteria, additional specifications based on features associated with each disorder are necessary. In this context, we present a comprehensive framework outlining the newly specified ACMG/AMP rules tailored explicitly to IRD in the Japanese population on behalf of the Research Group on Rare and Intractable Diseases (Ministry of Health, Labour and Welfare of Japan). These guidelines consider disease frequencies, allele frequencies, and both the phenotypic and the genotypic characteristics unique to IRD in the Japanese population. Adjustments and modifications have been incorporated to reflect the specific requirements of the population. By incorporating these IRD-specific factors and refining the existing ACMG/AMP guidelines, we aim to enhance the accuracy and consistency of variant interpretation in IRD cases, particularly in the Japanese population. These guidelines serve as a valuable resource for ophthalmologists and clinical geneticists involved in the diagnosis and treatment of IRD, providing them with a standardized framework to assess and classify genetic variants., (© 2024. The Author(s).)

Purpose: Inherited retinal disease (IRD) is a leading cause of blindness. Recent advances in gene-directed therapies highlight the importance of understanding the genetic basis of these disorders. This study details the molecular spectrum in a large United Kingdom (UK) IRD patient cohort., Design: Retrospective study of electronic patient records., Participants: Patients with IRD who attended the Genetics Service at Moorfields Eye Hospital between 2003 and July 2020, in whom a molecular diagnosis was identified., Methods: Genetic testing was undertaken via a combination of single-gene testing, gene panel testing, whole exome sequencing, and more recently, whole genome sequencing. Likely disease-causing variants were identified from entries within the genetics module of the hospital electronic patient record (OpenEyes Electronic Medical Record). Analysis was restricted to only genes listed in the Genomics England PanelApp R32 Retinal Disorders panel (version 3.24), which includes 412 genes associated with IRD. Manual curation ensured consistent variant annotation and included only plausible disease-associated variants., Main Outcome Measures: Detailed analysis was performed for variants in the 5 most frequent genes (ABCA4, USH2A, RPGR, PRPH2, and BEST1), as well as for the most common variants encountered in the IRD study cohort., Results: We identified 4415 individuals from 3953 families with molecularly diagnosed IRD (variants in 166 genes). Of the families, 42.7% had variants in 1 of the 5 most common IRD genes. Complex disease alleles contributed to disease in 16.9% of affected families with ABCA4-associated retinopathy. USH2A exon 13 variants were identified in 43% of affected individuals with USH2A-associated IRD. Of the RPGR variants, 71% were clustered in the ORF15 region. PRPH2 and BEST1 variants were associated with a range of dominant and recessive IRD phenotypes. Of the 20 most prevalent variants identified, 5 were not in the most common genes; these included founder variants in CNGB3, BBS1, TIMP3, EFEMP1, and RP1., Conclusions: We describe the most common pathogenic IRD alleles in a large single-center multiethnic UK cohort and the burden of disease, in terms of families affected, attributable to these variants. Our findings will inform IRD diagnoses in future patients and help delineate the cohort of patients eligible for gene-directed therapies under development., Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article., (Copyright © 2024 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Congenital long QT syndrome (LQTS) is an inherited arrhythmia syndrome associated with sudden cardiac death. Accurate interpretation and classification of genetic variants in LQTS patients are crucial for effective management. All patients with LQTS with a positive genetic test over the past 18 years (2002-2020) in our single tertiary pediatric cardiac center were identified. Reevaluation of the reported variants in LQTS genes was conducted using the American College of Genetics and Genomics (ACMG) guideline after refinement by the US ClinGen SVI working group and guideline by Walsh et al. on genetic variant reclassification, under multidisciplinary input. Among the 59 variants identified. 18 variants (30.5%) were reclassified. A significant larger portion of variants of unknown significance (VUS) were reclassified compared to likely pathogenic (LP)/pathogenic (P) variants (57.7% vs 9.1%, p < 0.001). The rate of reclassification was significantly higher in the limited/disputed evidence group compared to the definite/moderate evidence group (p = 0.0006). All LP/P variants were downgraded in the limited/disputed evidence group (p = 0.0057). VUS upgrades are associated with VUS located in genes within the definite/moderate evidence group (p = 0.0403) and with VUS present in patients exhibiting higher corrected QT intervals (QTc) (p = 0.0445). A significant number of pediatric LQTS variants were reclassified, particularly for VUS. The strength of the gene-disease association of the genes influences the reclassification performance. The study provides important insights and guidance for pediatricians to seek for reclassification of "outdated variants" in order to facilitate contemporary precision medicine., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Genetic testing in the inherited arrhythmia clinic informs risk stratification, clinical management, and family screening. Periodic review of variant classification is recommended as supporting evidence accrues over time. However, there is limited reporting of real-world data on the frequency and impact of variant reclassification., Objective: The purpose of this study was to determine the burden of variant reclassification in our inherited arrhythmia clinic and the impact on clinical management., Methods: Genetic testing reports for patients referred to our clinic from 2004-2020 were reviewed. Reported variants were reinvestigated using ClinVar, VarSome, and a literature review. Classification was updated using the American College of Medical Genetics and Genomics (ACMG) criteria and tested for association with arrhythmic events and modification of medical management., Results: We identified 517 patients (median age 37 years) who underwent gene panel testing. A variant of uncertain significance (VUS) was reported for 94 patients (18.2%) and more commonly identified when using large gene panels (P <.001). A total of 28 of 87 unique VUSs (32.2%) were reclassified to pathogenic/likely pathogenic (n = 11) or benign/likely benign (n = 17). Of 138 originally reported pathogenic variants, 7 (5.1%) lacked support using ACMG criteria. Variant reclassification was not associated with arrhythmic events; however, it did impact genotype-specific counseling and future therapeutic options., Conclusion: In our large real-world patient cohort, we identify a clinically important proportion of both pathogenic variants and VUSs with evidence for reclassification. These findings highlight the need for informed pretest counseling, a regular structured review of variants reported in genetic testing, and the potential benefits to patients for supporting genotype-guided therapy., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Purpose: The Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel (VCEP) was established by the International Society for Gastrointestinal Hereditary Tumours and the Clinical Genome Resource, who set out to develop recommendations for the interpretation of germline APC variants underlying Familial Adenomatous Polyposis, the most frequent hereditary polyposis syndrome., Methods: Through a rigorous process of database analysis, literature review, and expert elicitation, the APC VCEP derived gene-specific modifications to the ACMG/AMP (American College of Medical Genetics and Genomics and Association for Molecular Pathology) variant classification guidelines and validated such criteria through the pilot classification of 58 variants., Results: The APC-specific criteria represented gene- and disease-informed specifications, including a quantitative approach to allele frequency thresholds, a stepwise decision tool for truncating variants, and semiquantitative evaluations of experimental and clinical data. Using the APC-specific criteria, 47% (27/58) of pilot variants were reclassified including 14 previous variants of uncertain significance (VUS)., Conclusion: The APC-specific ACMG/AMP criteria preserved the classification of well-characterized variants on ClinVar while substantially reducing the number of VUS by 56% (14/25). Moving forward, the APC VCEP will continue to interpret prioritized lists of VUS, the results of which will represent the most authoritative variant classification for widespread clinical use., Competing Interests: Conflict of Interest SEP is a member of the scientific advisory panel of Baylor Genetics Laboratories. All other authors declare no conflicts of interest. Ethics Declaration This study was conducted in accordance with the guidelines of the Ethics Committee of the Medical Faculty of the University of Bonn and the 1975 Declaration of Helsinki. Participants of clinical genetic testing gave written informed consent for their data to be used for clinical research and genetic investigations according to local regulations., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: The terminology used for gene-disease curation and variant annotation to describe inheritance, allelic requirement, and both sequence and functional consequences of a variant is currently not standardized. There is considerable discrepancy in the literature and across clinical variant reporting in the derivation and application of terms. Here, we standardize the terminology for the characterization of disease-gene relationships to facilitate harmonized global curation and to support variant classification within the ACMG/AMP framework., Methods: Terminology for inheritance, allelic requirement, and both structural and functional consequences of a variant used by Gene Curation Coalition members and partner organizations was collated and reviewed. Harmonized terminology with definitions and use examples was created, reviewed, and validated., Results: We present a standardized terminology to describe gene-disease relationships, and to support variant annotation. We demonstrate application of the terminology for classification of variation in the ACMG SF 2.0 genes recommended for reporting of secondary findings. Consensus terms were agreed and formalized in both Sequence Ontology (SO) and Human Phenotype Ontology (HPO) ontologies. Gene Curation Coalition member groups intend to use or map to these terms in their respective resources., Conclusion: The terminology standardization presented here will improve harmonization, facilitate the pooling of curation datasets across international curation efforts and, in turn, improve consistency in variant classification and genetic test interpretation., Competing Interests: Conflict of Interest James S. Ware has received research support or consultancy fees from Myokardia, Bristol-Myers Squibb, Pfizer, and Foresite Labs. All other authors declare no conflicts of interest. For the purpose of open access, the authors have applied a CC BY public copyright license to any Author Accepted Manuscript version arising., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Whole genome sequencing (WGS) is becoming the preferred method for molecular genetic diagnosis of rare and unknown diseases and for identification of actionable cancer drivers. Compared to other molecular genetic methods, WGS captures most genomic variation and eliminates the need for sequential genetic testing. Whereas, the laboratory requirements are similar to conventional molecular genetics, the amount of data is large and WGS requires a comprehensive computational and storage infrastructure in order to facilitate data processing within a clinically relevant timeframe. The output of a single WGS analyses is roughly 5 MIO variants and data interpretation involves specialized staff collaborating with the clinical specialists in order to provide standard of care reports. Although the field is continuously refining the standards for variant classification, there are still unresolved issues associated with the clinical application. The review provides an overview of WGS in clinical practice - describing the technology and current applications as well as challenges connected with data processing, interpretation and clinical reporting., (© 2024. The Author(s).)

The ENIGMA research consortium develops and applies methods to determine clinical significance of variants in hereditary breast and ovarian cancer genes. An ENIGMA BRCA1/2 classification sub-group, formed in 2015 as a ClinGen external expert panel, evolved into a ClinGen internal Variant Curation Expert Panel (VCEP) to align with Food and Drug Administration recognized processes for ClinVar contributions. The VCEP reviewed American College of Medical Genetics and Genomics/Association of Molecular Pathology (ACMG/AMP) classification criteria for relevance to interpreting BRCA1 and BRCA2 variants. Statistical methods were used to calibrate evidence strength for different data types. Pilot specifications were tested on 40 variants and documentation revised for clarity and ease of use. The original criterion descriptions for 13 evidence codes were considered non-applicable or overlapping with other criteria. Scenario of use was extended or re-purposed for eight codes. Extensive analysis and/or data review informed specification descriptions and weights for all codes. Specifications were applied to pilot variants with pre-existing ClinVar classification as follows: 13 uncertain significance or conflicting, 14 pathogenic and/or likely pathogenic, and 13 benign and/or likely benign. Review resolved classification for 11/13 uncertain significance or conflicting variants and retained or improved confidence in classification for the remaining variants. Alignment of pre-existing ENIGMA research classification processes with ACMG/AMP classification guidelines highlighted several gaps in the research processes and the baseline ACMG/AMP criteria. Calibration of evidence strength was key to justify utility and strength of different data types for gene-specific application. The gene-specific criteria demonstrated value for improving ACMG/AMP-aligned classification of BRCA1 and BRCA2 variants.

Variants in seven genes (LRRK2, GBA1, PRKN, SNCA, PINK1, PARK7 and VPS35) have been formally adjudicated as causal contributors to Parkinsons disease; however, individuals with Parkinsons disease are often unaware of their genetic status since clinical testing is infrequently offered. As a result, genetic information is not incorporated into clinical care, and variant-targeted precision medicine trials struggle to enrol people with Parkinsons disease. Understanding the yield of genetic testing using an established gene panel in a large, geographically diverse North American population would help patients, clinicians, clinical researchers, laboratories and insurers better understand the importance of genetics in approaching Parkinsons disease. PD GENEration is an ongoing multi-centre, observational study (NCT04057794, NCT04994015) offering genetic testing with results disclosure and genetic counselling to those in the US (including Puerto Rico), Canada and the Dominican Republic, through local clinical sites or remotely through self-enrolment. DNA samples are analysed by next-generation sequencing including deletion/duplication analysis (Fulgent Genetics) with targeted testing of seven major Parkinsons disease-related genes. Variants classified as pathogenic/likely pathogenic/risk variants are disclosed to all tested participants by either neurologists or genetic counsellors. Demographic and clinical features are collected at baseline visits. Between September 2019 and June 2023, the study enrolled 10 510 participants across >85 centres, with 8301 having received results. Participants were: 59% male; 86% White, 2% Asian, 4% Black/African American, 9% Hispanic/Latino; mean age 67.4 ± 10.8 years. Reportable genetic variants were observed in 13% of all participants, including 18% of participants with one or more high risk factors for a genetic aetiology: early onset (

PURPOSE: Clinically ascertained variants are under-utilized in neurodevelopmental disorder research. We established the Brain Gene Registry (BGR) to coregister clinically identified variants in putative brain genes with participant phenotypes. Here, we report 179 genetic variants in the first 179 BGR registrants and analyze the proportion that were novel to ClinVar at the time of entry and those that were absent in other disease databases. METHODS: From 10 academically affiliated institutions, 179 individuals with 179 variants were enrolled into the BGR. Variants were cross-referenced for previous presence in ClinVar and for presence in 6 other genetic databases. RESULTS: Of 179 variants in 76 genes, 76 (42.5%) were novel to ClinVar, and 62 (34.6%) were absent from all databases analyzed. Of the 103 variants present in ClinVar, 37 (35.9%) were uncertain (ClinVar aggregate classification of variant of uncertain significance or conflicting classifications). For 5 variants, the aggregate ClinVar classification was inconsistent with the interpretation from the BGR site-provided classification. CONCLUSION: A significant proportion of clinical variants that are novel or uncertain are not shared, limiting the evidence base for new gene-disease relationships. Registration of paired clinical genetic test results with phenotype has the potential to advance knowledge of the relationships between genes and neurodevelopmental disorders.

BackgroundMethodsResultsConclusionDanon disease is a rare, multisystemic X-linked dominant disorder caused by variants in the LAMP2 gene. It can be associated with retinal degeneration, but this is not well characterized. Here we describe a late presentation of a mild retinal phenotype, initially diagnosed as choroideremia carrier, associated with a novel variant in the LAMP2 gene.Retrospective analysis of the case included medical history, ophthalmic examination, multimodal retinal imaging, and microperimetry. Genetic testing was conducted to establish the molecular diagnosis.A 54-year-old female presented with worsening night vision, without any family history. BCVA was 6/6 bilaterally and fundus examination showed light peripheral pigmentary changes bilaterally. FAF demonstrated a widespread speckled pattern and OCT revealed hyper-reflective spots in the outer nuclear layer. Differentials included non-genetic and genetic causes, suspected of being a manifesting choroideremia carrier. However, initial genetic testing by targeted analysis of retinal disorders did not detect a pathogenic variant. Further systems review revealed that the patient had previously been diagnosed with dilated cardiomyopathy, mini-stroke and partial deafness. Subsequent whole mitochondrial genome sequencing analysis did not detect any pathogenic variants too. Finally, whole exome sequencing with targeted analysis of a panel of hypertrophic cardiomyopathy genes identified a novel pathogenic heterozygous variant (c.925del, p.(Ser309fs)) in the LAMP2 gene, confirming the diagnosis of X-linked Danon disease.Recording previous medical history and extraocular symptoms is crucial. The similarity in choroideremia carrier and Danon disease retinal phenotypes suggests a possible common pathway in these two genes where pathogenic variants lead to retinal pigment epithelium degeneration. [ABSTRACT FROM AUTHOR]

Cystinosis is a rare lysosomal storage disorder caused by a variant in the CTNS gene that leads to the accumulation of cystine in the body's tissues. It has been classified into three subtypes based on its clinical presentation: severe infantile nephropathic cystinosis, intermediate mild form, and ocular non-nephropathic adult form. We report a teenage girl who presented with end stage kidney disease as her first presentation and was found to have corneal cystine crystals upon ophthalmic evaluation. Genetic testing confirmed that she has a CTNS variant, a CTNS variant c.520A > C p.(Ser174Arg) never described in the literature previously. Full family genetic screening supported the diagnosis. She was started on oral and ocular cysteamine and maintained on peritoneal dialysis for a few months and eventually underwent a successful deceased donor kidney transplantation. These findings expand the spectrum of CTNS gene variants and highlight the potential of atypical and severe presentations of this variant during adolescence. [ABSTRACT FROM AUTHOR]

Truncating genetic variants of SORL1, encoding the endosome recycling receptor SORLA, have been accepted as causal of Alzheimer's disease (AD). However, most genetic variants observed in SORL1 are missense variants, for which it is complicated to determine the pathogenicity level because carriers come from pedigrees too small to be informative for penetrance estimations. Here, we describe three unrelated families in which the SORL1 coding missense variant rs772677709, that leads to a p.Y1816C substitution, segregates with Alzheimer's disease. Further, we investigate the effect of SORLA p.Y1816C on receptor maturation, cellular localization, and trafficking in cell-based assays. Under physiological circumstances, SORLA dimerizes within the endosome, allowing retromer-dependent trafficking from the endosome to the cell surface, where the luminal part is shed into the extracellular space (sSORLA). Our results showed that the p.Y1816C mutant impairs SORLA homodimerization in the endosome, leading to decreased trafficking to the cell surface and less sSORLA shedding. These trafficking defects of the mutant receptor can be rescued by the expression of the SORLA 3Fn-minireceptor. Finally, we find that iPSC-derived neurons with the engineered p.Y1816C mutation have enlarged endosomes, a defining cytopathology of AD. Our studies provide genetic as well as functional evidence that the SORL1 p.Y1816C variant is causal for AD. The partial penetrance of the mutation suggests this mutation should be considered in clinical genetic screening of multiplex early-onset AD families. [ABSTRACT FROM AUTHOR]

Porphyria is a group of rare metabolic disorders caused by mutations in the genes encoding crucial enzymes in the heme biosynthetic pathway. However, the lack of comprehensive genetic analysis of porphyria patients in the Chinese population makes identifying and diagnosing carriers of the condition challenging. Using the ChinaMAP database, we determined the frequencies of P/LP porphyria-associated gene variants according to the ACMG guidelines. We also calculated the carrier rates and prevalence of each type of porphyria in the Chinese population under Hardy–Weinberg equilibrium. Compared with the variants in the gnomAD database, the genetic spectrum of porphyria-related P/LP variants in the Chinese population is distinct. In the ChinaMAP database, we identified 23 variants. We estimated the carrier rates for autosomal dominant porphyrias (AIP, HCP, VP, PCT) in the Chinese population to be 1/1059, 1/1513, 1/10588, and 1/1765, respectively. For autosomal recessive porphyrias (ADP, EPP, HEP, CEP), the estimated carrier rates were 1/5294, 1/2117, 1/1765, and 1/2647, respectively, with predicted prevalence rates of 8.92 × 10−9, 7.51 × 10−5, 8.02 × 10−8, and 3.57 × 10−8, respectively. Notably, 12 of the variants we identified were unique to the Chinese population. The predicted prevalence rate of EPP was the highest among the various types of porphyria in the Chinese population, while the others were moderate to low. This is the first comprehensive genetic study on porphyria in the Chinese population. Clarifying the genetic characteristics of various porphyria types among the Chinese population provides scientifically sound reference data for both research and genetic screening to identify porphyria carriers. [ABSTRACT FROM AUTHOR]

Background: Accumulating evidence has suggested that sleep disturbances and disorders are common in patients who undergo knee arthroplasty. Revision surgery represents one of the most catastrophic outcomes of knee arthroplasty. However, it remains unclear whether sleep traits are the causes or consequences of knee arthroplasty revision. This study aimed to genetically examine the relationships between sleep traits and knee arthroplasty revision. Methods: To determine the causal relationship between sleep traits and knee arthroplasty revision, we employed two-sample Mendelian randomization (MR) using summary statistics from the largest publicly available genome-wide association studies (GWASs). The MR design uses genetic variants as instrumental variables to help separate causal relationships from non-causal associations. The main analyses included an inverse variance weighted (IVW) meta-analysis to obtain primary effect estimates. Sensitivity analyses involving the weighted median approach and MR-Egger regression were also conducted to check for potential pleiotropic biases. Numerous complementary sensitivity analyses were also performed to identify statistically significant causal correlations when there were horizontal pleiotropy and heterogeneity across variants. Finally, a reverse MR analysis was performed to evaluate the possibility of reverse causation. Results: In the absence of heterogeneity and horizontal pleiotropy, the IVW method revealed that genetically-predicted short sleep duration short sleep duration (average sleep duration of 24 h is 6 h or less) was positively correlated with the risk of knee arthroplasty revision (odds ratio = 1.03, 95% confidence interval = 1.01–1.05, and P = 0.003), while the association between genetically-predicted long sleep duration and knee arthroplasty was negative. The reverse MR analysis did not yield evidence supporting reverse causality relation between knee arthroplasty revision and sleep phenotypes. Conclusion: This research indicated that, of the 10 sleep phenotypes we analyzed, only sleep duration was causally associated with knee arthroplasty revision. These discoveries added to the understanding of the role of sleep traits in the etiology of knee arthroplasty revision, which might further expand our insights into the prevention of knee arthroplasty revision. Highlights: 1. Genetically-predicted short sleep duration increases risk of knee arthroplasty revision. 2. Mendelian randomization used to analyze sleep traits and knee revision relationship. 3. Sleep duration causally linked to lower risk of knee arthroplasty revision. 4. No evidence found for reverse causality between knee revision and sleep traits. 5. Study enhances understanding of sleep's role in knee arthroplasty outcomes. [ABSTRACT FROM AUTHOR]

AbstractObjective: To report the frequency of pathogenic SOD1 gene variants in a screening program in amyotrophic lateral sclerosis (ALS), and the clinical practice of transition to an expanded access program (EAP) of tofersen treatment. Methods: From October 2021 to February 2024, at 11 ALS centers in Germany genetic testing for SOD1, FUS, TARDBP, and C9orf72 was performed. Patients were offered to opt for notification either about all genetic variants or SOD1 variants relevant for tofersen therapy. The transition to the EAP with tofersen was assessed. Results: 1935 patients were screened (94.7% sporadic ALS). 48.8% (n = 928) opted for notification of treatment-relevant information. Genetic variants were found as follows: SOD1 (likely) pathogenic variants (class 4/5) 1.8% (n = 34), variants of unknown significance (class 3) 0.8% (n = 16), FUS (class 4/5) 0.9% (n = 17), TARDBP (class 4/5) 1.3% (n = 25), C9orf72 hexanucleotide repeat expansion 7.0% (n = 135). In SOD1-ALS (encompassing class 3–5 variants, n = 50), 68.0% (n = 34) reported a negative family history. 74.0% (n = 37) of SOD1-ALS patients – which represent 1.9% of all participants of the screening program – were transitioned to tofersen. Median duration from start of genetic testing to treatment was 94 days (57 to 295 days). Eight patients declined treatment whereas five individuals died before initiation of therapy. Conclusion: The finding of SOD1 variants in patients with a negative family history underscores the need for a broad genetic screening in ALS. In SOD1-ALS, the treatment option with tofersen was mostly utilized. The wide range in the transition time to tofersen calls for a SOD1-ALS management program. [ABSTRACT FROM AUTHOR]

Background: Wilson disease (WD) is an autosomal recessive inherited disease caused by ATP7B variants and characterized by copper metabolism defects. However, children with WD are often asymptomatic, making the clinical diagnosis difficult. Therefore, more accurate methods are required for clinical diagnosis. The objective of this study was to highlight the phenotypic and genetic characteristics of children with WD in northeast China. Methods: We retrospectively analyzed the clinical data and gene sequencing results of 65 children with WD from January 1, 2014, to December 31, 2022, at the Shengjing Hospital of China Medical University. All data refer to the time of diagnosis before treatment. Results: The median age at diagnosis was 5 years (range 1.2–15 years). In 50 cases (50/65, 76.9%) patients, routine physical examinations revealed only abnormal liver function. However, they had a significantly negative (p < 0.05) Kayser–Fleischer ring (KF). Children with acute liver failure had significantly increased 24 h urinary copper excretion (p < 0.05). We detected 46 genetic variants of ATP7B, including seven novel variants. The most frequent variant was p.R778L with an allele frequency of 38.7%. Phenotype-genotype correlation analysis suggested that p.R778L was significantly associated with lower serum ceruloplasmin levels and higher zinc levels (p < 0.05). The loss-of-function (LOF) variant was associated with significantly lower albumin levels (p < 0.05). Conclusion: Most children with WD are asymptomatic, which makes early diagnosis of WD difficult. Therefore, clinical and laboratory characteristics as well as genetic testing are essential. p.R778L is the most frequent variant of ATP7B in China and may play an important role in lowering serum ceruloplasmin levels. [ABSTRACT FROM AUTHOR]

Background: Feed efficiency is a crucial economic trait in poultry industry. Both host genetics and gut microbiota influence feed efficiency. However, the associations between gut microbiota and host genetics, as well as their combined contributions to feed efficiency in laying hens during the late laying period, remain largely unclear. Methods: In total, 686 laying hens were used for whole-genome resequencing and liver transcriptome sequencing. 16S rRNA gene sequencing was conducted on gut chyme (duodenum, jejunum, ileum, and cecum) and fecal samples from 705 individuals. Bioinformatic analysis was performed by integrating the genome, transcriptome, and microbiome to screen for key genetic variations, genes, and gut microbiota associated with feed efficiency. Results: The heritability of feed conversion ratio (FCR) and residual feed intake (RFI) was determined to be 0.28 and 0.48, respectively. The ileal and fecal microbiota accounted for 15% and 10% of the FCR variance, while the jejunal, cecal, and fecal microbiota accounted for 20%, 11%, and 10% of the RFI variance. Through SMR analysis based on summary data from liver eQTL mapping and GWAS, we further identified four protein-coding genes, SUCLA2, TNFSF13B, SERTM1, and MARVELD3, that influence feed efficiency in laying hens. The SUCLA2 and TNFSF13B genes were significantly associated with SNP 1:25664581 and SNP rs312433097, respectively. SERTM1 showed significant associations with rs730958360 and 1:33542680 and is a potential causal gene associated with the abundance of Corynebacteriaceae in feces. MARVELD3 was significantly associated with the 1:135348198 and was significantly correlated with the abundance of Enterococcus in ileum. Specifically, a lower abundance of Enterococcus in ileum and a higher abundance of Corynebacteriaceae in feces were associated with better feed efficiency. Conclusions: This study confirms that both host genetics and gut microbiota can drive variations in feed efficiency. A small portion of the gut microbiota often interacts with host genes, collectively enhancing feed efficiency. Therefore, targeting both the gut microbiota and host genetic variation by supporting more efficient taxa and selective breeding could improve feed efficiency in laying hens during the late laying period. [ABSTRACT FROM AUTHOR]

Genome analysis of individuals affected by retinitis pigmentosa (RP) identified two rare nucleotide substitutions at the same genomic location on chromosome 11 (g.61392563 [GRCh38]), 69 base pairs upstream of the start codon of the ciliopathy gene TMEM216 (c.−69G>A, c.−69G>T [GenBank: NM_001173991.3]), in individuals of South Asian and African ancestry, respectively. Genotypes included 71 homozygotes and 3 mixed heterozygotes in trans with a predicted loss-of-function allele. Haplotype analysis showed single-nucleotide variants (SNVs) common across families, suggesting ancestral alleles within the two distinct ethnic populations. Clinical phenotype analysis of 62 available individuals from 49 families indicated a similar clinical presentation with night blindness in the first decade and progressive peripheral field loss thereafter. No evident systemic ciliopathy features were noted. Functional characterization of these variants by luciferase reporter gene assay showed reduced promotor activity. Nanopore sequencing confirmed the lower transcription of the TMEM216 c.−69G>T allele in blood-derived RNA from a heterozygous carrier, and reduced expression was further recapitulated by qPCR, using both leukocytes-derived RNA of c.−69G>T homozygotes and total RNA from genome-edited hTERT-RPE1 cells carrying homozygous TMEM216 c.−69G>A. In conclusion, these variants explain a significant proportion of unsolved cases, specifically in individuals of African ancestry, suggesting that reduced TMEM216 expression might lead to abnormal ciliogenesis and photoreceptor degeneration. [Display omitted] Genetic analyses of retinitis pigmentosa (RP)-affected individuals in African and Pakistani populations, along with functional validations, identified two novel pathogenic substitutions in the UTR of TMEM216 : c.−69G>T and c.−69G>A. The c.−69G>T variant is estimated to account for about 20% of RP cases in individuals of African ancestry, including African Americans. [ABSTRACT FROM AUTHOR]

Background: Complement activation in atypical hemolytic uremic syndrome (aHUS), C3 glomerulonephropathy (C3G) and immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) may be associated with rare genetic variants. Here we describe gene variants in the Swedish and Norwegian populations. Methods: Patients with these diagnoses (N=141) were referred for genetic screening. Sanger or next-generation sequencing were performed to identify genetic variants in 16 genes associated with these conditions. Nonsynonymous genetic variants are described when they have a minor allele frequency of <1% or were previously reported as being disease-associated. Results: In patients with aHUS (n=94, one also had IC-MPGN) 68 different genetic variants or deletions were identified in 60 patients, of which 18 were novel. Thirty-two patients had more than one genetic variant. In patients with C3G (n=40) 29 genetic variants, deletions or duplications were identified in 15 patients, of which 9 were novel. Eight patients had more than one variant. In patients with IC-MPGN (n=7) five genetic variants were identified in five patients. Factor H variants were the most frequent in aHUS and C3 variants in C3G. Seventeen variants occurred in more than one condition. Conclusion: Genetic screening of patients with aHUS, C3G and IC-MPGN is of paramount importance for diagnostics and treatment. In this study, we describe genetic assessment of Nordic patients in which 26 novel variants were found. [ABSTRACT FROM AUTHOR]

The Kerey is one of the prominent Kazakh tribes and has long been a subject of ethnographic scrutiny, with a lack of consensus on its origin and traditional genealogy. Their historical significance, intertwined with the emergence of the empire established by Genghis Khan, necessitates a comprehensive understanding of their genetic history. This study focuses on unraveling the genetic heritage of the Kerey tribe. We conducted a comprehensive analysis of Y-chromosome data from genetic genealogy as citizen science and genetic screening of 23 Y-STRs and 37 Y-SNPs on 207 males from the Kerey tribe within academic science. Our results reveal two prevalent phylogenetic lineages within the C2a1a3a-F3796 haplogroup, also known as the C2*-Star Cluster (C2*-ST), which is one of the founding paternal lineages of the ancient Niru'un clan of the Mongols: C2-FT411734 and C2-FT224144, corresponding to the Abak and Ashamaily clans. While indicating a common male ancestry for them, our findings challenge the notion that they are full siblings. Additionally, genetic diversity analysis of the Y-chromosomes in the Kerey tribe and Kazakhs confirms their kinship with the Uissun tribe but refutes the claim of the Abak clan's progenitor originating from this tribe. Furthermore, genetic evidence fails to support popular historical and ethnographic hypotheses regarding the Kerey tribe's kinship with the Uak, Sirgeli, Adai, Törtkara, Karakerey, and Kereyit Kazakh tribes. The absence of a genetic paternal connection with the Kereyt tribe raises doubts about the genealogical link between the Kerey tribe and the stepfather of Genghis Khan. [ABSTRACT FROM AUTHOR]

High-throughput sequencing technologies have increasingly led to discovery of disease-causing genetic variants, primarily in postnatal multi-cell DNA samples. However, applying these technologies to preimplantation genetic testing (PGT) in nuclear or mitochondrial DNA from single or few-cells biopsied from in vitro fertilised (IVF) embryos is challenging. PGT aims to select IVF embryos without genetic abnormalities. Although genotyping-by-sequencing (GBS)-based haplotyping methods enabled PGT for monogenic disorders (PGT-M), structural rearrangements (PGT-SR), and aneuploidies (PGT-A), they are labour intensive, only partially cover the genome and are troublesome for difficult loci and consanguineous couples. Here, we devise a simple, scalable and universal whole genome sequencing haplarithmisis-based approach enabling all forms of PGT in a single assay. In a comparison to state-of-the-art GBS-based PGT for nuclear DNA, shallow sequencing-based PGT, and PCR-based PGT for mitochondrial DNA, our approach alleviates technical limitations by decreasing whole genome amplification artifacts by 68.4%, increasing breadth of coverage by at least 4-fold, and reducing wet-lab turn-around-time by ~2.5-fold. Importantly, this method enables trio-based PGT-A for aneuploidy origin, an approach we coin PGT-AO, detects translocation breakpoints, and nuclear and mitochondrial single nucleotide variants and indels in base-resolution. This work demonstrates a novel preimplantation genetic testing (PGT) method that detects aberrations in both the nuclear and mitochondrial genomes of IVF embryos. The technology traces the origin of chromosomal aberrations to before or after fertilisation. [ABSTRACT FROM AUTHOR]

Cleft lip and/or palate (CL/P) are the most common congenital anomalies in the craniofacial region, leading to morphological and functional disruptions in the facial region. Their etiology involves genetic and environmental factors, with genetics playing a crucial role. This study aimed to investigate the association of four single nucleotide polymorphisms (SNPs)—rs987525, rs590223, rs522616, and rs4714384—with CL/P in the Polish population. We analyzed DNA samples from 209 individuals with CL/P and 418 healthy controls. The impact of SNPs on the presence of CL/P was assessed using multivariate logistic regression. Significant associations were found with rs987525. Specifically, the AC genotype was linked to an increased CL/P risk (odds ratio [OR] = 1.95, 95% confidence interval [CI]: 1.34–2.83, p < 0.001), while the CC genotype was associated with a decreased risk (OR = 0.46, 95% CI: 0.32–0.67, p < 0.001). Rs4714384 was also significant, with the CT genotype correlated with a reduced risk of CL/P (OR = 0.66, 95% CI: 0.46–0.94, p = 0.011). SNPs rs590223 and rs522616 did not show statistically significant associations. These results underscore the role of rs987525 and rs4714384 in influencing CL/P risk and suggest the utility of genetic screening in understanding CL/P etiology. [ABSTRACT FROM AUTHOR]

Background/Objective: To investigate the prevalence and effects of genetic variants (GVs) in survivors of thoracic aortic dissection/aneurysm repair. Methods: Patients aged 18–80 years who survived follow-up after cardiosurgical or endovascular repair of thoracic aortic aneurysm or dissection at a single tertiary center between 2008 and 2019 and underwent genetic testing were enrolled. The exclusion criteria were age >60 years, no offspring, and inflammatory- or trauma-related pathogenesis. Follow-up entailed computed tomography-angiography at 3 and 9 months and annually thereafter. All patients underwent genetic analyses of nine genes using next-generation sequencing. In cases of specific suspicion, the analysis was expanded to include 32 genes. Results: The study included 95 patients. The follow-up period was 3 ± 2.5 years. GVs were detected in 40% of patients. Correlation analysis according to primary diagnosis showed no significant correlation in disease persistence, progression, or in reintervention rates in aneurysm patients and a correlation of disease persistence with genetic variants according to variant class in dissection patients (p = 0.037). Correlation analysis according to follow-up CD finding revealed that patients with detected dissection, irrespective of original pathology, showed a strong correlation with genetic variants regarding disease progression and reintervention rates (p = 0.012 and p = 0.047, respectively). Conclusions: The prevalence of VUS is high in patients with aortic pathology. In patients with dissected aorta in the follow-up, irrespective of original pathology, genetic variants correlate with higher reintervention rates, warranting extended-spectrum genetic testing. The role of VUS may be greater than is currently known. [ABSTRACT FROM AUTHOR]

Simple Summary: Studies of genetic predisposition to renal cell carcinoma (RCC) have been highly variable in design and have reported similarly highly variable rates of cases identified as carrying pathogenic variants in cancer susceptibility genes (4–26%). The aim of our study was to conduct a population-based study of genetic predisposition to RCC. We conducted a 21-gene panel sequencing study and identified that 18/1029 participants (1.7%) carried a pathogenic or likely pathogenic (PLP) variant. Genes with PLP variants included BAP1, FH, FLCN, MITF, MSH6, SDHB, TSC1, and VHL. This study provides further evidence that family history alone may not be sufficient for identifying all individuals who are at increased genetic risk of renal cell carcinoma, and further research is urgently needed to understand how to target genetic testing to identify those at high genetic risk of kidney cancer. Renal cell carcinoma (RCC) has been associated with germline pathogenic or likely pathogenic (PLP) variants in recognised cancer susceptibility genes. Studies of RCC using gene panel sequencing have been highly variable in terms of study design, genes included, and reported prevalence of PLP variant carriers (4–26%). Studies that restricted their analysis to established RCC predisposition genes identified variants in 1–6% of cases. This work assessed the prevalence of clinically actionable PLP variants in renal cancer predisposition genes in an Australian population-based sample of RCC cases. Germline DNA from 1029 individuals diagnosed with RCC who were recruited through the Victoria and Queensland cancer registries were screened using a custom amplicon-based panel of 21 genes. Mean age at cancer diagnosis was 60 ± 10 years, and two-thirds (690, 67%) of the participants were men. Eighteen participants (1.7%) were found to carry a PLP variant. Genes with PLP variants included BAP1, FH, FLCN, MITF, MSH6, SDHB, TSC1, and VHL. Most carriers of PLP variants did not report a family history of the disease. Further exploration of the clinical utility of gene panel susceptibility testing for all RCCs is warranted. [ABSTRACT FROM AUTHOR]

This study explores the association of vitamin D-binding protein (VDBP) gene polymorphisms, vitamin D levels, and the severity of COVID-19, including the need for intensive care unit (ICU) hospitalization. We analyzed a cohort of 56 consecutive age- and gender-matched adult COVID-19-positive patients and categorized them into three groups: outpatients with mild illness, inpatients with moderate disease, and ICU patients. We measured levels of free, total, and bioavailable 25-hydroxyvitamin D [25(OH)D], VDBP, and albumin. VDBP polymorphisms rs5488 and rs7041 were identified using real-time PCR. A significant proportion of ICU patients were vitamin D-deficient (56.25%) compared to outpatients (10%) and inpatients (5%) (p = 0.0003). ICU patients also had notably lower levels of VDBP (median: 222 mg/L) and total 25(OH)D (median: 18.8 ng/mL). Most patients carried heterozygous rs7041 (60.7%) and wild-type rs4588 (58.9%) genotypes. The distribution of rs7041 SNP varied significantly among groups (p = 0.0301), while rs4588 SNP distribution did not (p = 0.424). Heterozygous rs4588 patients had significantly lower VDBP levels (p = 0.029) and reduced bioavailable 25(OH)D compared to those with wild-type rs4588 (p = 0.020). Our findings indicate that VDBP gene polymorphisms, particularly rs7041 and rs4588, are associated with vitamin D status and the severity of COVID-19. The lower VDBP levels and bioavailable vitamin D in ICU patients suggest that these genetic variants may influence disease severity and hospitalization needs. These results highlight the potential role of VDBP polymorphisms in COVID-19 severity, suggesting that genetic screening could be valuable in assessing the risk of severe outcomes and guiding personalized treatment strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: Germline mutation rates and spectra across three cohorts of Chinese patients: a high-risk breast cancer cohort, an unselected breast cancer cohort, and a benign breast lesion cohort were compared. The high-risk cohort had the highest mutation rate at 11.9%, while the unselected cancer and benign lesion cohorts had rates of 6.5% and 8.1%, respectively. Notably, 29.3% of the unselected breast cancer patients met genetic testing criteria, and this subgroup had a mutation rate similar to the high-risk cohort. High-penetrance gene mutations were only found in the high-risk and unselected cancer cohorts. Unexpectedly, a 2% mutation rate was observed in the benign lesion cohort. These findings highlight the need for broader genetic testing of all breast cancer patients, not just those deemed high-risk, to identify more individuals harboring clinically relevant germline mutations. Mutation study for high-risk breast and ovarian cancer (HBOC) has been extensively studied in patients of different ethnicities. Here we compared the germline mutation rate and mutation spectrum of patients (n = 4341) with benign breast diseases or breast cancers, with and without other risk factors. Three cohorts of Chinese patients were recruited. The first cohort, high-risk cohort (HR, n = 3935) included high-risk breast cancer patients fulfilling high-risk HBOC criteria and who are recruited at our genetics clinic. The second cohort, unselected cancer cohort (CC, n = 307) was from general recruitment of patients with breast cancer at breast surgery clinics. The third cohort, benign breast lesion cohort (NC, n = 99) comprised 99 patients with benign breast diseases such as fibroadenoma, fibroadenomatoid hyperplasia, and intraductal papilloma. Thirty HBOC related genes were sequenced on the above-mentioned patient cohorts. The germline mutation rates of HR, CC, and NC cohort were 11.9%, 6.5%, and 8.1%, respectively. In the CC cohort, 29.3% (90/307) of patients fulfilled the National Comprehensive Cancer Network (NCCN) high-risk genetic test criteria 2022 v.2. The mutation rate for this group of patients was 11.1%, similar to that of the HR cohort, while the mutation rate for those not fulfilling testing criteria was 4.6%, like that of the NC cohort. High penetrance genes (BRCA1/2, CDH1, PALB2, PTEN, and TP53) mutations were only found in the HR (10.6%) and CC (3.3%) cohorts but were not found in the NC cohort. ATM, BRIP1, RAD51C, and RAD51D mutations were identified in all cohorts. RAD51C and RAD51D mutations showed conflicting penetrance. An unexpectedly high mutation rate of total 2% was found in the NC cohort but it was only 0.3% and 0.5% in the HR cohort and CC cohort, respectively. Our results show a clinical need to enhance genetic testing of unselected breast cancer patients to identify the high-risk patients. [ABSTRACT FROM AUTHOR]

Objective: Maturity onset diabetes of the young (MODY) occurs due to mutations in genes involved in pancreatic beta cell function and insulin secretion, has heterogeneous clinical and laboratory features, and account for 1-5% of all diabetes cases. The prevalence and distribution of MODY subtypes vary between countries. The aim of this study was to evaluate the clinical and laboratory characteristics, mutation distribution, and phenotype-genotype relationship in a large case series of pediatric Turkish patients genetically diagnosed with MODY. Methods: MODY cases from 14 different pediatric endocrinology departments were included. Diagnosis, treatment, follow-up data, and results of genetic analysis were evaluated. Results: A total of 224 patients were included, of whom 101 (45%) were female, and the mean age at diagnosis was 9.4±4.1 years. Gene variant distribution was: 146 (65%) GCK; 43 (19%) HNF1A; 8 (3.6%) HNF4A, 8 (3.6%) KLF11 and 7 (3.1%) HNF1B. The remaining 12 variants were: PDX (n=1), NEUROD1 (n=3), CEL (n=1), INS (n=3), ABCC8 (n= 3) and KJNC11 (n=1). Of the cases, 197 (87.9%) were diagnosed with incidental hyperglycemia, 16 with ketosis (7%) and 7 (3%) with diabetic ketoacidosis (DKA), while 30% presented with classical symptoms of diabetes. Two-hundred (89%) had a family history of diabetes. Anti-GAD antibody was detected in 13 cases, anti-islet antibody in eight and anti-insulin antibody in four. Obesity was present in 16. Distribution of therapy was: 158 (71%) diet only; 23 (11%) intensive insulin treatment; 17 (7.6%) sulfonylureas; 10 (4.5%) metformin; and 6 (2.7%) insulin and oral anti-diabetic treatment. Conclusion: This was the largest genetically diagnosed series from Turkey. The most common gene variants were GCK and HNF1A with much lower proportions for other MODY types. Hyperglycemia was the most common presenting symptom while 11% of patients had diabetes-associated autoantibodies and 7% were obese. The majority of patients received dietary management only. [ABSTRACT FROM AUTHOR]

Background & Objective: Hypovitaminosis D has shown to be linked with T2DM development and control in numerous studies. The association of SNPs in genes related to VitD metabolism with T2DM has not been sufficiently studied. Consequently, our aim in the present study was to explore the association between genetic variants in genes connected with VitD, mainly a SNP in GC (rs1155563), a SNP in DHCR7 (rs12785878) and a SNP in CYP2R1 (rs10500804) with glycaemic parameters in females with T2DM in Saudi Arabia. Methods: The cross-sectional study included 149 females (age 38-52 years) with T2DM from Jeddah, Saudi Arabia (September 2022-March 2023). Blood was extracted from the participants for biochemical tests including measuring VitD [25(OH)D] concentration, parameters of glycaemia (HbA1c, insulin, fasting glucose and insulin sensitivity indices including HOMA2-IR and HOMA2-%β), and for genomic DNA isolation. Sanger DNA sequencing was used to screen for VitD genetic polymorphisms (rs1155563, rs12785878 and rs10500804). Results: Minor allele frequency for rs1155563C, rs12785878T and rs10500804G was 0.21, 0.23 and 0.37, respectively. Levels of 25(OH)D and glycaemic parameters as well did not show any significant difference between the genotypes of each SNP. Conclusion: This study showed lack of association of rs1155563 in GC, rs12785878 in DHCR7 and rs10500804 in CYP2R1 with VitD level primarily and with glycaemic parameters secondarily. Additional research is required to explore further other VitD genetic polymorphisms influencing T2DM which might lead consequently to genetically-based personalized management for T2DM. [ABSTRACT FROM AUTHOR]

The CSF1R gene, located on chromosome 5, encodes a 108 kDa protein and plays a critical role in regulating myeloid cell function. Mutations in CSF1R have been identified as a cause of a rare white matter disease called adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP, also known as CSF1R-related leukoencephalopathy), characterized by progressive neurological dysfunction. This study aimed to broaden the genetic basis of ALSP by identifying novel CSF1R variants in patients with characteristic clinical and imaging features of ALSP. Genetic analysis was performed through whole-exome sequencing or panel analysis for leukodystrophy genes. Variant annotation and classification were conducted using computational tools, and the identified variants were categorized following the recommendations of the American College of Medical Genetics and Genomics (ACMG). To assess the evolutionary conservation of the novel variants within the CSF1R protein, amino acid sequences were compared across different species. The study identified six previously unreported CSF1R variants (c.2384G>T, c.2133_2919del, c.1837G>A, c.2304C>A, c.2517G>T, c.2642C>T) in seven patients with ALSP, contributing to the expanding knowledge of the genetic diversity underlying this rare disease. The analysis revealed considerable genetic and clinical heterogeneity among these patients. The findings emphasize the need for a comprehensive understanding of the genetic basis of rare diseases like ALSP and underscored the importance of genetic testing, even in cases with no family history of the disease. The study's contribution to the growing spectrum of ALSP genetics and phenotypes enhances our knowledge of this condition, which can be crucial for both diagnosis and potential future treatments. [ABSTRACT FROM AUTHOR]

Familial Mediterranean fever (FMF) is an autoinflammatory disease characterized by recurrent attacks of fever, serositis (peritonitis, pleuritis, or synovitis), and erysipelas‐like erythema. Genetic variants in the MEFV gene are associated with this disease. Familial Mediterranean fever is considered an autosomal recessive disease. However, in Middle Eastern countries, a third of the patients expressing FMF manifestations, carry a single mutation only. Moreover, some cases of pure dominant inheritance linked to specific single MEFV variants have also been described. This complex inheritance of MEFV‐associated inflammatory diseases poses a serious challenge when interpreting the results of genetic testing in patients having recurrent fever syndromes. In addition, in certain situations, asymptomatic individuals may be incidentally found to carry MEFV variants. These cases pose the question of their exact diagnosis and whether they should be treated. Previous studies have focused on genetic results interpretations among symptomatic patients. In the current article, we would like to elaborate on the genetic interpretation in cases of symptomatic individuals suspected to have FMF and on asymptomatic individuals carrying MEFV variants. We aim to assist physicians unfamiliar with FMF to cope with genetic results interpretation when facing symptomatic and asymptomatic individuals carrying MEFV variants and suggest a management plan accordingly. [ABSTRACT FROM AUTHOR]

Plain language summary: Expanded carrier screening (ECS) is a genetic screening test carried out by analysing a blood sample. This screen can be used to detect whether the individual unknowingly carries gene variants associated with common genetic conditions, such as cystic fibrosis, that may be passed on to their children. It is typically performed in reproductive medicine for those who are considering having a family either naturally or via fertility treatment. Many donor sperm and egg banks, particularly in the USA and Europe, also perform blanket ECS testing on all their prospective sperm and egg donors. ECS is not currently routine practice in the UK, but a growing number of patients are requesting it before treatment. All of us carry gene variants of some sort that may cause autosomal recessive disease in their children if their partner or donor also carry a variant in the same gene. An autosomal recessive disease means two copies of an abnormal gene must be present in order for the disease or trait (such as cystic fibrosis or sickle cell disease) to develop. One copy of the variant means the person is a carrier but does not have the condition. Two copies, i.e. from the mother and father, means the child has a 25% chance of having the genetic disease. Carrying a gene variant does not mean that the individual would necessarily have any symptoms of the disease or any features of the condition. Genetic tests for specific conditions are currently available either before or during pregnancy for prospective parents who have a family or personal history of a genetic condition, or for those from ethnic backgrounds where certain conditions – such as haemoglobinopathies (blood disorders) – are common, prompting referral to a clinical genetics department. Expanded carrier screens may test for more than 100 genetic conditions. The list of conditions screened for is called a panel. Common panels are 250 or 600 genes. Not all expanded carrier screens that are available analyse the same genes. Some may test for genes that do not cause serious disease, or cause diseases that occur in later life; others test for genes that cause severe conditions in childhood. There is no agreement as to which panel of genes should be tested for in an ECS. Understanding the screening that is being offered, and the meaning of any results, is complicated and requires support from appropriately trained professionals to best inform the prospective parent or parents. [ABSTRACT FROM AUTHOR]

Introduction Pathogenic mutations in POLE/POLD1 lead to decreased fidelity of DNA replication, resulting in a high tumor mutational burden (TMB-H), defined as TMB ≥ 10 mut/Mb, independent of deficient mismatch repair (dMMR) and microsatellite instability high (MSI-H) status. Methods De-identified records of patients with colorectal cancer (CRC) profiled with the Tempus xT assay (DNA-seq of 595-648 genes at 500×) were identified from the Tempus Database. Results Among 9136 CRC samples profiled, the frequency of POLE/POLD1 genomic alterations was 2.4% (n  = 217). Copy number loss was the most common genomic alteration (64%, n  = 138) of POLE/POLD1, followed by copy number amplifications (18%, n  = 40) and short variant mutations (18%, n  = 39). The POLE/POLD1 mutated group presented with a higher frequency of TMB-H phenotype relative to wild type (WT; 22% vs. 9%, P < .001), with a median TMB of 127 mut/Mb in the TMB-H POLE/POLD1 subset. The TMB showed a dramatic contrast between POLE/POLD1 short variant mutations as compared to the group with copy number alterations, with a TMB of 159 mut/Mb vs 15 mut/Mb, respectively. Thus, the short variant mutations represented the so-called ultra-hypermutated phenotype. The POLE/POLD1 mutated group, as compared to WT, exhibited a higher rate of coexisting mutations, including APC, ALK, ATM, BRCA2 , and RET mutations. Conclusion Patients with POLE/POLD1 mutations exhibited significant differences across immunological markers (ie, TMB, MMR, and MSI-H) and molecular co-alterations. Those with short variant mutations represented 18% of the POLE/POLD1 cohort and 0.4% of the total cohort examined. This group of patients had a median TMB of 159 mut/Mb (range 34-488), representing the ultra-hypermutated phenotype. This group of patients is important to identify given the potential for exceptional response to immune checkpoint inhibitors. [ABSTRACT FROM AUTHOR]

Purpose: The present study was conducted to determine the presence of Toxoplasma gondii in donkeys by molecular tests and genetic diversity analysis of the obtained DNA samples from central Kenya. Method: A total of 363 blood samples were collected from donkeys in Meru and Kirinyaga Counties, and 96 samples that were previously seropositive for T. gondii using indirect ELISA were subjected to nested PCR based on the amplification of the internal transcribed spacer 1 (ITS-1) gene followed by DNA sequencing and phylogenetic analysis. Genotyping was performed on 15 selected positive samples using multilocus nested polymerase chain reaction restriction fragment length polymorphism (Mn-PCR-RFLP) with eight genetic markers ('SAG 2, 5'SAG 2, Alt. SAG 2, SAG 3, GRA 6, C29-2, BTUB and L358). Results: Toxoplasma gondii DNA was detected in 36.5% (35/96) of the blood samples. The sequences obtained exhibited 98.2–99.5% homology with those deposited in GenBank. Phylogenetic analysis demonstrated that the obtained sequences are conserved and clustered with those of infecting animals from other regions of the world. Eighteen distinct T. gondii haplotypes were identified to be circulating in donkeys from central Kenya. The T. gondii DNA samples exhibited high haplotype diversity (Hd: 0.915) and limited genetic diversity (π = 0.01027). PCR-RFLP of T. gondii DNA-positive samples revealed three different genetic combinations that consisted of alleles I, II and III, indicating the dissemination of atypical genotypes. Conclusion: This study demonstrated that T. gondii is widespread in donkeys from Kenya and could be a possible source of infection in humans. These findings are important for designing control strategies for this parasite to improve the livestock sector, which is one of the main sources of livelihood for farmers in Kenya. [ABSTRACT FROM AUTHOR]

Non‐immune hydrops fetalis (NIHF) is a rare entity characterized by excessive accumulation of fluid within the fetal extravascular compartments and body cavities. Here we present two intrauterine fetal demises with NIHF presenting with oligohydramnios, cystic hygroma, pleural effusion, and generalized hydrops with predominance of subcutaneous edema. The fetuses also presented with ascites, severe and precocious IUGR and skeletal anomalies. Whole exome sequencing was applied in order to screen for a possible genetic cause. The results identified biallelic variants in MYBBP1A in both fetuses. A previous report described another case with a similar phenotype having compound heterozygous variants in the same gene. The protein encoded by MYBBP1A is involved in several cellular processes including the synthesis of ribosomal DNA, the response to nucleolar stress, and tumor suppression. Our functional protein analysis through immunohistochemistry indicates that MYBBP1A is a gene expressed during fetal stages. Altogether, we concluded that MYBBP1A is associated with the development of hydrops fetalis. More cases and further studies are necessary to understand the role of this gene and the mechanism associated with NIHF. [ABSTRACT FROM AUTHOR]

Background: The globally transmitted avian malaria parasite Plasmodium relictum (lineage SGS1) has been found to infect hundreds of different bird species with differences in infection outcomes ranging from more or less latent to potentially mortal. However, to date basic knowledge about the links between genetic differentiation and variation in infection outcome within this single malaria parasite species is lacking. Methods: In this study, two different isolates of SGS1, obtained in the wild from two different host species, were used to investigate differences in their development in the blood and virulence in the experimentally infected canaries. Simultaneously, 258 kb of the parasite genome was screened for genetic differences using parasite mRNA and compared between experimental groups. Results: The two isolates showed differences in development and caused mortality as well as effects on the blood parameters of their hosts. Although previous studies using single genes have shown very limited within lineage genetic diversity in the European population of SGS1, 226 SNPs were found across 322 genes, which separated the two experimental groups with a total of 23 SNPs that were fixed in either of the experimental groups. Moreover, genetic variation was found within each experimental group, hinting that each avian malaria infection harbours standing genetic variation that might be selected during each individual infection episode. Conclusion: These results highlight extensive genetic variation within the SGS1 population that is transferred into individual infections, thus adding to the complexity of the infection dynamics seen in these host–parasite interactions. Simultaneously, the results open up the possibility of understanding how genetic variation within the parasite populations is linked to the commonly observed differences in infection outcomes, both in experimental settings and in the wild. [ABSTRACT FROM AUTHOR]

Background: The WFS1 gene encodes the protein wolframin, which is crucial for maintaining endoplasmic reticulum homeostasis. Variants in this gene are predominantly associated with Wolfram syndrome and have been implicated in other disorders such as diabetes mellitus and psychiatric diseases, which increases the rate of clinical misdiagnosis. Methods: Patients were diagnosed with early-onset unclassified diabetes according to their clinical and laboratory data. We performed whole-exome sequencing (WES) in 165 patients, interpreting variants according to the American College of Medical Genetics/Association for Molecular Pathology (ACMG/AMP) 2015 guidelines. Variant verification was done by Sanger sequencing. In vitro experiments were conducted to evaluate the effects of WFS1 compound heterozygous variants. Results: We identified WFS1 compound heterozygous variants (p.A214fs*74/ p.F329I and p.I427S/p.I304T) in two patients with Wolfram Syndrome-Like disorders (WSLD). Both WFS1 compound heterozygous variants were associated with increased ER stress, reduced cell viability, and decreased SERCA2b mRNA levels. Additionally, pathogenic or likely pathogenic WFS1 heterozygous variants were identified in the other three patients. Conclusion: Our results underscore the importance of early genetic testing for diagnosing young-onset diabetes and highlight the clinical relevance of WFS1 variants in increasing ER stress and reducing cell viability. Incorporating these genetic insights into clinical practice can reduce misdiagnoses and improve treatment strategies for related disorders. [ABSTRACT FROM AUTHOR]

Multiple osteochondromas (MO) is a rare autosomal dominant skeletal disorder characterized by the development of multiple benign tumors known as osteochondromas. The condition is predominantly caused by loss-of-function variants in the EXT1 or EXT2 genes, facilitating relatively precise clinical diagnosis through established diagnostic criteria. Despite this, a notable percentage of MO cases (10%-20%) remains unresolved after sequencing coding regions and copy number analysis of both genes. In our study, we identified mosaic structural variants in two patients who initially yielded negative results on standard genetic analysis for MO. Specifically, mosaic deletions affecting exons 8-11 and exons 2-11 in the EXT1 gene were detected. RNA analysis was performed in one case, while both cases underwent genome sequencing. To date, only six mosaic copy number variations have been reported in association with MO, representing a minority among known variants in both genes. Our report provides a detailed analysis of these findings, highlighting the significance of advanced genetic testing techniques in detecting mosaic variants in the EXT1/2 genes. [ABSTRACT FROM AUTHOR]

Background: The biochemical and genetic characteristics of four very-longchain acyl-coenzyme A dehydrogenase deficiency (VLCADD) patients, clarifying their pathogenic genetic factors and evaluating the application value of genetic diagnosis in the early diagnosis of VLCADD, are reported and discussed in this article. Methods: Patients underwent blood tandem mass spectrometry (MS/MS), urine gas chromatography (GC/MS), and high-throughput sequencing technology. New variants were analyzed for pathogenicity using bioinformatics software. Swiss-PdbViewer software was used to predict the effect of variants on the structure of the very-long-chain acyl-CoA dehydrogenase (VLCAD) protein. Result: A total of four VLCADD patients were diagnosed. They revealed elevated levels of C14, C14:1, C14:2, C14:1/C2, C14:1/C10, and C14:1/C12:1. Two patients were early-onset neonatal cases and died during infancy and the neonatal period, respectively. Seven kinds of variants were detected, including four novel variants. Bioinformatics software revealed that the variants were harmful, and the Swiss-PdbViewer results suggest that variation affects protein conformation. Conclusion: This study identified four novel ACADVL gene variants. These findings contribute to the understanding of the genetic basis and pathogenesis of VLCADD. Meanwhile, the study enriches the genetic mutation spectrum and the correlation between genotypes and phenotypes of VLCADD, indicating that genetic diagnosis plays an essential role in the early diagnosis and treatment of VLCADD. [ABSTRACT FROM AUTHOR]

The purpose of this study was to analyze and molecularly describe the largest group of patients with ABCA4-associated retinal degeneration in Latin America. Pathogenic variants in ABCA4, a member of the ATP Binding Cassette (ABC) transporters superfamily, is one of the most common causes of inherited visual deficiency in humans. Retinal phenotypes associated with genetic defects in ABCA4 are collectively known as ABCA4-associated retinal degenerations (ABCA4R), a group of recessively inherited disorders associated with a high allelic heterogeneity. While large groups of Caucasian and Asiatic individuals suffering from ABCA4R have been well characterized, molecular information from certain ethnic groups is limited or unavailable, precluding a more realistic knowledge of ABCA4-related mutational profile worldwide. In this study, we describe the molecular findings of a large group of 211 ABCA4R index cases from Mexico. Genotyping was performed using either next generation sequencing (NGS) of a retinal dystrophy genes panel or exome. ABCA4 targeted mutation testing was applied to a subgroup of subjects in whom founder mutations were suspected. A total of 128 different ABCA4 pathogenic variants were identified, including 22 previously unpublished variants. The most common type of genetic variation was single nucleotide substitutions which occurred in 92.7% (408/440 alleles). According to the predicted protein effect, the most frequent variant type was missense, occurring in 83.5% of disease-causing alleles (368/440). Mutations such as p.Ala1773Val are fully demonstrated as a founder effect in native inhabitants of certain regions of Mexico. This study also gives us certain indications of other founder effects that need to be further studied in the near future. This is the largest molecularly characterized ABCA4R Latin American cohort, and our results supports the value of conducting genetic screening in underrepresented populations for a better knowledge of the mutational profile leading to monogenic diseases. [ABSTRACT FROM AUTHOR]

The SETD1B gene, located on chromosome 12q24, is one of the chromatin‐modifying genes involved in epigenetic regulation of gene transcription. The phenotype of pathogenic variants in the SETD1B gene includes intellectual disability, seizures, and language delay (IDDSELD, OMIM 619000). In this study, we present a family consisting of consanguineous parents who died of cancer and their offspring. This family includes two cases diagnosed with autism spectrum disorder (ASD); six cases diagnosed with schizophrenia, bipolar disorder, or schizoaffective disorder; there cases diagnosed with cancer; and five cases who died of unknown causes in early childhood. Three affected members of this family agreed to genetic testing. We used whole exome sequencing. We report a novel in‐frame deletion variant of the SETD1B gene in a family with cases diagnosed with schizoaffective disorder and ASD without seizures and intellectual disability. It was found that the phenotypic features were inherited for at least three generations in the family we presented, and it was shown that the pathogenic variant of the SETD1B gene was transmitted from the affected parent to his affected children. In addition, the father was diagnosed with both schizoaffective disorder and leukemia. We proposed an association between rare variants of SETD1B and phenotypes of ASD and schizoaffective disorder without seizures and intellectual disability. The SETD1B gene is included in both the ASD genetic database of SFARI (https://gene.sfari.org/) and the cancer database of COSMIC (https://cancer.sanger.ac.uk/cosmic). However, there are very few reports of SETD1B gene variants as clinical entities. To our knowledge, the SETD1B gene variant has not been previously reported in an individual diagnosed with both a neuropsychiatric disorder and cancer. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this study is to assess the carrier frequency and pathogenic variation of monogenetic diseases in a population of 114 subjects in Han Chinese from Hebei province who are undergoing assisted reproductive technology through the utilization of Expanded Carrier Screening (ECS). Methods: The study utilized a panel consisting of 155 severe monogenic recessive genetic diseases for ECS. Next-generation sequencing technology was employed to identify specific variants associated with ECS in a cohort of 114 subjects from 97 couples, comprising 97 females and 17 male spouses. Results: A total of 114 individuals received ECS. The carrier rate of pathogenic genes in the enrolled population was 44.74% (51/114). Among the 97 females, the carrier rate of pathogenic genes was higher in those without assisted reproduction indicators than in those with assisted reproduction indicators (59.09% vs. 41.33%). However, the carrier rate of pathogenic genes in males without assisted reproductive technology was slightly lower than that with assisted reproductive technology (40% vs. 41.67%). Among both female and male participants, the carrier rate of pathogenic genes between individuals without indicators of assisted reproduction and those with such indicators was 55.55% vs. 41.38%. In 51 carriers, 72.55% (37/51) carried one genetic variant, 25.49% (13/51) carried two genetic variants, and 1.96% (1/51) carried three genetic variants. A total of 38 pathogenic genes were detected in this study, and GJB2 and MMACHC were most common. The carrier rates of the two genes were both 5.26% (6/114). A total of 55 variations were detected, and c.235delC was most frequently found. The carrier rate was 3.51% (4/114). The incidence of couples carrying the same pathogenic genes was 1.03% (1/97). Conclusions: The findings elucidate the carrier rate of pathogenic genes among 155 severe monogenic recessive genetic diseases and underscore the significance of ECS as a preventive measure against congenital anomalies. When both partners carry the same genetic mutation for a monogenic disease, preventive strategies can be taken in offspring through preimplantation genetic testing (PGT), prenatal genetic testing, or the utilization of donor gametes. ECS is instrumental in assessing reproductive risk, guiding fertility-related decisions, and reducing the prevalence of monogenic recessive genetic disorders in subsequent generations. [ABSTRACT FROM AUTHOR]