Search

Purpose: Individuals with proximal 16p11.2 copy number variants (CNVs), either deletions (16p11.2DS) or duplications (16p11.2Dup), are predisposed to neurodevelopmental difficulties and disorders, such as language disorders, intellectual disability, and autism spectrum disorder. The purpose of the current study was to characterize language profiles of school-age children with proximal 16p11.2 CNVs, in relation to the normative sample and unaffected siblings of children with 16p11.2DS., Method: Standardized language tests were conducted in 33 school-age children with BP4-BP5 16p11.2 CNVs and eight unaffected siblings of children with 16p11.2DS to evaluate language production and comprehension skills across various language domains. A standardized intelligence test was also administered, and parents completed a standardized questionnaire to assess autistic traits. Language profiles were compared across 16p11.2 CNVs and intrafamilial pairs. The influence of nonverbal intelligence and autistic traits on language outcomes was investigated., Results: No significant differences were found between children with 16p11.2DS and those with 16p11.2Dup, although both groups exhibited significantly poorer language skills compared to the normative sample and unaffected siblings of children with 16p11.2DS. Severe language deficits were identified in 70% of individuals with 16p11.2 CNVs across all language subdomains, with significantly better receptive vocabulary skills than overall receptive language abilities. In children with 16p11.2DS, expressive language deficits were more pronounced than receptive deficits. In contrast, only in children with 16p11.2Dup did nonverbal intelligence influence their language outcomes., Conclusions: The current study contributes to the deeper understanding of language profiles in 16p11.2 CNVs in a clinically ascertained cohort, indicating generalized deficits across multiple language domains, rather than a syndrome-specific pattern targeting specific subdomains. The findings underscore the importance of early diagnosis, targeted therapy, and monitoring of language skills in children with 16p11.2 CNVs., Supplemental Material: https://doi.org/10.23641/asha.27228702.

Recurrent genomic rearrangements at 16p11.2 BP4-5 represent one of the most common causes of genomic disorders. Originally associated with increased risk for autism spectrum disorder, schizophrenia, and intellectual disability, as well as adiposity and head circumference, these CNVs have since been associated with a plethora of phenotypic alterations, albeit with high variability in expressivity and incomplete penetrance. Here, we comprehensively review the pleiotropy associated with 16p11.2 BP4-5 rearrangements to shine light on its full phenotypic spectrum. Illustrating this phenotypic heterogeneity, we expose many parallels between findings gathered from clinical versus population-based cohorts, which often point to the same physiological systems, and emphasize the role of the CNV beyond neuropsychiatric and anthropometric traits. Revealing the complex and variable clinical manifestations of this CNV is crucial for accurate diagnosis and personalized treatment strategies for carrier individuals. Furthermore, we discuss areas of research that will be key to identifying factors contributing to phenotypic heterogeneity and gaining mechanistic insights into the molecular pathways underlying observed associations, while demonstrating how diversity in affected individuals, cohorts, experimental models, and analytical approaches can catalyze discoveries., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Whereas 16p11.2 BP4-5 copy-number variants (CNVs) represent one of the most pleiotropic etiologies of genomic syndromes in both clinical and population cohorts, the mechanisms leading to such pleiotropy remain understudied. Identifying 73 deletion and 89 duplication carrier individuals among unrelated White British UK Biobank participants, we performed a phenome-wide association study (PheWAS) between the region's copy number and 117 complex traits and diseases, mimicking four dosage models. Forty-six phenotypes (39%) were affected by 16p11.2 BP4-5 CNVs, with the deletion-only, mirror, U-shape, and duplication-only models being the best fit for 30, 10, 4, and 2 phenotypes, respectively, aligning with the stronger deleteriousness of the deletion. Upon individually adjusting CNV effects for either body mass index (BMI), height, or educational attainment (EA), we found that sixteen testable deletion-driven associations-primarily with cardiovascular and metabolic traits-were BMI dependent, with EA playing a more subtle role and no association depending on height. Bidirectional Mendelian randomization supported that 13 out of these 16 associations were secondary consequences of the CNV's impact on BMI. For the 23 traits that remained significantly associated upon individual adjustment for mediators, matched-control analyses found that 10 phenotypes, including musculoskeletal traits, liver enzymes, fluid intelligence, platelet count, and pneumonia and acute kidney injury risk, remained associated under strict Bonferroni correction, with 10 additional nominally significant associations. These results paint a complex picture of 16p11.2 BP4-5's pleiotropic pattern that involves direct effects on multiple physiological systems and indirect co-morbidities consequential to the CNV's impact on BMI and EA, acting through trait-specific dosage mechanisms., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: We present first-trimester application of expanded non-invasive prenatal testing (NIPT) in the genetic investigation of fetal 1p36 deletion syndrome associated with a familial unbalanced reciprocal translocation of 46,XX,der(1)t(1;2) (p36.2;q37.3)dmat., Case Report: A 37-year-old, gravida 2, para 0, woman underwent expanded NIPT at 13 weeks of gestation because of advanced maternal age and the fear of complications of invasive procedures of prenatal diagnosis. She had experienced one spontaneous abortion. The pregnancy was conceived by in vitro fertilization and embryo transfer (IVF-ET) because of tubal occlusion. NIPT was positive for 1p36 deletion. At 17 weeks of gestation, she underwent amniocentesis but intrauterine fetal death occurred after amniocentesis and the pregnancy was terminated. Amniocentesis revealed a derivative chromosome 1 with an aberrant short arm terminal segment of chromosome 1. Subsequent cytogenetic analysis of parental bloods showed a karyotype of 46,XY in the father and a karyotype of 46,XX,t(1;2) (p36.2;q37.3) in the mother. The karyotype of amniocytes was 46,XX,der(1)t(1;2) (p36.2;q37.3)dmat, consistent with partial monosomy 1p (1p36.2→pter) and partial trisomy 2q (2q37.3→qter). Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from cultured amniocytes revealed the result of arr 1p36.33p36.22 (852,863-11,303,452) × 1.0 and arr 2q37.3 (242,785,405-243,068,396) × 3.0 [GRCh 37] with a 10.451-Mb deletion of 1p36.33-p36.22 encompassing 116 OMIM genes including RERE and a 283-kb duplication of 2q37.3 encompassing one OMIM gene of PDCD1., Conclusion: Expanded NIPT has the advantage of early detection of familial unbalanced reciprocal translocation in the fetus., Competing Interests: Declaration of competing interest The authors have no conflicts of interest relevant to this article., (Copyright © 2024. Published by Elsevier B.V.)

Background: Arising in the late 1990s, when a promising role in prenatal diagnostics was first delineated for circulating fetal DNA, non-invasive prenatal tests (NIPTs) have been increasingly used with more frequency and popularity. These exams have been used as a prenatal screening tests for genetic diseases. Initially, they were developed for the investigation of the main fetal chromosomal aneuploidies, but lately they have also been used to rule out genomic microrearrangements and monogenic conditions. However, along with great opportunities and potential, the tests can show inconclusive or unexpected results. Several studies have shown that the current pre-test counseling is often insufficient, and more oriented at providing pieces of information about the identifiable diseases rather than providing extensive information on all possible scenarios which may affect both the fetus and the pregnant mother, especially in the case of an invasive test for the pregnant mother., Methods and Results: We have gathered from the literature on NIPT the main pitfalls, imperfections, and particular cases associated with this innovative diagnostic procedure., Conclusions: In view of further improvements in the methods that can limit the inconclusive or unexpected results, this paper aims to reinforce the importance of more accurate pre-test counseling with comprehensive information about the above-mentioned questions, as well as ultrasound use and also the creation of an international consensus statement concerning these topics.

Background: Cat eye syndrome (CES) is a rare congenital disease frequently caused by a partial tetrasomy of the proximal long (q) arm of chromosome 22, due to a small supernumerary marker chromosome (sSMC). CES patients show remarkable phenotypic variability. Despite the progress of molecular cytogenetic technology, the cause of phenotypic variability and the genotype-phenotype correlations remain unknown., Methods: We analyzed clinical and genetic data of a new patient with CES together with 27 previously reported ones with a confirmed genomic gain in the PubMed database between 2012 and 2023., Results: We reported a boy with CES carrying a 22q11.1-q11.21 duplication of 1.76 Mb tetrasomy (16888900_18644241, hg19) who presented currently rare or unreported clinical findings such as congenital aural atresia, hearing loss, PLSVC, and IVC. The results of the whole exome sequencing (WES) showed a heterozygous mutation of the GJB2 gene (NM_004004.6: exon2: c.109G > A). In addition, the results of our literature review showed that the presence of a classical sSMC was the most frequent cytogenetic abnormality in CES (82%). 63% of cases were in a homogenous state and 37% of cases were in a mosaic state. 72% of cases had a 1-2 Mb duplication. In the majority of CES patients the breakpoints in chromosome 22 are localized to a 50 kb region (18610000_18660000 bp). The CES critical region (CESCR) may be further delimited to a 0.3 Mb region (17799398_18111588 bp). Within this region CECR2, SLC25A18, ATP6V1E1, and BCL2L13 are strong candidate genes for causing the main CES phenotype. The ear anomalies are the most frequent features in CES patients (89%) and hearing loss was present in 36% of CES patients., Conclusions: The phenotypic features in CES are highly variable. Our findings expand the symptom spectrum of CES and lay the foundation for better delineating the clinical phenotype, molecular cytogenetic features associated with CES and genotype-phenotype correlations. We recommend performing WES to rule out the involvement of other genetic factors in the patient's phenotype. In addition, our findings also highlight the need for genetic counseling and recurrence risk assessment., (© 2024. The Author(s).)

Objective: To explore the clinical features and genetic etiology of a fetus with 15q11q13 complex duplication syndrome., Methods: A fetus diagnosed with 15q11q13 duplication syndrome at Ningbo Women and Children's Hospital on April 19, 2023 was selected as the study subject. Clinical data was collected, and the fetus was subjected to invasive prenatal diagnosis including G-banded karyotyping and chromosomal microarray analysis (CMA). Following the discovery of chromosomal duplication, trio-whole exome sequencing was carried out to exclude single base variants and confirm the parental original of the duplication. Optical genome mapping was also performed to delineate the structural arrangement of the duplication. Relevant literature was searched in the PubMed, Wanfang Medical Network and CNKI databases using "15q11q13", "duplication", "hexasomy" and "Six fold repetition" as the key words from January 1, 2000 to August 1, 2023 for a review of previously reported 15q11q13 hexasomy cases. This study was approved by the Ningbo Women & Children's Hospital (Ethics No. EC2020-048)., Results: The fetus was found to have a mosaicism karyotype of 48,X?,+mar,+idic(15)(q13)[33]/47,X?,+idic(15)(q13)[17]. CMA and trio-WES have all shown a six-fold duplication in the PWS/AS critical region (PWACR) at 15q11.2q13.2 and quadruple duplication of 15q13.2q13.3 region, which have derived from its mother and formed supernumerary marker chromosomes (SMCs). Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the 15q11.2q13.2 sixfold duplication was classified as pathogenic, whilst the 15q13.2q13.3 quadruple duplication was classified as variant of uncertain significance. Literature search has identified 11 cases of 15q11q13 duplication involving hexasomy of the PWACR, with all cases showing mental retardation, language delay and hypotonia, and most of them also had motor retardation, epilepsy and mild facial dysmorphism., Conclusion: Hexasomy for the PWACR combined with tetrasomy of 15q13.2q13.3 probably underlay the left hand polydactyly, polyhydramnios and intrauterine growth retardation in this fetus.

Clinical application of serological screening and non-invasive prenatal testing (NIPT) both have difficulties to attain high detection rate and low cost. For its advantages of high detection rate, high sensitivity, simplicity, short turnaround time and low cost, digital PCR (dPCR) has provided a new choice for prenatal screening of trisomies 21, 18 and 13. To standardize the application of dPCR for prenatal screening, we have formulated this consensus by referring to relevant guidelines, expert consensus and latest literature, which has covered the basic requirements, application scope, pre-testing service, testing procedure, report interpretation, genetic counseling, and limitations for this technology.

Objective: To explore the genetic characteristics of a child with 18q terminal deletion syndrome., Methods: Clinical data of a child presented at the Lianyungang Maternal and Child Health Care Hospital on July 20, 2023 was collected. Peripheral blood sample from the child was subjected to G-banded chromosomal karyotyping and chromosomal microarray analysis (CMA). Relevant literature was searched from CNKI, WanFang and PubMed databases over the past decade (from November 1, 2013 to November 1, 2023) using keywords including "18q-syndrome", "18q deletion syndrome" and "18q terminal deletion". This study was approved by the Lianyungang Maternal and Child Health Care Hospital (Ethics No. LYG-MER2021017)., Results: The child, a 4-year-and-6-month-old female, had manifested short stature, intellectual disability, distinctive facial features, aortic regurgitation, auditory canal atresia, and white matter lesions. She was found to have a karyotype of 46,XX,del(18)(q21), whilst the result of CMA was arr[GRCh37]18q21.33q23(60065821_77317445)×1. Both of her parents were found to have a normal karyotype. Literature review has retrieved 7 reports which involved 11 cases with a terminal 18q23 deletion. The phenotypes of cardiac abnormalities have been diverse, with pulmonary stenosis, atrial septal defect and ventricular septal defect being most common., Conclusion: The 18q terminal deletion probably underlay the multiple congenital anomalies and mental retardation in this child.

Background and Purpose: The abnormalities of the long arm of chromosome 18 (18q) constitute a complex spectrum. We aimed to systematically analyze their MR imaging features. We hypothesized that there would be variable but recognizable white matter and structural patterns in this cohort., Materials and Methods: In this retrospective cohort study, we included pediatric patients with a proved abnormality of 18q between 2000-2022. An age- and sex-matched control cohort was also constructed., Results: Thirty-six cases, median MR imaging age 19.6 months (4.3-59.3), satisfied our inclusion criteria. Most were female (25, 69%, F:M ratio 2.2:1). Fifty MR imaging studies were analyzed, and 35 (70%) had delayed myelination. Two independent readers scored brain myelination with excellent interrater reliability. Three recognizable evolving MR imaging patterns with distinct age distributions and improving myelination scores were identified: Pelizaeus-Merzbacher disease-like (9.9 months, 37), intermediate (22 months, 48), and washed-out pattern (113.6 months, 53). Etiologically, MRIs were analyzed across 3 subgroups: 18q deletion (34, 69%), trisomy 18 (10, 21%), and ring chromosome 18 (5, 10%). Ring chromosome 18 had the highest myelination lag (27, P = .005) and multifocal white matter changes ( P  = .001). Trisomy 18 had smaller pons and cerebellar dimensions (anteposterior diameter pons, P = .002; corpus callosum vermis, P < .001; and transverse cerebellar diameter, P  = .04)., Conclusions: In this cohort of 18q chromosomal abnormalities, MR imaging revealed recognizable patterns correlating with improving brain myelination. Imaging findings appear to be on a continuum with more severe white matter abnormalities in ring chromosome 18 and greater prevalence of structural abnormalities of the pons and cerebellum in trisomy 18., (© 2024 by American Journal of Neuroradiology.)

Objective: The aim of this systematic review and meta-analysis was to assess the rate of genomic abnormalities detected in pregnancies with apparently isolated hydramnios and to explore the role of confirmed fetal phenotype., Data Sources: The PubMed, Cochrane Library, Google Scholar, and Scopus databases were searched up to May 4, 2024., Study Eligibility Criteria: Observational studies that were published after the year 2000, written in a European language, and that reported the genomic outcomes of pregnancies complicated by prenatally diagnosed isolated polyhydramnios were included in this meta-analysis., Methods: The main outcome was the incidence of genomic abnormalities, defined as chromosomal numerical or structural anomalies or monogenic syndromes, that were diagnosed prenatally or postnatally in neonates from pregnancies complicated by isolated polyhydramnios. Additional outcomes included the incidence of chromosomal abnormalities, including both numerical and structural aberrations of the chromosomes (detected by karyotype or chromosomal microarray), monogenic abnormalities (detected by next-generation sequencing or clinical genetic examination after the result of a normal karyotype or chromosomal microarray), genetic syndromes in general (diagnosed clinically with or without genetic confirmation), and structural abnormalities detected postnatally. Pooled proportions were calculated for each outcome., Results: A total of 12 studies (2561 pregnancies complicated by isolated hydramnios) were included in the meta-analysis. The pooled prevalence of genomic anomalies in fetuses with apparently isolated polyhydramnios (12 studies, 2634 fetuses) was 4.5% (95% confidence interval, 2.6-7.6). The pooled prevalence of chromosomal abnormalities (11 studies, 2427 fetuses) was 2.1% (95% confidence interval, 1.1-3.7). The proportion of major structural defects detected postnatally (9 studies, 1731 fetuses) was 2.9% (95% confidence interval, 1.5-5.4); in this particular subgroup (4 studies, 14 fetuses), the pooled prevalence of genomic anomalies was 29.8% (95% confidence interval, 11.3-58.6). A meta-regression analysis indicated that the rate of genomic anomalies was positively associated with the severity of hydramnios. In addition, the pooled rate of monogenic anomalies was 5.6% (95% confidence interval, 2-5; I 2 =58%) in the 2 studies that used next-generation sequencing for genomic diagnosis., Conclusion: This meta-analysis showed that the rate of genomic anomalies in apparently isolated polyhydramnios is 4.5%; approximately half of them are chromosomal abnormalities and the other half are nonchromosomal genomic anomalies. From a clinical standpoint, chromosomal microarray analysis and possibly next-generation sequencing could be considered even in cases of apparently isolated polyhydramnios; this may be even more important in cases with incomplete fetal phenotype. Further studies using next-generation sequencing and addressing cost-effectiveness issues would fine-tune such recommendations., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objectives: Our aim was to examine the prenatal profiles of pregnancies affected by an atypical chromosomal aberration, focusing on pathogenic copy-number variants (pCNVs). We also wanted to quantify the performance of combined first-trimester screening (cFTS) and a second-trimester anomaly scan in detecting these aberrations. Finally, we aimed to estimate the consequences of a policy of using non-invasive prenatal testing (NIPT) rather than invasive testing with chromosomal microarray analysis (CMA) to manage pregnancies identified as high risk by cFTS., Methods: This was a retrospective review of the Danish Fetal Medicine Database of all pregnant women who underwent cFTS and a risk assessment for trisomy 21 between 1 January 2008 and 31 December 2018. Chromosomal aberrations diagnosed prenatally, postnatally or from fetal tissue following pregnancy loss or termination of pregnancy were identified. Chromosomal aberrations were grouped into one of six categories: triploidy; common trisomy (13, 18 or 21); monosomy X; other sex-chromosome aberration (SCA); pCNV; and rare autosomal trisomy (RAT) or mosaicism. The prevalence of each aberration category was stratified by the individual cFTS markers and trisomy 21 risk estimate, and the size of each pCNV diagnosed by CMA was calculated., Results: We retrieved data on 565 708 pregnancies, of which 3982 (0.70%) were diagnosed with a fetal chromosomal aberration. cFTS identified 87% of the common trisomies, but it also performed well in identifying triploidies (86%), monosomy X (92%), atypical SCAs (58%) and RATs or mosaicisms (70%). pCNVs comprised 27% (n = 1091) of the chromosomal aberrations diagnosed overall, and the prevalence increased during the study period, as prenatal CMA was increasingly being performed. In pregnancies with a maternal age < 30 years, nuchal translucency (NT) thickness ≤ 95 th centile, pregnancy-associated plasma protein-A (PAPP-A) ≥ 1 multiple of the median, or trisomy 21 risk of ≤ 1 in 1000, the prevalence of pCNVs exceeded significantly the prevalence of trisomies 21, 18 and 13. Pregnancies affected by a pCNV had significantly increased NT and decreased levels of the maternal biomarkers PAPP-A and β-human chorionic gonadotropin compared with unaffected pregnancies. However, only 23% of these pregnancies screened positive on cFTS and 51% of pCNVs were not detected until after birth. Among high-risk pregnancies, pCNVs comprised 14% of diagnosed aberrations, and when other atypical aberrations were considered, conventional NIPT (screening for trisomies 21, 18 and 13 and monosomy X) would miss 27% of all pathogenic aberrations diagnosed from invasive testing following a high-risk cFTS result. Thus, 1 in 26 pregnancies at high risk following cFTS would be affected by a chromosomal aberration despite a normal result from conventional NIPT. In a contingent screening model using NIPT for the 'intermediate'-risk group (trisomy 21 risk of 1 in 100-299), 50% of the aberrations would be missed. In our cohort, 79% of the pCNVs diagnosed were < 5Mb and therefore not detectable using current forms of 'genome-wide' NIPT., Conclusions: As a by-product of screening for trisomies 21, 18 and 13, most triploidies and the majority of atypical SCAs, RATs and mosaicisms are detected before birth. However, only 23% of pCNVs are associated with a high-risk result according to cFTS and only half are diagnosed before birth. Replacing invasive testing with NIPT for high-risk pregnancies would substantially decrease the first-trimester detection of pathogenic chromosomal anomalies. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology., (© 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.)

Context: Chromosomal abnormalities in embryos are the most common cause of early spontaneous abortions. Chromosome 1p36 deletion syndrome (OMIM 607872) is the most common subtelomeric, terminal microdeletion syndrome., Objective: The study intended to analyze miscarriage samples using chromosomal microarray analysis (CMA), to explore the mechanism of chromosomal aberrations, and to identify the recurrence risk and a prenatal diagnostic strategy for couples experiencing spontaneous abortions., Design: The research team performed a narrative review by searching PubMed databases. The search used the keywords 1p36 deletion, CMA, karyotype analysis, FISH and aborted fetus. The team also conducted case studies using genetic analyses., Setting: The study took place at Wuxi Maternity and Child Health Care Hospital in Wuxi, Jiangsu, PR China., Participants: Out of 673 abortion samples, six had 1p36 deletions (0.89%). Participants were the six families who had had those spontaneous abortions., Outcome Measures: The research team evaluated the fetal samples using: (1) CMA, (2) karyotype analysis, and (3) novel fluorescence in-situ hybridization (FISH)., Results: The CMA showed that: (1) fetus 1 had a 1.75 MB microdeletion at the 1p36.32p36.31 band, which testing didn't detect in fetus 1's parents, but the research team couldn't exclude the possibility that one of the parents was a carrier of a chromosomal insertional translocation; and (2) fetus 2 had a 5.10 MB microdeletion at the 1p36.13p36.12 segment, and fetus 3 had a 9.21 MB deletion at the 1p36.33p36.22 band, and the high-resolution karyotype analysis and FISH of the parents of both fetuses appeared normal, indicating that the chromosomal abnormalities were de novo; (3) fetus 4 had a 9.28 MB deletion at 1p36.33p36.22, although the high-resolution karyotype analysis of fetus 4's parent was normal; (4) fetuses 5 and 6 had a 7.64 MB microdeletion at 1p36.33p36.23 and a 4.45 MB deletion at 1p36.33p36.32, respectively, although the parents of both fetuses waived further testing., Conclusions: This study provides the first report of recurrent spontaneous and sporadic abortions with 1p36 deletion syndrome. The CMA combined with a reasonable family-pedigree investigation can detect cryptic chromosomal aberrations in miscarriages and can determine the mechanism of the chromosomal variations. It thus is invaluable in assessing recurrence risk and providing appropriate prenatal diagnostic strategies for affected families.

Background: Phelan-McDermid syndrome (PMS) is a rare neurodevelopmental disorder caused by 22q13 deletions that include the SHANK3 gene or pathogenic sequence variants in SHANK3. It is characterized by global developmental delay, intellectual disability, speech impairment, autism spectrum disorder, and hypotonia; other variable features include epilepsy, brain and renal malformations, and mild dysmorphic features. Here, we conducted genotype-phenotype correlation analyses using the PMS International Registry, a family-driven registry that compiles clinical data in the form of family-reported outcomes and family-sourced genetic test results., Methods: Data from the registry were harmonized and integrated into the i2b2/tranSMART clinical and genomics data warehouse. We gathered information from 401 individuals with 22q13 deletions including SHANK3 (n = 350, ranging in size from 10 kb to 9.1 Mb) or pathogenic or likely pathogenic SHANK3 sequence variants (n = 51), and used regression models with deletion size as a potential predictor of clinical outcomes for 328 phenotypes., Results: Our results showed that increased deletion size was significantly associated with delay in gross and fine motor acquisitions, a spectrum of conditions related to poor muscle tone, renal malformations, mild dysmorphic features (e.g., large fleshy hands, sacral dimple, dysplastic toenails, supernumerary teeth), lymphedema, congenital heart defects, and more frequent neuroimaging abnormalities and infections. These findings indicate that genes upstream of SHANK3 also contribute to some of the manifestations of PMS in individuals with larger deletions. We also showed that self-help skills, verbal ability and a range of psychiatric diagnoses (e.g., autism, ADHD, anxiety disorder) were more common among individuals with smaller deletions and SHANK3 variants., Limitations: Some participants were tested with targeted 22q microarrays rather than genome-wide arrays, and karyotypes were unavailable in many cases, thus precluding the analysis of the effect of other copy number variants or chromosomal rearrangements on the phenotype., Conclusions: This is the largest reported case series of individuals with PMS. Overall, we demonstrate the feasibility of using data from a family-sourced registry to conduct genotype-phenotype analyses in rare genetic disorders. We replicate and strengthen previous findings, and reveal novel associations between larger 22q13 deletions and congenital heart defects, neuroimaging abnormalities and recurrent infections., (© 2024. The Author(s).)

Chromosomal karyotyping analysis has been considered as the gold standard for cytogenetic diagnosis and an effective measure for preventing birth defects. However, conventional karyotyping analysis relies heavily on manual recognition, which is time-consuming and labor-intensive. The application of an efficient intelligent chromosomal karyotyping precise auxiliary diagnosis system in clinical practice can significantly reduce the analysis time and greatly improve the efficiency, increase the detection rate for low-percentage mosaicisms, and promote homogenization between laboratories. This can effectively enhance the capacity and level of cytogenetic diagnosis. With the continuous application of such system in the field of karyotyping analysis, a substantial amount of clinical application data and experience has been accumulated. This consensus has been formulated after multiple rounds of discussion by experts from the clinical application collaboration group of the efficient intelligent chromosomal karyotyping precise auxiliary diagnosis system. It aims to provide a reference for peers to better utilize intelligent auxiliary diagnosis systems during chromosomal karyotyping analysis and promote the standardized development of karyotyping analysis technology.

Objective: To explore the clinical characteristics and genetic etiology of four children with Phelan-McDermid syndrome (PMS)., Methods: Four children who had visited the Ningbo Women and Children's Hospital between June 2, 2022 and May 8, 2023 were selected as the study subjects. Clinical data of the children were collected. Genomic DNA was extracted from peripheral blood samples of the children and their parents and subjected to whole exome sequencing (WES). Candidate variants were verified by Sanger sequencing and quantitative PCR (q-PCR) analysis., Results: All children had presented with speech and language delays and intellectual disability. Children 3 and 4 also presented with autistic behaviors. WES showed that the children 1 and 2 had respectively carried a heterozygous c.731T>C (p.Leu244Pro) and a c.2782&#95;2851del (p.Gly928ArgfsTer4) variant of the SHANK3 gene. Sanger sequencing confirmed that their parents did not carry the same variant, suggesting that they were de novo in origin. Children 3 and 4 had respectively harbored a 121 Kb and 52.02 Kb heterozygous deletion at chromosome 22q13.33, which had both encompassed the SHANK3 and ACR genes mapped to 22q13.33. q-PCR results showed that the deletion of SHANK3 and ACR genes were de novo in origin. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.731T>C and c.2782&#95;2851del variants were predicted to be likely pathogenic (PS2+PM2&#95;Supporting+PP3) and pathogenic (PVS1+PM2&#95;Supporting+PS2&#95;Supporting), respectively. Furthermore, the 52.02 Kb and 121 Kb heterozygous deletions in 22q13.33 were both predicted to be pathogenic (2D+4C, 1.05 in score; 2D+4C, 1 in score)., Conclusion: The four children were all diagnosed with PMS by genetic testing. Above finding has enriched the phenotypic and mutational spectrum of PMS, and provided a basis for clinical diagnosis and genetic counseling for their families.

Background: Chromosome 16p11.2 deletions and duplications were found to be the second most common copy number variation (CNV) reported in cases with clinical presentation suggestive of chromosomal syndromes. Chromosome 16p11.2 deletion syndrome shows remarkable phenotypic heterogeneity with a wide variability of presentation extending from normal development and cognition to severe phenotypes. The clinical spectrum ranges from neurocognitive and global developmental delay (GDD), intellectual disability, and language defects (dysarthria /apraxia) to neuropsychiatric and autism spectrum disorders. Other presentations include dysmorphic features, congenital malformations, insulin resistance, and a tendency for obesity. Our study aims to narrow the gap of knowledge in Saudi Arabia and the Middle Eastern and Northern African (MENA) region about genetic disorders, particularly CNV-associated disorders. Despite their rarity, genetic studies in the MENA region revealed high potential with remarkable genetic and phenotypic novelty., Results: We identified a heterozygous de novo recurrent proximal chromosome 16p11.2 microdeletion by microarray (arr[GRCh38]16p11.2(29555974&#95;30166595)x1) [(arr[GRCh37]16p11.2(29567295&#95;30177916)x1)] and confirmed by whole exome sequencing (arr[GRCh37]16p11.2(29635211&#95;30199850)x1). We report a Saudi girl with severe motor and cognitive disability, myoclonic epilepsy, deafness, and visual impairment carrying the above-described deletion. Our study broadens the known phenotypic spectrum associated with recurrent proximal 16p11.2 microdeletion syndrome to include developmental dysplasia of the hip, optic atrophy, and a flat retina. Notably, the patient exhibited a rare combination of microcephaly, features consistent with the Dandy-Walker spectrum, and a thin corpus callosum (TCC), which are extremely infrequent presentations in patients with the 16p11.2 microdeletion. Additionally, the patient displayed areas of skin and hair hypopigmentation, attributed to a homozygous hypomorphic allele in the TYR gene., Conclusion: This report expands on the clinical phenotype associated with proximal 16p11.2 microdeletion syndrome, highlighting the potential of genetic research in Saudi Arabia and the MENA region. It underscores the importance of similar future studies., (© 2024. The Author(s).)

Objective: This study aimed to comprehensively analyze the detection capacity of non-invasive prenatal testing (NIPT) for chromosomal abnormalities of all 24 chromosomes, as well as high-risk indications for pregnancy and the fetal fraction, in a large cohort., Methods: We retrospectively enrolled 118,969 pregnant women who underwent NIPT at Sichuan Provincial Maternity and Child Health Care Hospital from March 2019 to June 2022. The sensitivity, specificity, positive predictive value, negative predictive value, and positive chromosomal abnormality rate were calculated. The fetal fraction based on gestational age, maternal body mass index, and number was examined., Results: NIPT demonstrated > 99% sensitivity and specificity for almost all of the common trisomies (T21, T18, and T13), sex chromosomal aneuploidies, rare autosomal trisomies, and microdeletion/microduplication syndromes. Positive predictive values varied from 12.0% to 89.6%. Advanced maternal age was associated with an increased risk of three major aneuploidies. The fetal fraction was positively correlated with gestational age and negatively correlated with the maternal body mass index., Conclusions: NIPT can be used to effectively screen for chromosomal abnormalities across all 24 chromosomes. Advanced maternal age is a risk factor for high-risk pregnancy, and careful consideration of the fetal fraction is essential during NIPT., Competing Interests: Declaration of conflicting interestThe authors declare that there is no conflict of interest.

Genetic counseling of mosaic and non-mosaic tetrasomy 9p remains difficult because of the possible associated congenital abnormalities, cytogenetic discrepancy in various tissues, true-positive and false-positive diagnosis in non-invasive prenatal testing (NIPT), uniparental disomy (UPD) 9, tissue-limited mosaicism, perinatal progressive decrease of the aneuploid cell line, phenotypic normal carriers and possible favorable fetal outcome in the cases with mosaic tetrasomy 9p at amniocentesis. This article presents a comprehensive review of various counseling issues concerning mosaic and non-mosaic tetrasomy 9p at prenatal diagnosis, and the information provided is very useful for genetic counseling under such circumstances., Competing Interests: Declaration of competing interest The authors have no conflicts of interest relevant to this article., (Copyright © 2024. Published by Elsevier B.V.)

What is the definition of Syndrome? Since the beginning of studies in genetics, certain terminologies have been created and used to define groups of diseases or alterations. With the advancement of knowledge and the emergence of new technologies, the use of basic concepts is being done in a mistaken or often confusing way. Because of this, revisiting and readjusting the old terms becomes imminent. Here, we explore these concepts and their use, through a literature compilation of an already well-defined genetic alteration (16q11.2 microduplication). We bring comparisons in clinical and molecular scope of the alteration itself and its diagnostic methods, to improve the report of cases, rescuing terminologies and their applicability nowadays., (© 2024 John Wiley & Sons Ltd.)

Background: Contiguous gene deletion in the short arm of chromosome 4 is linked to various neurodevelopmental disorders., Methods: In this study, we conducted peripheral blood chromosome G-banding karyotyping and whole-exome sequencing (WES) on a proband presenting with anal atresia, global developmental delay, lymphocytosis, and other multisystem anomalies. Additionally, chromosome G-banding karyotyping was also carried out on the proband's parents and brother., Results: The 7-month-old proband was found to have a 26.738 Mb 4p15.33-p14 deletion as identified by chromosome G-banding karyotyping and WES., Conclusion: We identified a patient with proximal 4p deletion syndrome by karyotype and WES analysis, which might explain some of his phenotypes. Our research enhances clinicians' knowledge of this rare condition, and offers valuable genetic counseling to the affected family. Further research is necessary to identify the causative gene or critical region associated with proximal 4p deletion syndrome., (© 2024 The Author(s). Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Purpose: This is a retrospective comparative study. We aimed to analyze the results of karyotype and chromosomal microarray analysis (CMA) of amniotic fluid across different gestational weeks and evaluate the clinical value in prenatal diagnosis, particularly in the late pregnancies., Methods: Samples from 580 pregnant women of 18-23 weeks of gestation (mid-gestation group) and 196 pregnant women of 24-32 weeks of gestation (late group) were performed both standard G-band karyotype analysis and CMA., Results: Among the 580 pregnant women in the routine group, the most common indications were positive Down's screening (213/580, 36.7%), followed by advanced maternal age (196/580, 33.8%); while fetal structural anomalies on ultrasonography were the top reason for amniocentesis in the late group (56/196, 28.6%). In the routine group, the total detection rate was 12.1% (70/580), of which 4.1% (24/580) were identified by karyotype analysis and 11.2% (65/580) by CMA. The total detection rate was 15.3% (30/196) in the late group, of which 5.1% (10/196) were detected by karyotype analysis, and 14.3% (28/196) by CMA., Conclusion: Karyotype analysis and CMA are complementary in detecting chromosomal abnormalities. Amniotic cavity puncture in the karyotype analysis in 18-23 weeks of gestation and 24-32 weeks of gestation is safe and effective, more obvious effect on the latter., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Sudden unexpected postnatal collapse (SUPC) is a sudden collapse of the clinical conditions of a full-term or near-term newborn, within the first 7 days of life, that requires resuscitation with positive ventilation and who either dies, has hypoxic-ischemic encephalopathy, or requires intensive care. The incidence of SUPC is very low, and most often presents a negative prognosis. The BUB1B gene is a mitotic checkpoint of serine/threonine kinase B that encodes a protein crucial for maintaining the correct number of chromosomes during cell division. Mutations in the BUB1B gene are linked to mosaic variegated aneuploidy syndrome 1 (MVA1), a rare autosomal recessive disorder characterized by diffuse mosaic aneuploidies involving several chromosomes and tissues. This paper discusses a case of a newborn who had a spontaneous delivery. After 2 h and 10 min, the infant showed generalized hypotonia and cyanosis, and his doctors performed orotracheal intubation, cardiac massage, pharmacological hemodynamic therapy, mechanical ventilation, antibiotic therapy, and hypothermic treatment. The newborn was discharged after 5 months with the diagnosis of hypoxic-ischemic encephalopathy. Suspecting an SUPC, a complete genetic analysis was performed demonstrating a compound heterozygous mutations in the BUB1B gene. The newborn died at 6 months of life, 1 month after discharge. A complete autopsy was performed, determining that the cause of death was due to sepsis starting from a brocopneumonic process, with outcomes of hypoxic-ischemic encephalopathy (HIE). In this scenario, it is not possible to demonstrate the causal effect of this mutation, considering that it could play a causal or concausal role in the onset of SUPC. Further research based on multicenter studies, as well as on animal models, could be very useful to clarify the pathological effect of this mutation., (© 2024. The Author(s).)

Using a new analytic method ("unique non-overlapping region" (UNOR) analysis), we characterized the genotypes and phenotypes of a large cohort of individuals diagnosed with chromosome 9p deletion syndrome (9PMS) and defined critical genomic regions. We extracted phenotypic information from 48 individuals with 9PMS from medical records and used a guided interview with caregivers to clarify ambiguities. Using high-resolution whole-genome sequencing for breakpoint definition, we aligned deletions and drew virtual breakpoints to obtain UNORs associated with phenotypic characteristics. We next extracted genotype and phenotype data for 57 individuals identified from a systematic review of the 9PMS literature and analyzed these as above. Common phenotypic features included developmental delay/intellectual disability, dysmorphic features, hypotonia, genital defects in XY individuals, psychiatric diagnoses, chronic constipation, atopic disease, vision problems, autism spectrum disorder, gastroesophageal reflux disease, trigonocephaly, congenital heart disease, and neonatal hypoglycemia. Our approach confirmed previous literature reports of an association of FREM1 with trigonocephaly and suggested a possible modifier element for this phenotype. In conclusion, the UNOR approach delineated phenotypic characteristics for 9PMS and confirmed the critical role of FREM1 and a possible long-distance regulatory element in pathogenesis of trigonocephaly that will need to be replicated in future studies., (© 2024. The Author(s), under exclusive licence to European Society of Human Genetics.)

This study reports three patients with Cat-eye Syndrome (CES), two of which present a previous clinical diagnosis of Craniofacial microsomia (CFM). Chromosomal microarray analysis (CMA) revealed a tetrasomy of 1,7 Mb at the 22q11.2q11.21 region, which is the typical region triplicated in the CES, in all patients. The most frequent craniofacial features found in individuals with CFM and CES are preauricular tags and/or pits and mandibular hypoplasia. We reinforce that the candidate genes for CFM features, particularly ear malformation, preauricular tags/pits, and facial asymmetry, can be in the proximal region of the 22q11.2 region., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Mosaic variegated aneuploidy (MVA) is a rare condition in which abnormal chromosome counts (that is, aneuploidies), affecting different chromosomes in each cell (making it variegated) are found only in a certain number of cells (making it mosaic). MVA is characterized by various developmental defects and, despite its rarity, presents a unique clinical scenario to understand the consequences of chromosomal instability and copy number variation in humans. Research from patients with MVA, genetically engineered mouse models and functional cellular studies have found the genetic causes to be mutations in components of the spindle-assembly checkpoint as well as in related proteins involved in centrosome dynamics during mitosis. MVA is accompanied by tumour susceptibility (depending on the genetic basis) as well as cellular and systemic stress, including chronic immune response and the associated clinical implications., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. Springer Nature Limited.)

Rho-associated protein kinase-2 (ROCK2) is a critical player in many cellular processes and was incriminated in cardiovascular and neurological disorders. Recent evidence has shown that non-selective pharmacological blockage of ROCKs ameliorates behavioral alterations in a mouse model of 16p11.2 haploinsufficiency. We had revealed that 16p11.2-deficient mice also display cerebrovascular abnormalities, including endothelial dysfunction. To investigate whether genetic blockage of ROCK2 also exerts beneficial effects on cognition and angiogenesis, we generated mice with both 16p11.2 and Rock2 haploinsufficiency (16p11.2 df/+ ;Rock2 +/- ). We find that Rock2 heterozygosity on a 16p11.2 df/+ background significantly improved recognition memory. Furthermore, brain endothelial cells from 16p11.2 df/+ ;Rock2 +/- mice display improved angiogenic capacity compared to cells from 16p11.2 df/+ littermates. Overall, this study implicates Rock2 gene as a modulator of 16p11.2-associated alterations, highlighting its potential as a target for treatment of autism spectrum disorders., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Chromosomal abnormalities are associated with a broad spectrum of clinical manifestations, one of the more commonly observed of which is epilepsy. The frequency, severity, and type of epileptic seizures vary according to the macro- and microrearrangements present. Even within a single chromosomal anomaly, we most often deal with a phenotypic spectrum. The aim of the study was to look for chromosomal rearrangements with a characteristic electroencephalographic pattern. Only a few disorders have peculiar electroclinical abnormalities: 1p36, 4p16, 6q terminal or trisomy 12p, Angelman syndrome, inv dup 15, 15q13.3 deletions, ring 20, Down syndrome, or Xp11.22-11.23 duplication. We also reviewed studies on epileptic seizures and typical electroencephalographic patterns described in certain chromosomal rearrangements, focusing on the quest for potential electroclinical biomarkers. The comprehensive review concludes with clinical presentations of the most common micro and macro chromosomal rearrangements, such as 17q21.31 microdeletion, 6q terminal deletion, 15q inv dup syndrome, 2q24.4 deletion, Xp11.22-11.23 duplication, 15q13.3 microdeletion, 1p36 terminal deletion, 5q14.3 microdeletion, and Xq28 duplication. The papers reviewed did not identify any specific interictal electroencephalographic patterns that were unique and significant biomarkers for a given chromosomal microrearrangement. The types of seizures described varied, with both generalized and focal seizures of various morphologies being reported. Patients with chromosomal anomalies may also meet the criteria for specific epileptic syndromes such as Infantile Epilepsy Spasms Syndrome (IESS, West syndrome): 16p13.11, 15q13.3 and 17q21.31 microdeletions, 5q inv dup. syndrome; Dravet syndrome (2q24.4 deletion), Lennox-Gastaut syndrome (15q11 duplication. 1q13.3, 5q inv dup.); or Self-Limited Epilepsy with Autonomic Features (SeLEAS, Panayiotopoulos syndrome: terminal deletion of 6q.n), Self-Limited Epilepsy with Centrotemporal Spikes (SeLECT): fragile X syndrome. It is essential to better characterize groups of patients to more accurately define patterns of epilepsy and EEG abnormalities. This could lead to new treatment strategies. Future research is required to better understand epileptic syndromes and chromosomal rearrangements. PLAIN LANGUAGE SUMMARY: This paper presents EEG recording abnormalities in patients with various gene abnormalities that can cause epilepsy. The authors summarize these EEG variations based on a literature review to see if they occur frequently enough in other chromosomal abnormalities (in addition to those already known) to be a clue for further diagnosis., (© 2024 The Authors. Epilepsia Open published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Pallister-Killian syndrome (PKS; OMIM #601803) is a rare genetic disorder typically characterized by developmental delay, seizures, sparse temporal hair, and facial dysmorphisms. PKS is most frequently caused by mosaic supernumerary isochromosome 12p. Here, we report a 27-month-old girl with a prenatal diagnosis of PKS and a histopathological diagnosis of pineocytoma., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

3q29 deletion syndrome (3q29del) is associated with neuropsychiatric and neurodevelopmental phenotypes. We previously reported that graphomotor weakness is present in up to 78% of individuals with 3q29del. We have now explored nuances of the graphomotor phenotype and its association with other comorbidities in this population. Participants were recruited from the online 3q29 registry (3q29deletion.org) for two days of deep phenotyping. 32 individuals with 3q29del (62.5% male) were evaluated with the Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI) to assess visual-motor integration. Participants were also evaluated with measures of cognitive ability, executive function, adaptive behavior, and school function. Males with 3q29del performed significantly worse than females on the VMI and Motor Coordination subtest. VMI performance was significantly associated with ADHD diagnosis and cognitive ability. Compared to published data from individuals with 22q11.2 deletion syndrome, individuals with 3q29del showed significantly more impairment. The 3q29 deletion is associated with substantial deficits in visual-motor integration, Visual Perception, and Motor Coordination. Our data suggests that 3q29del may qualify as a nonverbal learning disability. Future studies should assess whether individuals with 3q29del would benefit from early interventions, including occupational therapy., (© 2023. The Author(s).)

Background: Chromosome 18p deletion syndrome is caused by total or partial deletion of the short arm of chromosome 18 and associated with cognitive impairment, growth retardation and mild facial dysmorphism. However, most studies on the genotype-phenotype correlations in the 18p region are diagnosed postnatally. Prenatal reports involving 18p deletions are limited., Methods: Three pregnant women opted for invasive prenatal testing due to noninvasive prenatal testing indicating high risk for chromosome 18 abnormalities. Karyotypic analysis and chromosomal microarray analysis (CMA) were performed simultaneously. The pregnancy outcomes for all cases were followed up. Meanwhile, we also made a literature review on prenatal phenotypes of 18p deletions., Results: G-banding analysis showed that 2 fetuses presented abnormal karyotypes: 45,XN,der(18)t(18;21)(p11; q11),-21 (case 2) and 46,XN,18p- (case 3). The karyotype of case 1 was normal. Meanwhile, CMA detected 4.37 Mb (case 1), 7.26 Mb (case 2) and 14.97 Mb (case 3) deletions in chromosome 18p region. All 3 pregnancies were terminated finally according to genetic counseling based upon abnormal CMA results., Conclusion: Prenatal diagnosis of 18p deletion syndrome is full of challenges due to the phenotypic diversity, incomplete penetrance and lack of prenatal phenotypes. Increased nuchal translucency and holoprosencephaly are common prenatal phenotypes of distal 18p deletion. For fetuses carrying 18p deletions with atypical sonographic phenotypes, noninvasive prenatal testing could be adopted as an effective approach., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Chromosomal 16p11.2 deletions and duplications are genomic disorders which are characterized by neurobehavioral abnormalities, obesity, congenital abnormalities. However, the prenatal phenotypes associated with 16p11.2 copy number variations (CNVs) have not been well characterized. This study aimed to provide an elaborate summary of intrauterine phenotypic features for these genomic disorders., Methods: Twenty prenatal amniotic fluid samples diagnosed with 16p11.2 microdeletions/microduplications were obtained from pregnant women who opted for invasive prenatal testing. Karyotypic analysis and chromosomal microarray analysis (CMA) were performed in parallel. The pregnancy outcomes and health conditions of all cases after birth were followed up. Meanwhile, we made a pooled analysis of the prenatal phenotypes in the published cases carrying 16p11.2 CNVs., Results: 20 fetuses (20/20,884, 0.10%) with 16p11.2 CNVs were identified: five had 16p11.2 BP2-BP3 deletions, 10 had 16p11.2 BP4-BP5 deletions and five had 16p11.2 BP4-BP5 duplications. Abnormal ultrasound findings were recorded in ten fetuses with 16p11.2 deletions, with various degrees of intrauterine phenotypic features observed. No ultrasound abnormalities were observed in any of the 16p11.2 duplications cases during the pregnancy period. Eleven cases with 16p11.2 deletions terminated their pregnancies. For 16p11.2 duplications, four cases gave birth to healthy neonates except for one case that was lost to follow-up., Conclusions: Diverse prenatal phenotypes, ranging from normal to abnormal, were observed in cases with 16p11.2 CNVs. For 16p11.2 BP4-BP5 deletions, abnormalities of the vertebral column or ribs and thickened nuchal translucency were the most common structural and non-structural abnormalities, respectively. 16p11.2 BP2-BP3 deletions might be closely associated with fetal growth restriction and single umbilical artery. No characteristic ultrasound findings for 16p11.2 duplications have been observed to date. Given the variable expressivity and incomplete penetrance of 16p11.2 CNVs, long-term follow-up after birth should be conducted for these cases., (© 2024. The Author(s).)

Background: Small supernumerary marker chromosomes (sSMCs) are additional chromosomes with unclear structures and origins, and their correlations with clinical fetal phenotypes remain incompletely understood, which reduces the accuracy of genetic counseling., Methods: We conducted a retrospective analysis of a cohort of 36 cases of sSMCs diagnosed in our center. We performed G-banding and chromosomal microarray analysis (CMA). The resulting karyotypes were compared with case reports in the literature and various databases including OMIM, DECIPHER, ClinVar, ClinGen, ISCA, DGV, and PubMed., Results: Karyotype analysis data revealed that 19 out of 36 fetuses were mosaic. Copy number variants (CNVs) analysis results showed that 27 out of 36 fetuses harbored pathogenic/likely pathogenic variants. Among these 27 cases, 11 fetuses carried sex chromosome-related CNVs, including 4 female cases exhibiting Turner syndrome phenotypes and 7 cases showing Y chromosome deletions. In the remaining 16 fetuses with autosomal CNVs, 9 fetuses carried variants associated with Cat eye syndrome, Emanuel syndrome, Tetrasomy 18p, and 15q11-q13 duplication syndrome. Among these, 22 fetuses were terminated, and the remaining 5 fetuses were delivered and developed normally. Additionally, we identified a few variants with unclear pathogenicity., Conclusion: Cytogenetic analysis is essential for identifying the pathogenicity of sSMCs and increasing the accuracy of genetic counseling., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Schizophrenia is a neuropsychiatric disorder characterized by various symptoms such as hallucinations, delusions, and disordered thinking. The etiology of this disease is unknown; however, it has been linked to many microdeletion syndromes that are likely to contribute to the pathology of schizophrenia. In this review we have comprehensively analyzed the role of various microdeletion syndromes, like 3q29, 15q13.3, and 22q11.2, which are known to be involved with schizophrenia. A variety of factors lead to schizophrenia phenotypes, but copy number variants that disrupt gene regulation and impair brain function and cognition are one of the causes that have been identified. Multiple case studies have shown that loss of one or more genes in the microdeletion regions lead to brain activity defects. In this article, we present a coherent paradigm that connects copy number variations (CNVs) to numerous neurological and behavioral abnormalities associated with schizophrenia. It would be helpful in understanding the different aspects of the microdeletions and how they contribute in the pathophysiology of schizophrenia., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

With the gradual liberalization of the three-child policy and the development of assisted reproductive technology in China, the number of women with high-risk pregnancies is gradually increasing. In this study, 4211 fetuses who underwent chromosomal microarray analysis (CMA) with high-risk prenatal indications were analysed. The results showed that the overall prenatal detection rate of CMA was 11.4% (480/4211), with detection rates of 5.82% (245/4211) for abnormal chromosome numbers and 5.58% (235/4211) for copy number variants. Additionally, the detection rates of clinically significant copy number variants were 3.78% (159/4211) and 1.8% (76/4211) for variants of uncertain significance. The detection rates of fetal chromosomal abnormalities were 6.42% (30/467) for pregnant women with advanced maternal age (AMA), 6.01% (50/832) for high-risk maternal serum screening (MSS) results, 39.09% (224/573) with abnormal non-invasive prenatal testing (NIPT) results, 9.21% (127/1379) with abnormal ultrasound results, and 5.1% (49/960) for other indications. Follow-up results were available for 4211 patients, including 3677 (3677/4211, 87.32%) whose infants were normal after birth, 462 (462/4211, 10.97%) who terminated their pregnancy, 51 (51/4211, 1.21%) whose infants were abnormal after birth, and 21 (21/4211, 0.50%) who refused follow-up. The results of this study demonstrate significant variation in the diagnostic rate of chromosomal microarray analysis across different indications, providing valuable guidance for clinicians to assess the applicability of CMA technology in prenatal diagnosis., (© 2024. The Author(s).)

Background: 2q37 microdeletion syndrome is a rare clinical condition characterized by a series of physical abnormalities. Its Albright hereditary osteodystrophy (AHO)-like manifestations and possible complication of biochemical abnormalities indicating PTH resistance greatly increased the likelihood of misdiagnosis with classic pseudohypoparathyroidism (PHP) caused by GNAS mutation or methylation alteration, even though there have only been six reports of such clinical occasions., Purpose: to investigate the underlying genetic defect in a male patient presenting hypocalcemia, elevated PTH and with a history of kyphosis., Method: clinical information was collected, while the DNA was extracted from peripheral blood and subjected to methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) and exome sequencing., Result: Physical characteristics featuring short stature, obesity, round face, short neck, and shortened 4 th metacarpal and laboratory examination of the patient suggested the presence of PTH resistance, which is indicative of PHP. MS-MLPA did not reveal methylation alterations or deletions of GNAS, STX16 or other monogenetic alterations responsible for iPPSDs, but WES revealed a long-range deletion of approximately 4.18 Mb of the 2q37 region that spanned AGAP1 to NDUFA10, indicating that the patient had 2q37 microdeletion syndrome with PTH resistance., Conclusion: After undergoing MS-MLPA and exome sequencing, a novel deletion spanning 4.18 Mb on the 2q37 region was identified in one male patient, clarifying the diagnosis of 2q37 microdeletion syndrome with PTH resistance. The new genetic discovery added to our understanding of the molecular defects that cause inactivating PTH/PTH-related protein signaling disorders (iPPSDs)., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: This study evaluated the BACs-on-Beads™ (BoBs) efficiency assay in detecting chromosomal anomalies in products of conception (POC) specimens associated with anembryonic pregnancy (AP) among Thai pregnant women., Method: Retrospective analysis applied the BoBs™ assay to examine AP samples from 2010 to 2022. The incidences of AP with chromosomal abnormalities were reported., Result: Assessment of villi from anembryonic pregnancy samples found normal chromosome complement in 50% of the cases, while the remainder showed chromosomal abnormalities. Trisomy 16 was found in 15% of the cases and trisomies 22, 15, and 19 in 9.6%, 3.8%, and 3.8%, respectively. Advanced maternal age was associated with a higher incidence of aneuploidy., Conclusion: The BoBs™ assay effectively detected diverse chromosomal abnormalities in villi samples from POC. The diagnostic utility of the BoBs™ assay was highlighted in identifying chromosomal irregularities in AP cases. Trisomy 16 possessed the most chromosomal abnormalities in the AP samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Patients with chromosome 18q deletion syndrome generally experience hypogammaglobulinemia. Herein, we describe two patients with chromosome 18q deletion syndrome who presented with late-onset combined immune deficiency (LOCID), which has not been previously reported. Patient 1 was a 29-year-old male with 18q deletion syndrome, who was being managed for severe motor and intellectual disabilities at the Yamabiko Medical Welfare Center for 26 years. Although the patient had few infections, he developed Pneumocystis pneumonia at the age of 28. Patient 2, a 48-year-old female with intellectual disability and congenital malformations, was referred to Tokyo Medical and Dental University Hospital with abnormal bilateral lung shadows detected on her chest radiography. Computed tomography showed multiple lymphadenopathies and pneumonia. A lymph node biopsy of the inguinal region revealed granulomatous lymphadenitis, and a chromosomal examination revealed 18q deletion. Array-based genomic hybridization analysis revealed deletion at 18q21.32-q22.3 for patient 1 and at 18q21.33-qter for patient 2. Immune status work-up of the two patients revealed panhypogammaglobulinemia, decreased number of memory B cells and naïve CD4 + and/or CD8 + cells, reduced response on the carboxyfluorescein diacetate succinimidyl ester T-cell division test, and low levels of T-cell receptor recombination excision circles and Ig κ-deleting recombination excision circles. Consequently, both patients were diagnosed with LOCID. Although patients with 18q deletion syndrome generally experience humoral immunodeficiency, the disease can be further complicated by cell-mediated immunodeficiency, causing combined immunodeficiency. Therefore, patients with 18q deletion syndrome should be regularly tested for cellular/humoral immunocompetence., (© 2024. The Author(s).)

Phelan-McDermid syndrome (PMDS) arises from mutations in the terminal region of chromosome 22q13, impacting the SHANK3 gene. The resulting deficiency of the postsynaptic density scaffolding protein SHANK3 is associated with autism spectrum disorder (ASD). We examined 12 different PMDS patient and CRISPR-engineered stem cell-derived neuronal models and controls and found that reduced expression of SHANK3 leads to neuronal hyperdifferentiation, increased synapse formation, and decreased neuronal activity. We performed automated imaging-based screening of 7,120 target-annotated small molecules and identified three compounds that rescued SHANK3-dependent neuronal hyperdifferentiation. One compound, Benproperine, rescued the decreased colocalization of Actin Related Protein 2/3 Complex Subunit 2 (ARPC2) with ß-actin and rescued increased synapse formation in SHANK3 deficient neurons when administered early during differentiation. Neuronal activity was only mildly affected, highlighting Benproperine's effects as a neurodevelopmental modulator. This study demonstrates that small molecular compounds that reverse developmental phenotypes can be identified in human neuronal PMDS models., (© 2024. The Author(s).)

3p deletion syndrome or deletion 3p25-pter syndrome is an exceptionally rare genetic disorder characterized by deletion of the distal segment of the short arm of chromosome 3. There are less than a hundred reported cases worldwide. Clinical characteristics include severe physical and mental retardation, trigonocephaly, micrognathia, and diffuse hypotonia. The common ocular manifestations include congenital ptosis and canthal anomalies. To the best of the authors' knowledge, no lacrimal drainage anomalies have been reported earlier. The present case describes proximal lacrimal drainage anomalies in a patient with 3p deletion syndrome. The patient was successfully managed with membranotomy and punctal and canalicular dilatation, resulting in a complete resolution of epiphora.

Purpose: This study aims to evaluate the prevalence of submicroscopic chromosomal abnormalities found on single nucleotide polymorphism array (SNP array) in pregnancies with either an absent or hypoplastic nasal bone., Methods: This retrospective study included 333 fetuses with either nasal bone hypoplasia or absence identified on prenatal ultrasound. SNP array analysis and conventional karyotyping were performed in all the subjects. The prevalence of chromosomal abnormalities was adjusted for maternal age and other ultrasound findings. Fetuses with either an isolated nasal bone absence or hypoplasia, those that had additional soft ultrasound markers, and those where structural defects were found on ultrasound were divided into three groups: A, B, and C, respectively., Results: Among the total cohort of 333 fetuses, 76 (22.8%) had chromosomal abnormalities, including 47 cases of trisomy 21, 4 cases of trisomy 18, 5 cases of sex chromosome aneuploidy, and 20 cases of copy number variations of which 12 were pathogenic or likely pathogenic. The prevalence of chromosomal abnormalities in group A (n = 164), B (n = 79), and C (n = 90) was 8.5%, 29.1% and 43.3%, respectively. The incremental yields by SNP-array compared with karyotyping in group A, B, and C were 3.0%, 2.5% and 10.7%, respectively (p > 0.05). Compared to karyotype analysis, SNP array detected an additional 2 (1.2%), 1 (1.3%), and 5 (5.6%) pathogenic or likely pathogenic CNVs in groups A, B, and C, respectively. In the 333 fetuses, the prevalence of chromosomal abnormalities in women with advanced maternal age (AMA) was significantly higher than that in non-AMA women, (47.8% vs. 16.5%, p < 0.05)., Conclusion: In addition to Down's syndrome, many other chromosomal abnormalities are present in fetuses with abnormal nasal bone. SNP array can improve the prevalence of chromosomal abnormalities associated with nasal bone abnormalities, especially in pregnancies with non-isolated nasal bone abnormalities and advanced maternal age., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Phelan-McDermid syndrome (PMS) is a genetic neurodevelopmental disorder caused by SHANK3 haploinsufficiency and is associated with an increased risk for seizures. Previous literature indicates that around one third of individuals with PMS also have epilepsy or seizures, with a wide range of types and ages of onset. Investigating the impact of seizures on intellectual and adaptive functioning for PMS is a primary concern for caregivers and is important to understanding the natural history of this syndrome., Methods: We report on results from 98 individuals enrolled in a prospective, longitudinal study. We detailed seizure frequency, type, and age of onset, and we analyzed seizure occurrence with best estimate IQ, adaptive functioning, clinical features, and genotype. We conducted multiple linear regression analyses to assess the relationship between the presence of seizures and the Vineland Adaptive Behavior Scale, Second Edition (VABS-II) Adaptive Behavior Composite score and the best estimate full-scale IQ. We also performed Chi-square tests to explore associations between seizure prevalence and genetic groupings. Finally, we performed Chi-square tests and t-tests to explore the relationship between seizures and demographic features, features that manifest in infancy, and medical features., Results: Seizures were present in 41% of the cohort, and age of onset was widely variable. The presence of seizures was associated with significantly lower adaptive and intellectual functioning. Genotype-phenotype analyses were discrepant, with no differences in seizure prevalence across genetic classes, but with more genes included in deletions of participants with 22q13 deletions and seizures compared to those with 22q13 deletions and no seizures. No clinical associations were found between the presence of seizures and sex, history of pre- or neonatal complications, early infancy, or medical features. In this cohort, generalized seizures were associated with developmental regression, which is a top concern for PMS caregivers., Conclusions: These results begin to eludicate correlates of seizures in individuals with PMS and highlight the importance of early seizure management. Importantly, presence of seizures was associated with adaptive and cognitive functioning. A larger cohort might be able to identify additional associations with medical features. Genetic findings suggest an increased capability to realize genotype-phenotype relationships when deletion size is taken into account., (© 2024. The Author(s).)

Objective: To explore the genetic characteristics of a child with comorbid 16p11.2 microdeletion syndrome and Rett syndrome (RTT)., Methods: A male infant who was admitted to Gansu Provincial Maternity and Child Health Care Hospital in May 2020 was selected as the study subject. Clinical data of the infant was collected. Genomic DNA was extracted from peripheral blood samples from the infant and his parents, and subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing., Results: The patient, a 4-day-old male infant, had presented with poor response, poor intake, feeding difficulties, and deceased at 8 months after birth. WES revealed that he has harbored a 0.643 Mb deletion in the 16p11.2 region, which encompassed key genes of the 16p11.2 microdeletion syndrome such as ALDOA, CORO1A, KIFF22, PRRT2 and TBX6. His father has carried the same deletion, but was phenotypically normal. The deletion was predicted to be pathogenic. The child was also found to harbor a maternally derived c.763C>T (p.R255X) hemizygous variant of the MECP2 gene, which was also predicted to be pathogenic (PVS1+PS4+PM2&#95;Supporting)., Conclusion: The 16p11.2 deletion and the MECP2: c.763C>T (p.R255X) variant probably underlay the pathogenesis in this infant.

Objective: To explore the characteristics of a fetus with chromosome 1p36 deletion syndrome and 3p26.3p25.2 duplication., Methods: A pregnant woman who had attended the Genetic Counseling Clinic of Linyi People's Hospital on February 22, 2022 and her fetus were selected as the study subjects. Clinical data were collected. Chromosomal karyotyping, fluorescence in situ hybridization (FISH) and chromosomal microarray analysis (CMA) were carried out for the prenatal diagnosis., Results: Ultrasonography at 24th gestational week revealed that the fetus had ventricular septal defect, single umbilical artery, and slight widening of left lateral ventricle (12 mm). The woman was found to have a karyotype of 46,XX,t(1;3)(p36.22;p25.2), and the result of FISH was t(1;3)(3pter+,1qter+;1pter+,3qter+). The fetus was found to have a karyotype of 46,X?,add(1)(p36), and CMA confirmed that it has a 9.0 Mb deletion at 1p36.33p36.22 and a 12.6 Mb duplication at 3p26.3p25.2. Combining the maternal karyotype, the molecular karyotype of the fetus was determined as 46,X?,der(1)t(1;3)(p36.22;p25.2)mat.arr[hg19]1p36.33p36.22(849467&#95;9882666)×1, 3p26.3p25.2(61892&#95;12699607)×3, with the former known to be associated with 1p36 deletion syndrome., Conclusion: The fetus was diagnosed with 1p36 deletion syndrome, and its 1p36.33p36.22 deletion and 3p26.3p25.2 duplication had both derived from the balanced translocation carried by its mother.

Objective: The prenatal diagnosis of chromosomal mosaicism is fraught with uncertainty. Karyotyping, chromosomal microarray analysis (CMA), and fluorescence in situ hybridization (FISH) are three commonly used techniques. In this study, we evaluated these techniques for the prenatal diagnosis of chromosomal mosaicism and its clinical outcome., Study Design: A retrospective review of mosaicism was conducted in 18,369 pregnant women from January 2016 to November 2021. The subjects underwent amniocentesis to obtain amniotic fluid for G-band karyotyping with or without CMA/FISH. Cases diagnosed with chromosomal mosaicism were selected for further analysis., Results: In total, 101 cases of chromosomal mosaicism were detected in 100 pregnant women (0.54%, 100/18,369). Four were lost during follow-up, 61 opted to terminate their pregnancy, and 35 gave birth to a healthy singleton or twins. Among these 35 cases, postnatal cytogenetic testing was performed on eight and two exhibited mosaicism; however, nothing abnormal was observed in the postnatal phenotype follow-up. Karyotyping identified 96 incidents of chromosomal mosaicism including 13 with level II mosaicism and 83 with level III mosaicism, FISH identified 37 cases of mosaicism, and CMA identified 17. The most common form of chromosomal mosaicism involved monosomy X, of which the mosaic fraction in cultured karyotyping appeared higher or comparable to uncultured FISH/CMA ( p  < 0.05). Discordant mosaic results were observed in 34 of 101 cases (33.7%), most of which resulted from the detection limit of different techniques and/or the dominant growth of a certain cell line., Conclusion: Based on the postnatal follow-up results from the babies born, we obtained a more hopeful result for the prognosis of chromosomal mosaicism. Although karyotyping was the most sensitive method for detecting chromosomal mosaicism, artifacts and bias resulting from culture should be considered, particularly for sex chromosomal abnormalities involving X monosomy, in which the combination with uncultured FISH was necessary., Key Points: · Karyotyping combined with uncultured FISH or CMA is beneficial for prenatal diagnosis of chromosomal mosaicism.. · Fetuses without ultrasound structural anomalies with chromosomal mosaicism often have optimistic prognosis.., Competing Interests: None declared., (Thieme. All rights reserved.)

The rare genetic variants 16p11.2 duplication and 16p11.2 deletion have opposing effects on brain structure and function, yet are associated with broadly similar clinical phenotypes that include autism, intellectual impairment, psychiatric illness, and motor difficulties. In recent years, studies have identified subtle distinctions between the phenotypic effects of 16p11.2 duplication and 16p11.2 deletion with respect to patterns of autism, intellectual impairment, and psychiatric illness. However, although divergent phenotypic findings in some motor domains have been reported, no study has yet made a comprehensive comparison of motor difficulties between 16p11.2 deletion and 16p11.2 duplication carriers to elucidate points of convergence and divergence. We sought to make such a comparison in a group of 133 16p11.2 deletion carriers, 122 duplication carriers, and 388 familial controls, hypothesizing that motor impairment would overall be greater in deletion than duplication carriers. In a series of regression models, we found that 16p11.2 deletion status tended to predict greater impairment along indices of gross motor function, but less impairment along indices of fine motor function. These findings point to a potential pattern of performance difficulties that could be investigated in future studies. Elucidating motor differences between 16p11.2 duplication and 16p11.2 deletion carriers may help in understanding the complex effect of 16p11.2 copy number variation and other rare genetic causes of autism., (© 2024 International Society for Autism Research and Wiley Periodicals LLC.)

Genome-wide prenatal cell-free DNA (cfDNA) screening can be used to screen for a wide range of fetal chromosomal anomalies in pregnant patients. In this study, we describe our clinical experience with a genome-wide cfDNA assay in screening for common trisomies, sex chromosomal aneuploidies (SCAs), rare autosomal aneuploidies (RAAs), and copy-number variations (CNVs) in about 6000 patients over a three-year period at our hospital's Prenatal Diagnostic Unit in Spain. Overall, 204 (3.3%) patients had a high-risk call, which included 76 trisomy 21, 21 trisomy 18, 7 trisomy 13, 29 SCAs, 31 RAAs, 31 CNVs, and 9 cases with multiple anomalies. The diagnostic outcomes were obtained for the high-risk cases when available, allowing for the calculation of positive predictive values (PPVs). Calculated PPVs were 95.9% for trisomy 21, 77.8% for trisomy 18, 66.7% for trisomy 13, 10.7% for RAAs, and 10.7% for CNVs. Pregnancy and birth outcomes were also collected for the majority of RAA and CNV cases. Adverse perinatal outcomes for some of these cases included preeclampsia, fetal growth restriction, preterm birth, reduced birth weight, and major congenital structural abnormalities. In conclusion, our study showed strong performance for genome-wide cfDNA screening in a large cohort of pregnancy patients in Spain.

18p deletion syndrome constitutes one of the most frequent autosomal terminal deletion syndromes, affecting one in 50,000 live births. The syndrome has un-specific clinical features which vary significantly between patients and may overlap with other genetic conditions. Its prenatal description is extremely rare as the fetal phenotype is often not present during pregnancy. Trisomy 8p Syndrome is characterized by heterogenous phenotype, with the most frequent components to be cardiac malformation, developmental and intellectual delay. Its prenatal diagnosis is very rare due to the unspecific sonographic features of the affected fetuses. We present a very rare case of a fetus with multiple anomalies diagnosed during the second trimester whose genomic analysis revealed a 18p Deletion and 8p trisomy Syndrome. This is the first case where this combination of DNA mutations has been described prenatally and the second case in general. The presentation of this case, as well as the detailed review of all described cases, aim to expand the existing knowledge regarding this rare condition facilitating its diagnosis in the future., (© 2024. The Author(s).)

Background: Copy number variation sequencing (CNV-seq) is crucial in prenatal diagnosis, but its limitations in detecting polyploidy, maternal cell contamination (MCC), and uniparental disomy (UPD) restrict its application in the analysis of products of conception (POCs). This study aimed to investigate an optimal genetic testing strategy for POCs in the era of CNV-seq., Methods: CNV-seq and quantitative fluorescent polymerase chain reaction (QF-PCR) were performed in all 4,211 spontaneous miscarriage cases. Different testing strategies were compared and the optimal testing strategies were proposed., Results: Of the 4,211 cases, 2561 (60.82%) exhibited clinically significant chromosomal abnormalities. CNV-seq alone, without QF-PCR, might misdiagnose 311 (7.39%) cases, including 278 polyploidy, 13 UPD, and 20 MCC. In 20 MCC cases identified by QF-PCR, CNV-seq successfully pinpointed the cause of miscarriage in 13 cases. Furthermore, in cases where QF-PCR suggested polyploidy, CNV-seq improved the diagnostic accuracy in 54 (1.28%) hypo/hypertriploidy cases. After comparing four different strategies, the sequential approach (initiating with CNV-seq followed by QF-PCR if necessary) emerged as advantageous, reducing approximately 70% of the cost associated with QF-PCR while maintaining result accuracy., Conclusions: We propose an initial CNV-seq followed by QF-PCR if needed-an efficient and cost-effective strategy for the genetic analysis of POCs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)