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Marinesco-Sjögren syndrome(MSS) is a rare autosomal recessive inherited disease characterized by cerebellar ataxia, early-onset cataracts, chronic myopathy, and intellectual disability and developmental delay at varied degrees. Some patients may manifest such symptoms as short stature, hypergonadotropic hypogonadism, various skeletal abnormalities resulted from the muscular weakness, and others. This article reports the clinical and molecular diagnosis process of two MSS cases with global developmental delay. We found the compound heterozygous variants c.109delG(p.Glu37Serfs*4)and c.353G > C (p.Arg118Thr), c.443delA(p.Lys148Argfs*10)and c.707A > G (p.Asn236Ser) by Trio-whole exome sequencing(Trio-WES)which are evaluated as pathogenic, and uncertain significant, pathogenic and likely pathogenic variants separately.We provided genetic consultation based on the molecular diagnosis and evaluated the risk for the offsprings in the families. By introducing the two cases and literature review, this article aims at improving the understanding of MSS and providing reference to the diagnosis of the disease.

Primary ciliary dyskinesia (PCD) is a rare monogenic disorder primarily associated with structural and functional abnormalities of motile cilia. It is typically inherited in an autosomal recessive pattern. The disease affects multiple organs, and the variability in clinical phenotypes, along with genetic heterogeneity significantly complicates its diagnosis. Although the application of clinical exome sequencing has significantly improved the diagnostic rate of PCD, more than 30% of patients are still unable to obtain a definitive diagnosis. This article reviews and discusses the pathogenesis, diagnostic methods, and expanding genetic diagnostic approaches for patients with PCD that are negative for exome sequencing. The aim of this article is to assist clinicians in selecting more advanced emerging genetic testing technologies, with the hope of increasing the positive diagnostic rate of PCD, deepening the understanding of its genetic pathogenesis, and laying a foundation for the practice of gene therapy in the future.

AIM: The whole exome from the peripheral blood of 19 patients with aplastic anemia was sequenced, and the type and rate of gene mutation were observed to explore the pathogenesis of aplastic anemia. METHODS: Peripheral blood samples from 19 patients with aplastic anemia were collected, and mononuclear cells were extracted for whole exome sequencing. Enrichment analyses of the obtained genes were conducted using Gene Ontology （GO） and Kyoto Encyclopedia of Genes and Genomes （KEGG）. Data were statistically analyzed using IBM SPSS version 22. 0, and P<0. 05 indicated statistically significant differences. RESULTS: Overall, 2 006 gene mutations were identified in 19 patients with aplastic anemia, and 49 genes were selected based on GeneCards and OMIM databases and sequencing results. A gene mutation map of the patient was drawn, which revealed a potential association of MUC5B gene with the onset of aplastic anemia, with a mutation rate of 100%. Other genes, such as ERCC6, SYNE1 and WFS1, have mutation rates exceeding 40% and may be involved in the development of aplastic anemia. In GO analysis, it was mainly related to cell movement, cytoskeleton composition, protein binding, and other functions. In the KEGG pathway analysis, the Hippo pathway and the extracellular matrix-receptor interaction pathway were the main enrichment areas. CONCLUSION: MUC5B may be a key gene that causes T cell imbalance, leading to aplastic anemia. The Hippo pathway may also participate in the pathogenesis of aplastic anemia through regulatory T cells and telomerase activity. [ABSTRACT FROM AUTHOR]

This article reported four cases of sebaceous gland carcinoma of the eyelid with other tumors. Among them, three cases were co-occurred with other ocular tumors, two cases with visceral malignancies, and one case with chronic lymphocytic leukemia/small lymphocytic lymphoma. Immunohistochemistry and/or whole-exome sequencing confirmed that the two cases with visceral malignancies did not meet the criteria for Muir-Torre syndrome. Additionally, whole-exome sequencing was performed on two cases of sebaceous gland carcinoma of the eyelid, both revealing mutations in the ZNF750 gene. Surgical interventions included excision of the eyelid tumors in three cases and enucleation of orbital tissues and eye removal in one case. Follow-up results showed no recurrence in two cases with eyelid tumors and one case with orbital invasion, while one patient died due to peritoneal metastasis from ovarian cancer.

Objective: To explore the genetic etiology of a pedigree with intellectual disability and explore its pathogenesis., Methods: A Chinese pedigree which had presented at the Henan Provincial People's Hospital in March 2023 was selected as the study subject. Clinical data of the pedigree were collected, along with peripheral venous blood samples from its members. Whole exome sequencing (WES) was carried out, and candidate variants were verified by Sanger sequencing. Amniotic fluid was collected for prenatal diagnosis. This study was approved by the Medical Ethics Committee of the Henan Provincial People's Hospital (Ethics No. 2019-134)., Results: Both the proband (a 6-year-old male) and his mother (30 years old) had various degrees of intellectual and motor impairment. WES revealed that the proband has harbored a de novo heterozygous c.2563&#95;2567dup (p.Lys856fs) variant of the UBE3A gene, while his mother, maternal grandmother and fetus had all harbored a novel heterozygous c.409+1G>A variant of the RNF13 gene. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were predicted to be pathogenic (PVS1+PS1+PM2&#95;Supporting; PVS1+PM2&#95;Supporting+PP3)., Conclusion: Based on the clinical manifestations and the result of genetic testing, the heterozygous c.2563&#95;2567dup (p.Lys856fs) variant of the UBE3A gene probably underlay the intellectual disability and developmental delay in the proband, whilst the heterozygous c.409+1G>A variant of the RNF13 gene may underlie the intellectual disability in the proband's mother and grandmother. Above results have enabled genetic counseling and prenatal diagnosis for this pedigree.

Objective: To explore the genetic etiology and clinical phenotype of a child with Triadin knockout syndrome (TKOS), and to review the relevant literature of TKOS patients due to variants of TRDN gene., Methods: A child who was admitted to the Children's Hospital of Xi'an Jiaotong University on March 19, 2023 due to sudden cardiac arrest 3 days earlier was selected as the study subject. Peripheral blood samples (2 to 3 mL) were collected from the child and her parents for the extraction of genomic DNA and whole exome sequencing (WES). Pathogenic variants were searched from databases such as the Genome Aggregation Database (gnomAD) and Online Mendelian Inheritance in Man (OMIM), and were assessed based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). Sanger sequencing was carried out for family validation of the pathogenic variants. Using keywords such as "arrhythmias" "TRDN" and "Triadin" both in Chinese and English, relevant literature on TKOS patients due to variants of the TRDN gene was retrieved from the CNKI, Wanfang Data Knowledge Service Platform, and PubMed databases, and the time of literature retrieval was set from January 1, 2012 to December 1, 2023. This study has been approved by the Ethics Committee of the Affiliated Children's Hospital of Xi'an Jiaotong University (No. 20230097), and informed consent was obtained from the parents of the child., Results: The child had experienced syncope and cardiac arrest after exercise. Electrocardiographic examination revealed QTc interval prolongation, T-wave inversion in precordial leads V1-V3, polymorphic ventricular premature beat (VPB), and ventricular tachycardia (VT) along with increased heart rate. WES and Sanger sequencing revealed that the child has harbored a homozygous c.463del(p.E155Kfs*20) variant of the TRDN gene, for which both of the parents were heterozygous. Based on the guidelines from the ACMG, the variant was classified as pathogenic (PVS1+PM2+PM3). The child was ultimately diagnosed with TKOS. In total 12 publications on TOKS cases caused by TRDN gene variants were retrieved, which involved 30 patients and 28 carriers of single heterozygous variant of the TRDN gene. Among the 30 TKOS patients, 20 had carried homozygous variants of the TRDN gene, and 10 had carried compound heterozygous variants, and all had exhibited significant clinical phenotype of arrhythmia, with most cases had experienced malignant arrhythmia induced by exercise and/or excitement during infancy or early childhood, leading to recurrent syncope and cardiac arrest. Of note, none of the 28 carriers of single heterozygous variant had abnormal clinical phenotype., Conclusion: The homozygous c.463del(p.E155Kfs20) variant of the TRDN gene probably underlay the pathogenesis of cardiac arrest in this child. Above discovery has enriched the mutational spectrum of the TRDN gene.

Objective: To analyze the clinical characteristics of a child with Congenital disorder of glycosylation due to compound heterozygous variants of COG6 gene (COG6-CDG)., Methods: A child who was admitted to Xi'an Children's Hospital on January 10, 2023 was selected as the study subject. Clinical data were collected. Pathogenic variants were analyzed by whole exome sequencing, and candidate variants were verified by Sanger sequencing, in vitro experiments and bioinformatic analysis. This study was approved by the Medical Ethics Committee of Xi'an Children's Hospital (Ethics No. 20230101)., Results: The child, a 1-month-8-day-old male, was admitted for diarrhea and weight loss for one month. He had presented with cholestasis, diarrhea, facial dysmorphism, poor response, bilateral Simian crease, and brain atrophy. After discharge, he had continued to have high fever, feeding difficulty, and deceased finally. Whole exome sequencing results showed that he had harbored compound heterozygous variants of the COG6 gene, namely c.807delT (p.F269Lfs*37) and c.1746+1G>C (p.Gly565&#95;Met582del). Sanger sequencing verified that the variants were inherited from his father and mother, respectively. In vitro experiments verified that the c.1746+1G>C variant could affect the mRNA splicing and produce a truncated protein, whilst the c.807delT variant could significantly reduce gene expression at both mRNA and protein levels. Based on the guidelines from the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG-AMP), the variants were classified as pathogenic (PVS1+PM3+PM2&#95;Supporting) and likely pathogenic (PVS1+PM2&#95;Supporting), respectively., Conclusion: The c.807delT (p.F269Lfs*37) and c.1746+1G>C (p.Gly565&#95;Met582del) compound heterozygous variants of the COG6 gene probably underlay the pathogenesis of this child. Above finding has enriched the mutational spectrum of COG6-CDG and provided a basis for the genetic counseling for this family.

Objective: To explore the genetic etiology of a child featuring multiple fractures and congenital insensitivity to pain (CIP)., Methods: A child who had presented at the West China Hospital of Sichuan University on March 16, 2023 for recurrent fractures and CIP was selected as the study subject. Peripheral blood samples of the child and his parents was collected. Trio-whole exome sequencing was carried out. Candidate variants were verified by Sanger sequencing and bioinformatic analysis. This study has been approved by the Medical Ethics Committee of West China Hospital of Sichuan University (No. 2019-772)., Results: Trio-whole exome sequencing revealed that the child has harbored compound heterozygous variants of the SCN9A gene, namely c.560delC (p.P187Rfs*15) and c.829C>T (p.R277*), which were respectively inherited from his father and mother. Homozygous c.829C>T variant had been demonstrated as pathogenic among CIP patients, whilst the c.560delC (p.P187Rfs*15) variant was unreported previously and predicted to be pathogenic based on the guidelines of the American College of Medical Genetics and Genomics (ACMG)., Conclusion: The child was diagnosed with CIP due to the compound heterozygous variants of the SCN9A gene. Above finding has enabled genetic counselling and reproductive guidance for this family.

Objective: To explore the clinical phenotype and genetic characteristics of a patient with Ataxia and vitamin E deficiency syndrome (AVED) due to a variant of TTPA gene., Methods: A patient diagnosed with AVED (proband), intended for assisted reproductive technology for pregnancy in Zhongnan Hospital of Wuhan University in July 2023, was selected as research subject. Clinical data of the proband were collected, and 2 mL of peripheral venous blood samples were collected from the proband and her father and siblings for serum vitamin E level testing. Whole exome sequencing (WES) was carried out. Pathogenic variants were selected based on American public archive of interpretations of clinically relevant variants (ClinVar). Sanger sequencing was performed to validate the candidate variants detected by WES. Pathogenicity of variants was classified based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), and the impact of variants was analyzed using multiple bioinformatics tools including SIFT, Mutation Taster, CADD, and SpliceAI. Information on the protein domains was obtained from ClinVar and dbSNP databases, and a hotspot map for the variants of protein-coding region was constructed. This study was approved by the Medical Ethics Committee of Zhongnan Hospital of Wuhan University (No. 2023068K)., Results: The proband has a significantly low serum level of vitamin E (5.186 μg/mL), while her father and siblings were normal. WES revealed that she has harbored a homozygous missense c.2T>A (p.0?) variant of the TTPA gene, for which her father and younger sister were heterozygous carriers. Based on the guidelines from the ACMG, the missense c.2T>A (p.0?) variant of the TTPA gene was classified as pathogenic (PVS1+PM2+PM3). Multiple bioinformatics tools had predicted this variant to be located in the initiation codon region and may lead to abnormal synthesis of the TTPA protein, indicating it was deleterious. The hotspot map based on ClinVar and dbSNP databases showed an even distribution of variants across 5 structural domains of the TTPA protein, with high conservation of the first amino acid residue across various species., Conclusion: The homozygous c.2T>A (p.0?) variant of the TTPA gene probably underlie the AVED in the proband. Above discovery has enriched the mutational spectrum of AVED and provided a basis for the diagnosis, genetic counseling, and assisted reproductive strategies for this family.

Objective: To summarize the clinical manifestations of Autosomal dominant complex neurodevelopmental disorders due to variants of EEF1A2 gene and explore their pathogenic mechanisms., Methods: A child who had visited Luoyang Maternal and Child Health Care Hospital in July 2021 for global developmental delay was selected as the study subject. Clinical data of the child was reviewed. The child was subjected to whole exome sequencing, and relevant literature was reviewed. This study has been approved by the Medical Ethics Committee of Luoyang Maternal and Child Health Care Hospital (No. YCCZ-KS-KY-2021-03)., Results: The patient, a 2-year-and-4-month-old girl, had presented with global developmental delay, gait instability, low limb muscle strength, and absence language development. Her parents were both healthy and denied relevant family history. Genetic testing revealed that she has harbored a de novo heterozygous c.44A>G (p.H15R) missense variant of the EEF1A2 gene (NM&#95;001958.5), which was unreported previously. Based on the guidelines from the American College of Medical Genetics and Genomics, the variant was rated as pathogenic., Conclusion: The c.44A>G (p.H15R) variant of the EEF1A2 gene probably underlay the pathogenesis in this patient. Above finding has also enriched the mutational spectrum of the EEF1A2 gene.

Objective: To determine the carrier frequency and hot-spot variants of a custom-designed expanded carrier screening (ECS) panel with 216 diseases (216-ECS panel) within a Chinese population of childbearing age. Methods: Whole-exome sequencing data from a cohort of 3 097 unrelated healthy individuals (including 1 424 couples) from Peking Union Medical College Hospital between January 2013 and December 2023 were analyzed. Totally 220 genes which inherited in a recessive manner of 216-ECS panel were included in the analysis. The analysis included variant carrier rate, gene carrier rate, cumulative carrier rate, at-risk couple rates, and variant spectrum. Results: (1) Pathogenic variants were identified in 1 472 (47.53%, 1 472/3 097) individuals, with an average of 0.65 pathogenic variants per individual. The rate of at-risk couples was 3.93% (56/1 424). (2) A total of 180 genes were identified, with 16 genes exhibiting a gene carrier rate of ≥1% and 33 genes having a rate of ≥0.5%, most of which were associated with inherited metabolic diseases. Noteworthy genes with higher gene carrier rates and high-frequency variants included GJB2 : c.235del, PAH : c.728G>A, ATP7B : c.2333G>T, SLC26A4 : c.919-2A>G, GALC : c.1901T>C, POLG : c.2890C>T, SLC22A5 : c.1472C>G, USH2A : c.2802T>G, SLC25A13 : c.852&#95;855del, GAA : c.761C>T and c.752C>T. Conclusion: This study offers a focused analysis of carrier frequencies and hot-spot variants of 216 diseases of the ECS panel constructed by our laboratory among the Chinese population, laying a foundation for the development of ECS programs tailored to the Chinese population.

Objective: To analyze and clarify the clinical and pathogenic gene variation and genetic etiology of polycystic liver disease. Methods: The proband clinical data and family history were collected. Whole-exome sequencing technology was used to detect the proband gene variations. Fluorescence quantitative PCR validation was performed on the proband and his family to screen out pathogenic gene variation. Results: A multiple liver cyst was found in an 18-year-old male proband during a physical examination. There were no abnormalities in his liver function, and both his father and grandfather had multiple liver cysts without any obvious discomfort or other special manifestations. Whole exome sequencing suggested a heterozygous deletion in exon 1 (Exon 1) of the SEC63 gene in the proband. Real-time fluorescence quantitative PCR confirmed that the heterozygous deletion variation of the SEC63 gene Exon 1 of the proband came from his father, and the same heterozygous deletion was detected in his grandfather. The gene variant had a pathogenic variation that had been rarely reported before and was in accordance with the the American college of Medical Genetics and Genomics (ACMG) guidelines. Conclusions: The genetic etiology of this autosomal dominant polycystic liver disease has been clarified, and the heterozygous deletion of Exon1 of the SEC63 gene is a newly discovered gene variation that broadens the variation spectrum of the SEC63 gene.

Objective: To detect the cystic fibrosis transmembrane transduction regulator ( CFTR ) gene mutations and congenital bilateral absence of vas deferens (CBAVD) susceptibility gene mutations in patients with CBAVD, and to explore their association with the risk of CBAVD., Methods: Whole-exome sequencing and Sanger sequencing validation were conducted on the pathogenic genes CFTR , adhesion G protein-coupled receptor G2 ( ADGRG2 ), sodium channel epithelial 1 subunit beta ( SCNN1B ), carbonic anhydrase 12 ( CA12 ), and solute carrier family 9 member A3 ( SLC9A3 ) in thirteen cases of isolated CBAVD patients. The polymorphic loci, intron and flanking sequences of CFTR gene were amplified by polymerase chain reaction (PCR) followed by Sanger sequencing. Bioinformatics methods were employed for conservative analysis and deleterious prediction of novel susceptibility gene mutations in CBAVD. Genetic analysis was performed on the pedigree of one out of thirteen patients with CBAVD to evaluate the risk of inheritance in offspring., Results: Exome sequencing revealed CFTR gene exon mutations in only six of the thirteen CBAVD patients, with six missense mutations c.2684G>A(p.Ser895Asn), c.4056G>C(p.Gln1352His), c.2812G>(p.Val938Leu), c.3068T>G(p.Ile1023Arg), c.374T>C(p.Ile125Thr), c.1666A>G(p.Ile556Val)), and one nonsense mutation (c.1657C>T(p.Arg553Ter). Among these six patients, two also had the CFTR homozygous p.V470 site, additionally, mutations in CFTR gene exon regions were not detected in the remaining seven patients. Within the thirteen CBAVD patients, three carried the homozygous p.V470 polymorphic site, four carried the 5T allele, two carried the TG13 allele, and ten carried the c.-966T>G site. Four CBAVD patients simultaneously carried 2-3 of the aforementioned CFTR gene mutation sites. Susceptibility gene mutations in CBAVD among the thirteen patients included one ADGRG2 missense mutation c.2312A>G(p.Asn771Ser), two SLC9A3 missense mutations c.2395T>C(p.Cys799Arg), c.493G>A(p.Val165Ile), one SCNN1B missense mutation c.1514G>A(p.Arg505His), and one CA12 missense mutation c.1061C>T (p.Ala354Val). Notably, the SLC9A3 gene c.493G>A (p.Val165Ile) mutation site was first identified in CBAVD patients. The five mutations exhibited an extremely low population mutation frequency in the gnomAD database, classifying them as rare mutations. Predictions from Mutation Taster and Polyphen-2 software indicated that the harmfulness level of the SLC9A3 gene c.493G>A (p.Val165Ile) site and the SCNN1B gene c.1514G>A (p.Arg505His) site were disease causing and probably damaging. The genetic analysis of one pedigree revealed that the c.1657C>T (p.Arg553Ter) mutation in the proband was a de novo mutation, as neither the proband's father nor mother carried this mutation. The proband and his spouse conceived a daughter through assisted reproductive technology, and the daughter inherited the proband's pathogenic mutation c.1657C>T (p.Arg553Ter)., Conclusion: CFTR gene mutations remain the leading cause of CBAVD in Chinese patients; however, the distribution and frequency of mutations differ from data reported in other domestic and international studies, highlighting the need to expand the CFTR mutation spectrum in Chinese CBAVD patients. The susceptibility genes ADGRG2 , SLC9A3 , SCNN1B , and CA12 may explain some cases of CBAVD without CFTR mutations. Given the lack of specific clinical manifestations in CBAVD patients, it is recommended that clinicians conduct further physical examinations and consider scrotal or transrectal ultrasound before making a defi-nitive diagnosis. It is advisable to employ CFTR gene mutation testing in preconception genetic screening to reduce the risk of CBAVD and cystic fibrosis in offspring.

Objective: To explore the clinical characteristics and genetic etiology of a child with Spondyloocular syndrome (SOS) in order to enhance the awareness and understanding of this disease., Methods: A 3.5-year-old boy with SOS who had presented at the Department of Medical Genetics of Hunan Children's Hospital on August 10, 2023 due to the repeated fractures for over 2 years and after binocular cataract surgery was selected as the study subject. Clinical data of his pedigree were collected, and peripheral venous blood samples were collected for the extraction of genomic DNA and subjected to trio-whole exome sequencing. Candidate variants were verified by Sanger sequencing and analyzed with bioinformatic software. This study was approved by the Medical Ethics Committee of Hunan Children's Hospital (Ethics No. KYAQ2022-263)., Results: The child had manifested repeated fractures, bilateral bowed femur, osteoporosis, cataract, atrial septal defect, and developmental delay. Ultrasonography has revealed fetal edema, peritoneal effusion, pleural effusion and polyhydramnios. Trio-whole exome sequencing and Sanger sequencing revealed that he has harbored compound heterozygous variants of the XYLT2 gene, namely c.1103&#95;1104delAG (p.Gln368Argfs*8) and c.1238&#95;1253delinsA (p.Val413&#95;Pro418delinsGlu), which were inherited from his phenotypically normal father and mother, respectively. Neither variant was reported previously. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG) and recommendations from the Clinical Genome Resource (ClinGen), the c.1103&#95;1104delAG was predicted as a pathogenic variant (PVS1+PM2&#95;Supporting+PP4), whilst the c.1238&#95;1253delinsA was predicted as a likely pathogenic variant (PM4+PM3+PM2&#95;Supporting+PP4)., Conclusion: The c.1103&#95;1104delAG and c.1238&#95;1253delinsA compound heterozygous variants of the XYLT2 gene probably underlay the pathogenesis in this child. Above finding has enriched the phenotypic and mutational spectrum of SOS, and provided a basis for the clinical diagnosis, treatment, prognosis assessment and genetic counseling for this pedigree.

Objetive: To explore the clinical manifestations and genetic etiology of a Chinese pedigree affected with Familial focal epilepsy with variable foci (FFEVF)., Methods: A FFEVF pedigree presented at the Department of Medical Genetics of Linyi Maternal and Child Health Care Hospital on March 14, 2023 was selected as the study subject. The proband was subjected to whole exome sequencing (WES). Candidate variants were verified by Sanger sequencing of the proband and other affected members and bioinformatic analysis. This study was approved by the Linyi Maternal and Child Health Care Hospital (Ethics No. QTL-YXLL-2023048)., Results: WES revealed that the proband has harbored a heterozygous c.1642C>T (p.Arg548Cys) missense variant in exon 15 of the NPRL3 gene. Sanger sequencing confirmed that the variant was inherited from the proband's father, and multiple members of the pedigree had also harbored the same variant. Based on guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as variant of unknown significance (PM2&#95;supporting + PP3)., Conclusion: The clinical phenotype of FFEVF patients caused by variants of NPRL3 gene is extensive, and the patients may present with neurological abnormality of autism spectrum disorder in addition to seizures.

Objective: To carry out genetic testing on a child diagnosed with Very-long-chain acyl-CoA dehydrogenase deficiency (VLADD) in order to provide a basis for genetic counseling and prenatal diagnosis for his family., Methods: Whole exome sequencing was performed for the proband. Candidate variant sites in the ACADVL gene were verified by Sanger sequencing, and their pathogenicity was predicted based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). Prenatal diagnosis was performed on the fetus upon subsequent pregnancy. This study was approved by the Luoyang Maternal and Child Health Care Hospital (Ethics No. )., Results: The proband was found to harbor compound heterozygous variants of the ACADVL gene, namely c.1532G>A and 1827+2&#95;1827+12del, which were inherited from his mother and father, and classified as likely pathogenic and pathogenic, respectively. By combining the clinical manifestations of the proband and the results of blood tandem mass spectrometry and genetic testing, the child was ultimately diagnosed as cardiomyopathy type VLADD. Prenatal diagnosis showed that the fetus has carried the same compound heterozygous variants, and the couple had opted to terminate the pregnancy., Conclusion: The c.1532G>A/1827+2&#95;1827+12del compound heterozygous variants of the ACADVL gene probably underlay the pathogenesis of VLADD in this pedigree. The discovery of the 1827+2&#95;1827+12del variant has enriched the mutational spectrum of the ACADVL gene.

Objetive: To explore the clinical and genetic etiology of a Chinese pedigree affected with type 2 Long QT syndrome (LQTS)., Methods: A pedigree with type 2 LQTS presented at Fuwai Central China Cardiovascular Hospital on August 23, 2019 was selected as the study subject. Peripheral blood samples were collected from the proband and her parents. Following extraction of genomic DNA, whole exome sequencing (WES) was carried out for the proband, and candidate variant was screened through functional annotation and protein-protein interaction (PPI) analysis. Sanger sequencing was conducted to verify the pathogenicity of candidate variant. This study was approved by the Fuwai Central China Cardiovascular Hospital (Ethics No. 2019-15)., Results: WES revealed that the proband has harbored a missense variant of the KCNH2 gene, namely c.1478A>G (p.Tyr493Cys), which was confirmed by Sanger sequencing to have inherited from her father. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as likely pathogenic (PM2&#95;supporting+PM5+PP3+PP4)., Conclusion: The KCNH2 gene c.1478A>G (p.Tyr493Cys) variant probably underlay the type 2 LQTS in this pedigree.

Objective: To explore the genetic etiology for a child with Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 6 (PEOA6)., Methods: A child who had attended the Women and Children's Hospital Affiliated to Ningbo University on 7 August, 2023 was selected as the study subject. Clinical data of the child were analyzed retrospectively. The child and her parents were subjected to whole exome sequencing (WES), and candidate variant was verified by Sanger sequencing and bioinformatic analysis. This study was approved by the Women and Children's Hospital Affiliated to Ningbo University (Ethics No. EC2020-048)., Results: The child, a 7-year-old female, had presented with limb muscle pain, amyosthenia, significantly increased creatine kinase, congenital diaphragmatic hernia and recurrent respiratory tract infections. WES revealed that the she has harbored a heterozygous c.1590G>C (p.L530F) variant of the DNA2 gene, which was verified to have a de novo origin by Sanger sequencing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.1590G>C was rated as a likely pathogenic variant (PS2+PM2&#95;Supporting+PP3)., Conclusion: The c.1590G>C (p.L530F) variant of the DNA2 gene probably underlay the PEOA6 in this child.

Objective: To explore the genetic etiology and clinical outcome of a child with co-morbid progressive IgA nephropathy and COQ8B-associated glomerulopathy., Methods: A child who was admitted to Peking University First Hospital on March 2, 2021 was selected as the study subject. Genomic DNA was extracted from peripheral blood samples from the child and his parents and sister. Whole exome sequencing was carried out, and candidate variant was verified by Sanger sequencing. This study was approved by the Peking University First Hospital (Ethics No. 2016[1029])., Results: The child, a 7-year-old boy who had developed proteinuria 8 months before, was diagnosed with IgA nephropathy (M1E1S1T1C1). With steroid, cyclophosphamide, cyclosporine and angiotensin-converting enzyme inhibitor therapy, partial remission of proteinuria was achieved. However, his serum creatinine level had increased from 53.8 mol/L at the onset of disease to 86.7 mol/L after 3.9 years, along with massive proteinuria. Kidney biopsy still indicated IgA nephropathy (M0E0S1T0C0). The child was found to harbor a homozygous c.737G>A (p.Ser246Asn) missense variant of the COQ8B gene, for which his parents and sister were heterozygous carriers. The variant was predicted to be pathogenic (PS1+PM2&#95;Supporting+PM3+PP3+PP4) based on the guidelines from the American College of Medical Genetics and Genomics. The child was treated with high-dose coenzyme Q10 in combination with steroid and/or mycophenolate mofetil, though his serum creatinine level still increased to 286 mol/L after 7.3 years, which conformed to a chronic kidney disorder with glomerular filtration rate category of G3b., Conclusion: The homozygous c.737G>A missense variants of the COQ8B gene probably underlay the progressive kidney dysfunction in this child. For children with IgA nephropathy presenting with atypical clinical manifestations, unsatisfactory therapeutic effect, and/or early onset of kidney function decline, coexistence of other diseases should be suspected.

Objetive: To explore the clinical and genetic characteristics of two children with Neurodevelopmental disorders (NDDs) due to variants of TANC2 gene., Methods: Clinical data of two children who were admitted to the Third Affiliated Hospital of Zhengzhou University respectively in April 2020 and April 2021 were retrospectively analyzed. Peripheral blood samples of the children and their parents were collected and subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing. By using "TANC2 gene", "Neurodevelopmental disorders", "Nervous system development disorders", "TANC2" as the key words, similar cases were searched from the CNKI, Wanfang database platform and PubMed database, with the search time set as from the establishment of the database to December 2023. This study was approved by the Third Affiliated Hospital of Zhengzhou University (Ethics No. 2020-57)., Results: Case 1 was a 1-year-and-3-month-old girl who had developed convulsions at 1 year old and had three episodes of seizures. Her epilepsy had resolved with the treatment of oxcarbazepine, which was stopped at the age of 2-year-and-7-month. Her language, movement and intelligence development were all normal. Case 2 was a 1-year-and-10-month-old boy, who had developed convulsions at 1 year old. His seizure type was myoclonus, and the frequency was dozens of times a day. His epilepsy had resolved with the treatment of sodium valproate. His language, movement and intelligence development was delayed for about half a year. Genetic analysis showed that both children had harbored novel variants of the TANC2 gene (NM&#95;025185.4), including c.3398G>A (p.Gly1133Glu) and c.2829+1G>A, respectively. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the former was rated as likely pathogenic (PS2+PM2&#95;Supporting+PP3) and the latter was rated as pathogenic (PVS1+PS2+PM2&#95;Supporting). Two previous reports were retrieved, which had involved 17 cases and 16 variants. Common features had included autism spectrum disorder (70.6%, 12/17) , intellectual disability (94.1%,16/17) , language and motor retardation (88.2%, 15/17；58.8%, 10/17), facial dysmorphism, epilepsy, ataxia, and thoracic and spinal deformities., Conclusion: Variants of the TANC2 gene probably underlay the epilepsy and development delay in these children with NDDs.

Objective: To explore the genetic etiology of a fetus with Coffin-Siris syndrome (CSS)., Methods: A fetus with abnormal ultrasound findings detected at Luoyang Maternal and Child Health Care Hospital in July 2023 was selected as the study subject. Clinical data were analyzed retrospectively. Whole exome sequencing was carried out on fetal tissue and parental peripheral blood samples, and candidate variant was verified by Sanger sequencing and pathogenicity analysis. This study was approved by the Luoyang Maternal and Child Health Care Hospital (Ethics No. LYFY-YCCZ-2023011)., Results: Color Doppler ultrasound at 16 + gestational weeks revealed bilateral ventriculomegaly and cerebellar hypoplasia in the fetus. Trio-WES found that the fetus has harbored a heterozygous c.553C>T (p.Gln185Ter) variant of the ARID1A gene, which was verified by Sanger sequencing to have a de novo origin. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.553C>T (p.Gln185Ter) variant of the ARID1A gene was classified as pathogenic (PVS1+PS2&#95;Supporting+PM2&#95;Supporting)., Conclusion: The fetus was diagnosed with CSS type 2, and the heterozygous c.553C>T (p.Gln185Ter) variant of the ARID1A gene probably underlay its brain malformations.

Objective: To explore the clinical characteristics and pathogenic variant in a child with Cantú syndrome (CS)., Methods: A male who was admitted to the Children's Hospital Affiliated to Zhengzhou University on February 23, 2022 was selected as the study subject. Clinical data of the child was collected. Peripheral blood samples of the child and his parents were collected and subjected to whole-exome sequencing (WES). Candidate variant was verified by Sanger sequencing. This study was approved by the Children's Hospital Affiliated to Zhengzhou University (Ethics No. 2023-K-087)., Results: The child, a 3-year-and-2-month-old male, was born with hirsutism, with heavy hair all over the body and peculiar facial features. Routine echocardiography 1 month before had discovered atrial septal defect. Sequencing revealed that the child has harbored a heterozygous c.2438G>C (p.S813T) variant of the ABCC9 gene, which was de novo in origin. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.2438G>C variant was classified as likely pathogenic (PS2+PM2&#95;Supporting+PP3)., Conclusion: The heterozygous c.2438G>C variant of the ABCC9 gene probably underlay the pathogenesis of CS in this child.

Objective: To explore the clinical and genetic characteristics of a child with autosomal recessive primary microcephaly (MCPH)., Methods: A case study has been carried out on a boy who had presented at the Inner Mongolia Maternity and Child Health Care Hospital for microcephaly and mental deficiency in September 2022. Prenatal ultrasound images were retrospectively analyzed, and whole exome sequencing and Sanger sequencing were carried out for his family. A literature review was also carried out using keywords such as "ASPM gene", "microcephaly", "prenatal diagnosis", "primary microcephaly", "ASPM", "MCPH5", "MCPH", "autosomal recessive microcephaly", and "prenatal diagnosis on ultrasonography" on the PubMed database, Wanfang Data and China National Knowledge until September 2023. This study was approved by the Inner Mongolia Maternity and Child Health Care Hospital (Ethics No. 2021-093-1)., Results: The proband had shown progressive reduction in biparietal diameter (BPD) and head circumference (HC) during the fetal period. He was found to harbor compound heterozygous variants of the ASPM gene, which included a paternally derived c.8044C>T (p.R2682X) and a maternally derived c.8652dup (p.A2885Sfs*35). Both variants were classified as pathogenic (PVS1+PM2&#95;Supporting+PP4; PVS1+PM2&#95;Supporting+PM3) based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). For other fetuses in his family, prenatal ultrasound and genetic testing were all normal. Literature research has identified 11 relevant articles, which included 14 MCPH cases. All of the MCPH5 cases had shown various degrees of reduced BPD/HC on fetal imaging (100%, 15/15). Developmental delay, intellectual disability, and attention deficits were noted in all survived cases, with one case having seizures (12.5%, 1/8). Their genotypes had included homozygotes (46.2%, 6/13) and compound heterozygotes (53.8%, 7/13) for nonsense variants (45%, 9/20) and frameshifting variants (55%, 11/20)., Conclusion: The compound heterozygous variants c.8044C>T (p.R2682X) and c.8652dup (p.A2885Sfs*35) of the ASPM gene probably underlay the reduced BPD and HC in this proband with MCPH.

Objectives: This study aimed to identifyPAX9variants in non-syndromic tooth agenesis families of China, as well as to analyze the genotype⁃phenotype of non-syndromic tooth agenesis caused by PAX9variants, which can provide a basis for the genetic diagnosis of tooth agenesis., Methods: We collected the data of 44 patients with non-syndromic oligodontia who underwent treatment at Stomatological Hospital of Hebei Medical University between 2018 and 2023. Whole-exome sequencing was performed on the peripheral blood of the proband and its core family members, and the variants were verified by Sanger sequencing. Pathogenicity analysis and function prediction of the variants were performed using bioinformatics tools. The correlation between the genotype of PAX9 variant and its corresponding phenotype was examined by reviewing 55 publications retrieved from PubMed. The studies involved 232 tooth agenesis patients with PAX9 variants., Results: A novel PAX9 c.447delG (p.Pro150Argfs*62) and a reported PAX9 c.406C>T (p.Gln136*) were identified in two Chinese families. Through bioinformatics analysis and three-dimensional structural modeling, we postulated that the frameshift variant was pathogenic. The outcome was the premature cessation of PAX9 protein, which caused severe structural and functional deficiencies. Summarizing the PAX9 genotype-phenotype relationship revealed that patients carrying the PAX9 variant commonly led to loss of the second molars., Conclusions: We identified the novel PAX9 c.447delG (p.Pro150Argfs*62) in a Chinese family of non-syndromic oligodontia, expanding the known variant spectrum of PAX9. The most susceptible tooth position for PAX9 variants of tooth agenesis was the second molars and the deciduous molars during the deciduous dentition.

Objective: To explore the clinical phenotype and genetic etiology for seven children with CHARGE syndrome (CS)., Methods: Clinical data of seven children with CS diagnosed between March 2020 and December 2022 at the Children's Hospital Affiliated to Zhengzhou University were analyzed. Genomic DNA was extracted from peripheral blood samples from the children and their parents, and subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing and pathogenicity analysis., Results: The ages of the children had ranged from 1 day after birth to 12 years old, and all of them had shown growth retardation. The reasons for their admission had included postnatal breathing, swallowing and feeding difficulties in five cases. One child was found to have abnormal external genitalia in conjunct with hearing impairment, whilst another child had shown no secondary sexual characteristics during puberty. All of the children were found to harbor CHD7 gene variants, which included 3 nonsense variants, 2 frameshifting variants and 2 missense variants, i.e., c.6292C>T (p.R2098*), c.2754G>A (p.W918*), c.469C>T (p.R157*), c.3308T>A (p.V1103D), c.7111delC (p.Q2371Kfs), c.6023delA (p.D2008Vfs) and c.3565C>T (p.R1189C). All of the variants were de novo in origin. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.3308T>A (p.V1103D) and c.3565C>T (p.R1189C) variants were rated as likely pathogenic (PS2+PM2&#95;Supporting+PP3), whilst the remainders were rated as pathogenic (PVS1+PS2+PM2&#95;Supporting)., Conclusion: There is strong clinical and genetic heterogeneity in CS. Early genetic testing may facilitate accurate diagnosis. The detection of novel variants has expanded the phenotypic spectrum of CS and the mutational spectrum of the CHD7 gene.

Objective: To clarify the genetic diagnosis of two children with ring chromosome 18 and explore their mechanisms and clinical phenotypes., Methods: Two patients treated at the Children's Hospital of Henan Province respectively in June 2022 and March 2023 were selected as the study subjects. Genetic testing and diagnosis were carried out through copy number variation sequencing (CNV-seq), G-banded chromosomal karyotyping, and whole exome sequencing (WES)., Results: Child 1 had mainly manifested developmental delay, white matter hypoplasia, type 1 diabetes mellitus, and micropenis. He was found to have a chromosomal karyotype of 46,XY,r(18)(p11.21q22.1)[40]/46,XY[7], and CNV-seq results showed that he has a 14.86 Mb deletion at 18p11.21p11.32 and a 14.02 Mb deletion at 18q22.1q23. Child 2 had peculiar facial features, delayed white matter myelination, developmental delay, atrial septal defect, severe sensorineural deafness, and congenital laryngeal stridor. He was found to have a chromosomal karyotype of 46,XY,r(18)(p11.2q23). CNV-seq result proved that he had a 14.86 Mb deletion at 18p11-21p11.32 and a 20.74 Mb deletion at 18q21.32q23. WES has failed to detect single nucleotide variants (SNVs) in either child, but revealed a large segmental deletion at chromosome 18 in both of them., Conclusion: Both children were diagnosed with ring chromosome 18 syndrome. The different size of the deletional fragments in the 18q region and mosaicism of ring chromosome 18 in child 1 may underlay the variation in their clinical phenotypes. The type 1 diabetes mellitus and micropenis noted in both children are novel features for ring chromosome 18 syndrome.

Objective: To analyze the clinical and genetic characteristics of a child featuring Dias-Logan syndrome., Methods: A child with speech disorders and delayed psychomotor development from childhood who was admitted to the Rehabilitation Medicine Department of Children's Hospital Affiliated to Zhengzhou University in July 2022 was selected as the research subject. Clinical data of the child was collected. Genomic DNA was extracted from peripheral blood samples of the child and his parents. Potential variant was screened by whole exome sequencing, and candidate variant was verified by Sanger sequencing., Results: The child has presented with global developmental delay, microcephaly, special facial features and behavioral problems. Genetic testing revealed a de novo variant of the BCL11A gene, namely c.561&#95;567delACACGCA (p.Q187fs*7), which was classified as pathogenic (PVS1+PS2+PM2&#95;Supporting)., Conclusion: The heterozygous variant of BCL11A gene probably underlay the Dias-Logan syndrome in this child. Above finding has enriched the phenotypic and mutational spectrum of the BCL11A gene and provides a basis for genetic counseling and clinical decision-making.

Objective: To explore the molecular basis for a Chinese pedigree affected with Achromatopsia (ACHM)., Methods: A pedigree with ACHM which was admitted to the Women and Children's Hospital of Ningbo University on April 14, 2023 was selected as the study subject. Whole exome sequencing (WES) was carried out for the proband. Candidate variants were verified by Sanger sequencing and bioinformatic analysis. Related literature was reviewed, and clinical and genetic features of Chinese patients with ACHM due to variants of CNGA3 gene were summarized., Results: WES revealed that the proband and his younger brother had both harbored compound heterozygous variants of the CNGA3 gene, namely c.1190G>T (p.Gly397Val) and c.2013del (p.Gly672ValfsTer69), which were respectively inherited from their mother and father. The c.1190G>T was a known pathogenic variant, whilst the c.2013del was unreported previously. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.2013del variant was predicted to be likely pathogenic (PM2&#95;Supporting+PVS1&#95;Moderate+PM3+PP4). Literature review has identified 41 CNGA3 gene variants among 43 patients from 38 pedigrees, most of which were missense variants and had located in exon 8. Most patients were males, with nystagmus, photophobia, amblyopia and other symptoms during infancy/childhood as the main clinical manifestations, and there was a lack of genotype-phenotype correlation., Conclusion: The c.1190G>T (p.Gly397Val) and c.2013del (p.Gly672ValfsTer69) variants of the GNGA3 gene probably underlay the ACHM in the proband. Discovery of the c.2013del variant has enriched the mutational spectrum of the GNGA3 gene and provided a basis for genetic counseling and reproduction guidance for this pedigree.

Objective: To explore the clinical and genetic characteristics of two children with mental retardation and microcephaly., Methods: Two children who had visited the Anhui Children's Hospital respectively on March 12 and June 22, 2021 were selected as the study subjects. Peripheral venous blood samples were collected from them and their parents, and subjected to chromosomal karyotyping and whole exome sequencing analyses. Candidate variants were verified by Sanger sequencing and pathogenicity analysis., Results: Chromosomal karyotyping and copy number detection of the two children had found no abnormality. Whole exome sequencing revealed that child 1 has harbored a c.471delT (p.Pro157Profs*9) frameshifting variant of the CASK gene, whilst child 2 has harbored a c.1259&#95;1269delCTGAGAATAAC (p.Pro420fs*27) frameshifting variant of the CASK gene. Sanger sequencing confirmed that both variants were de novo in origin. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP), both variants were rated as pathogenic (PVS1+PS2+PP3)., Conclusion: The de novo variants of the CASK gene probably underlay the pathogenesis of mental retardation and microcephaly in both children.

Objective: To explore the genetic basis for a child with pachygyria., Methods: A proband who had visited Qinzhou Maternal and Child Health Care Hospital for pachygyria and mental retardation in June 2020 was selected as the study subject. Clinical data was collected. The child was subjected to whole exome sequencing (WES), and candidate variant was verified by Sanger sequencing., Results: The proband, a 4-year-and-6-month-old female, was clinically diagnosed with megagyrus deformity. WES revealed that she has harbored compound heterozygous variants of the ADGRG1 gene, namely c.781G>T (p.E261*) in exon 6 and c.1369A>C (p.S457R) in exon 11, which were verified by Sanger sequencing to be derived from her mother and father, respectively. Her younger sister was also heterozygous for the c.1369A>C (p.S457R) variant. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were rated as likely pathogenic (PVS1+PM2&#95; Supporting; PM1+PM2&#95;Supporting+PM3+PP3)., Conclusion: The c.781G>T (p.E261*) and c.1369A>C (p.S457R) compound heterozygous variants of the ADGRG1 gene probably underlay the pachygyria malformation in this child.

Objective: To explore the genetic etiology of a child with Primary hypertrophic osteoarthropathy., Methods: A child who was admitted to Zhongnan Hospital of Wuhan University on July 27, 2021 was selected as the study subject. Genomic DNA was extracted from peripheral blood samples of the child and his parents and subjected to whole exome sequencing. Suspected splicing variant was verified by Sanger sequencing of family members. In vitro function was validated through a minigene assay, whilst the suspected exonic deletion was validated by long-fragment PCR., Results: Whole exome sequencing revealed that the child has harbored compound heterozygous variants of HPGD gene, including a heterozygous deletion (exon 3 del) derived from his father and a splicing variant (c.421+1G>T) derived from his mother. Long-fragment PCR verified that the child and his father had both harbored a 7 565 bp heterozygous deletion (c.218-1304&#95;324+6156del), whilst the minigene assay proved that the splicing variant has resulted in skipping of exon 4., Conclusion: The heterozygous c.218-1304&#95;324+6156del deletion and the c.421+1G>T splicing variant of the HPGD gene probably underlay the pathogenesis in this child. Above finding has enriched the mutational spectrum of the HPGD gene and provided a basis for genetic counseling and prenatal diagnosis for this family.

Objective: To explore the genetic etiology of a Chinese pedigree affected with Branchio-oculo-facial syndrome (BOFS) and summarize the prenatal phenotype of BOFS patients., Methods: A pedigree with BOFS which had presented at the Genetics and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University in December 2021 was selected as the study subject. Clinical data of the pedigree was collected. The fetus was subjected to routine prenatal ultrasound scan. Trio-whole exome sequencing (trio-WES) was carried out for the fetus and its parents, and candidate variant was verified by Sanger sequencing. Relevant literature was searched from the database to summarize the prenatal phenotype of BOFS patients., Results: Ultrasound exam suggested the fetus had cleft lip and palate. Its father had presented with high palatal arch, prematurely grayed hair, occult cleft lip, congenital preauricular fistula, red-green color blindness and unilateral renal agenesis. Its grandfather also had high palatal arch, prematurely gray hair, protruding ears, congenital preauricular fistula and hearing disorders. Trio-WES revealed that the fetus and its father had both harbored a heterozygous c.890-1G>A variant of the TFAP2A gene. The same variant was not found in its mother. Sanger sequencing confirmed that its grandfather had also harbored the same variant. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as likely pathogenic (PVS1+PM2&#95;Supporting). Combined with 36 similar cases retrieved from the literature, the prenatal phenotypes of BOFS patients had included growth restriction (25/37), renal abnormalities (10/37), cleft lip and palate (5/37) and oligohydramnios (5/37)., Conclusion: The c.890-1G>A variant of the TFAP2A gene probably underlay the pathogenesis of BOFS in this pedigree. Discovery of the novel variant has enriched the mutational spectrum of the TFAP2A gene. The common prenatal phenotypes of BOFS have included growth restriction, renal abnormalities, cleft lip and palate and oligohydramnios. Delineation of the intrauterine phenotype of BOFS may facilitate its prenatal diagnosis, clinical diagnosis, treatment and genetic counseling.

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.

Objective: To explore the clinical phenotype and genetic etiology for a Chinese pedigree affected with Autosomal dominant polycystic kidney disease (ADPKD)., Methods: A pedigree with ADPKD diagnosed at the Department of Gynaecology of the First Affiliated Hospital of Zhengzhou University in December 2020 was selected as the study subject. Clinical data of the pedigree was collected, and whole exome sequencing (WES) was carried out for the proband. Candidate variants were verified by Sanger sequencing of the proband and her relatives., Results: Fetal ultrasonography showed increased volume and parenchymal echogenicity in both kidneys. The fetus was found to harbor c.11098C>T (p.R3700C) and c.11039T>C (p.F3680S) compound heterozygous variants of the PKD1 gene, which were respectively inherited from its mother and father. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were predicted to be likely pathogenic (PM1+PM2&#95;supporting+PP3)., Conclusion: The c.11098C>T (p.R3700C) and c.11039T>C (p.F3680S) compound heterozygous variants of the PKD1 gene probably underlay the ADPKD in the fetus. Above finding has provided guidance for the genetic counseling and prenatal diagnosis for this pedigree.

Objective: To investigate the genomic profiles and immune microenvironment of olfactory neuroblastoma (ONB). Methods: Nineteen ONB cases diagnosed in the Beijing Tongren Hospital from May 2018 to October 2022 were divided into low-grade and high-grade groups according to the Hyams grading system, including 7 low-grade and 12 high-grade ONB. Whole exome sequencing and multiplex immunofluorescence analyses were performed on tissue samples of these ONB. Results: A total of 929 nonsynonymous alterations were identified in 18 of the 19 ONB (18/19) cases. The most commonly altered cancer-related genes were CTNNB1 (3/19) and ZNRF3 (3/19). The most mutated oncogenic pathways were the WNT and RAS pathways. The median tumor mutation burden (TMB) was 0.45/Mb, ranging from 0 to 3.25. The median tumor neoantigen load (TNB) was 9.39 neoantigens/Mb, ranging from 0 to 38.30. The median allelic mutation tumor heterogeneity (MATH) score was 16.95, ranging from 3.05 to 117.47. Only one of the 19 cases expressed PD-L1 (composite positive score, CPS>1) in the tumor cells. The median percentage of CD8 + tumor-infiltrating lymphocyte (TIL) in the tumor region was 1.08%. No significant differences were observed between the low-and high-grade groups for mutant genes, mutant pathways, TMB, TNB, MATH, PD-L1 expression levels, or CD8 + TILs percentage( P >0.05). However, the low-grade group showed significantly more CD68 + macrophages in both the tumor and total region than the high-grade group. Notably, CD68 + CD163 - macrophages accounted for an average of 80.52% of CD68 + macrophages. Conclusions: CTNNB1 and ZNRF3 are the most commonly altered cancer-related genes. The low expression of PD-L1 and the low percentage of CD8 + TIL indicate that ONB might not be sensitive to immunotherapy. The percentage of M1-type macrophages in low-grade ONB is significantly higher than that in high-grade ONB, suggesting that M1-type macrophages may be involved in the progression of ONB from low-grade to high-grade.

Objective: To investigate the clinical features, molecular etiology, and treatment of a family with Treacher Collins Syndrome 2 (TCS2). Methods: Information of the proband (female, 8 years old) including medical history and family history was collected. Physical examination and examinations concerning laboratory, audiology, and radiology were performed on the proband. Physical examination was also performed on the family members. Genomic DNA of proband was extracted for whole exome sequencing, and then the genomic DNA of family members was extracted for Sanger sequencing. POLR1D and TCS2 related literatures published before August 31,2023 were searched and sifted in PubMed and CKNI databases. The clinical characteristics of TCS2 were summarized. Results: The proband had poor hearing since childhood, with pure tone audiometry indicating conductive hearing loss. She had a smaller jaw, bilateral preauricular fistulas and cup-shaped ear deformities. Temporal bone CT scan revealed deformities in the left external ear canal, bilateral middle ear and inner ear. A bone-conduction hearing aid device was surgically implanted, resulting in restoration of almost normal hearing levels. The proband's mother also had a slightly smaller jaw. Genetic analysis revealed a novel heterozygous variant NM&#95;015972.4:c.38&#95;47del in the POLR1D gene in the proband, which was inherited from her mother. A review of the literature revealed no clear evidence of genotype-phenotype correlation in TCS2. Conclusions: Molecular diagnosis plays a vital role in the diagnosis of TCS2. Patients with normal facial phenotype may be carriers of pathogenic variants in the POLR1D gene and have the risk of passing it to the offsprings with complete penetrance. Proper bone conductive hearing devices can improve the quality of life of TCS2 patients.

Myopia is the most common visual impairment worldwide, and high myopia is the leading cause of vision loss or even blindness, the high prevalence and blindness of which predispose individuals to a great deal of pain through their whole life. In this study, we recruited a three-generations Guangxi family with high myopia. The clinical data and genome DNA of 17 people relatives of the family were collected. According to the results of whole exomes sequence, sanger sequence were applied to identifify the causative gene. A novel missense mutation c.790A>T（p.N264Y）in NYX gene was co-segregating with high myopia in this family. This mutation was absent in 100 controls and publically online available SNP databases including the 1000Genomes Project, ESP6500 and ExAc. Previous study reported a c.792C>G（p.N264K）mutation of NYX associated with congenital stationary night blindness. It is indicated that different amino acid changes at position 264 of NYX might lead to distinct phenotypes. Our finding expands the mutation spectrum of NYX and provides a useful information for further elucidation on genotype-phenotype relationships. [ABSTRACT FROM AUTHOR]

This study reported a family of MLH1 mutation-induced Muir-Torre syndrome (MTS) and evaluated it's clinical and genetic characteristics. A 51 year-old patient with extraorbital cystic sebaceous and colon adenocarcinoma diagnosed in November 2021 in Zhongshan Hospital of Xiamen University was included. The clinical data of the family were collected and a pedigree chart was drawn, which was in line with the Chinese Lynch syndrome diagnostic criteria and was a typical MTS family. NM&#95;000249.4:c.298C>T(p.R100*) of MLH1 gene in exon 3 was detected by whole exome sequencing and multiplex ligation dependent amplification, which is a pathogenic mutation. After the pathogenic mutation was identified, Sanger sequencing was performed on 4 direct members of the family for MLH1 gene, and 3 family members were found to have detected the mutation and included in MTS risk control. Until December 25 2023, follow-up showed the proband patients were not suffered from recurrence or new occurrence of skin or gastrointestinal tumors. The study reported a typical MTS family and found a possible pathogenic nonsense mutation in the MLH1 gene, which provides new evidence for the pathogenicity of this mutation.

Objective: To explore the gene mutation characteristics and the relationship between gene mutations and long-term prognosis in clinical stage ⅠA lung adenocarcinoma patients. Methods: A retrospective analysis was conducted on 63 clinical stage ⅠA lung adenocarcinoma patients who underwent surgical resection at the Cancer Hospital of the Chinese Academy of Medical Sciences from January 2007 to October 2012, with documented postoperative recurrence or metastasis, as well as those who had a follow-up duration of 10 years or more without recurrence or metastasis. Whole exome sequencing (WES) technology was used to analyze the gene mutation profiles in tumor tissues and univariate and multivariate Cox regression analysis were used to clarify the influencing factors for patient prognosis. Results: After long term follow-up, 13 out of the 63 patients (21%) experienced recurrence or metastasis. WES technology analysis revealed that the most common tumor related gene mutations occurred in epidermal growth factor receptor (EGFR), with a mutation rate of 65.1% (41/63), followed by tumor protein p53 (TP53), fatatypical cadherin 1 (FAT1), low density lipoprotein receptor-related protein 1B (LRP1B), mechanistic target of rapamycin (MTOR), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit gamma (PIK3CG), and SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily A, member 4 (SMARCA4), with mutation rates of 30.2% (19/63), 20.6% (13/63), 15.9% (10/63), 15.9% (10/63), 15.9% (10/63), and 15.9% (10/63), respectively. Multivariate Cox regression analysis showed that PIK3CG mutations ( HR =21.52, 95% CI: 3.19-145.01),smoothened (SMO) mutations ( HR =35.28, 95% CI : 3.12-398.39), catenin beta 1 (CTNNB1) mutations ( HR =332.86, 95% CI : 15.76-7 029.05), colony stimulating factor 1 receptor (CSF1R) mutations ( HR =8 109.60, 95% CI : 114.19-575 955.17), and v-Raf murine sarcoma viral oncogene homolog B (BRAF) mutations ( HR =23.65, 95% CI : 1.86-300.43) were independent risk factors affecting the prognosis of clinical stage ⅠA lung adenocarcinoma patients. Conclusions: PIK3CG, SMO, CTNNB1, CSF1R, BRAF gene mutations are closely related to long-term recurrence or metastasis in clinical stage ⅠA lung adenocarcinoma. Patients with these gene mutations should be given closer clinical attention.

Objective: To explore the genetic etiology of fetuses with congenital heart disease (CHD) through whole exome sequencing (WES)., Methods: Thirty seven fetuses identified with CHD by prenatal ultrasonography but with negative results by chromosomal microarray analysis (CMA) at Jinhua Maternal and Child Health Care Hospital from January 2020 to June 2022 were selected as the study subjects, for whom WES was carried out., Results: WES and Sanger sequencing had detected 6 pathogenic or likely pathogenic variants, and 6 variants with unknown clinical significance. The variants had involved 15 loci within 11 genes, in addition with one copy number variation., Conclusion: WES can increase the detection rate for genetic abnormalities among fetuses with CHD, which can facilitate the prenatal diagnosis, evaluation of prognosis and genetic counseling for the couples.

Objective: To explore the genetic basis and pathogenesis for a child with type I Hereditary hemorrhagic telangiectasia (HHTⅠ) and Splenic sinus shore cell hemangioma (LCA)., Methods: A child with HHT complicated with LCA diagnosed at the First Affiliated Hospital of Dali University in April 2022 was selected as the study subject. Clinical data of the child and her relatives were collected, and pathogenic variants were screened by whole exome sequencing. Candidate variant was verified by Sanger sequencing and bioinformatic analysis., Results: The patient, a 16-year-old female, had recurrent epitaxis since childhood, which sometimes necessitated hemostasis treatment. She also had splenectomy due to splenic rupture and was diagnosed with LCA. Her father and grandmother also had a history of recurrent epitaxis. Her father had deceased due to cerebral vascular rupture. The child was found to harbor a c.360+1G>A variant in the ENG gene. The same variant was not found in her asymptomatic mother and brother., Conclusion: The c.360+1G>A variant of the ENG gene probably underlay the pathogenesis in this child.

Objective: To explore the clinical phenotype and genetic basis of a child with Bainbridge-Ropers syndrome (BRPS)., Methods: A child with BRPS who had visited Nanjing Children's Hospital on June 26, 2019 was selected as the study subject. Clinical data of the child was reviewed. Genomic DNA was extracted from peripheral blood samples of the child and her parents. Whole exome sequencing (WES) was carried out, and candidate variant was verified by Sanger sequencing and bioinformatic analysis., Results: The child was a 6-month-old girl with peculiar facial features, feeding difficulties, malnutrition, global developmental delay, hypotonia, mildly elevated aminotransferase and ulnar deviation. Results of WES showed that she has harbored a c.1533&#95;1534del variant of the ASXL3 gene. Sanger sequencing confirmed that neither of her parents has carried the same variant. No similar case had been retrieved from the HGMD and ClinVar databases. No frequency for this variant among Asian populations was available in the ExAC, 1000 Genomes, and gnomAD databases. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.1533&#95;1534del variant of the ASXL3 gene was determined to be likely pathogenic (PVS1+PS2+PM2&#95;Supporting)., Conclusion: The ASXL3 gene c.1533&#95;1534del variant probably underlay the BRPS in this child. Above finding has provided a reference for the clinical diagnosis and genetic counseling for children with similar disorders.

Objective: To explore the clinical and genetic characteristics of three children with Leguis syndrome., Methods: Three children suspected as Legius syndrome at the Henan Children's Hospital for precocious puberty or short stature from June 6, 2019 to August 25, 2022 were selected as the study subjects. Clinical data of the children were collected. All children were subjected to whole exome sequencing, and candidate variants were verified by Sanger sequencing., Results: All of the children (including 2 females and 1 male, and aged 4 years and 6 months, 8 years, and 14 years and 8 months, respectively) had typical café de lait spots. Child 1 also had precocious puberty, and children 2 and 3 had short statures. Genetic testing revealed that all of them had harbored heterozygous variants of the SPRED1 gene, including c.751C>T (p.Arg251Ter194) in child 1, c.229A>T (p.Lys77Ter368) in child 2, and c.1044&#95;1046delinsC (p.R349fs*11) in child 3. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.751C>T (p.Arg251Ter194) variant was predicted to be likely pathogenic, whilst the other two were known pathogenic variants., Conclusion: All of the three children were diagnosed with Leguis syndrome due to variants of the SPRED1 gene, which had manifested as multiple café de lait spots in conjunct with precocious puberty or short statures.

Objective: To explore the clinical characteristics and genetic basis for a fetus with Joubert syndrome., Methods: A pregnant woman who had visited Suzhou Municipal Hospital on February 26, 2021 was selected as the study subject. The fetus and her parents were subjected to whole exome sequencing (WES), and candidate variants were verified by Sanger sequencing. cDNA analysis of her father and RNA sequencing of her sister were also carried out., Results: The fetus was found to harbor compound heterozygous variants of the TCTN1 gene, namely c.624G>A and c.96dupA (p.Glu33Argfs*49), which were inherited from her father and mother, respectively. Her sister also carried the paternal c.624G>A variant, and mRNA transcripts with the c.624G>A variant of the TCTN1 gene were not detected by cDNA analysis of her father and RNA sequencing of her sister. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.624G>A and c.96dupA variants were both classified as likely pathogenic (PVS1+PM2&#95;Supporting)., Conclusion: The compound heterozygous variants of the TCTN1 gene probably underlay the pathogenesis in this fetus. Above finding has also expanded the mutational spectrum of the TCTN1 gene.

Objective: The clinical and molecular genetic characteristics of 46,XY disorders of sex development caused by NR5A1 gene variants in 15 cases were analyzed to improve the understanding of this disease., Methods: The clinical data of children with NR5A1 gene variants diagnosed at the Children's Hospital Affiliated to Zhengzhou University from March 2016 to December 2021 were retrospectively analyzed. Whole exome sequencing was performed to confirm the candidate sites, and Sanger sequencing was performed for validation. The patients were treated and followed up according to their disease characteristics., Results: At the initial diagnosis, 5 of the 15 cases were raised as females and 10 as males. The gonadal tissue was testis without residual Müllerian or ooticular structure, and all had various degrees of genital abnormalities. The average EMS masculinity score was 4.8 (1 ~ 9), including micropenis (100.0%), hypospadias (86.7%), unfused scrotum (46.7%), and abnormal testicular position (60.0%), in which the hypospadias was Ⅱ°~ Ⅳ°. There was no skin pigmentation in 5 patients with growth retardation. Chromosomal karyotypes were 46,XY, adrenocorticotropin and cortisol levels were normal, electrolyte levels were normal, HCG stimulation test in 5 cases had normal response, 9 cases had low response. Anti-Müllerian hormone and statin B had decreased abnormally with age. A total of 14 NR5A1 variants were detected in the 15 children, most of which occurred in exon 4, of which 9 variant loci were not included in the HGMD database as of December 2022., Conclusion: The clinical phenotype of 46,XY abnormal sexual development caused by NR5A1 gene variants is extensive, with the external genitals showing varying degrees of insufficient masculinization. Adrenal involvement is rare.

Objective: To carry out clinical and genetic analysis for a child featuring Brain-Lung-Thyroid syndrome (BLTS)., Methods: A child who had presented at the Children's Hospital Affiliated to Shandong University on May 27, 2022 was selected as the study subject. Clinical data was collected. Trio-whole exome sequencing (Trio-WES) was carried out for the child and his parents, and candidate variant was verified by Sanger sequencing and bioinformatic analysis. The child was given individualized treatment following the diagnosis., Results: The child, a two-year-and-seven-month-old boy, had presented with global developmental delay, ataxia and hypothyroidism. WES revealed that he has harbored a heterozygous c.674C>T variant of the NKX2-1 gene, based on which he was diagnosed with BLTS. CT scan revealed interstitial and parenchymal inflammation in his lungs, which was reduced by budesonide aerosol inhalation., Conclusion: Discovery of the novel c.674C>T variant has enriched the mutational spectrum of the NKX2-1 gene. Budesonide aerosol may be used to treat lung inflammation associated with BLTS.

Objective: To explore the clinical phenotype and genetic variant in a Chinese pedigree affected with Hunter syndrome and create immortalized cell lines for the affected pedigree members., Methods: A pedigree of six members who had visited Xi'an Children's Hospital in July 2022 was selected as the study subject. Clinical data was collected. Whole exome sequencing was carried out for the pedigree members. Candidate variant was verified by Sanger sequencing. In addition, peripheral B lymphocytes were transfected with Epstein-Barr virus to create immortalized cell lines, which were then subjected to enzyme activity analysis., Results: The patient, a five-year-and-seven-month-old boy, had exhibited stiff limbs and enlarged joints. He had developed hernia, scaphocephaly, and barrel chest from 3 months of age. His uncle also had stiff limbs, poor hearing, blindness, and right oblique inguinal hernia. Above features had resembled those of Hunter syndrome. Genetic testing revealed that both the child and his uncle had harbored an IDS (NM&#95;000202.8): c.823G>A (p.D275N) variant, which was unreported previously. Bioinformatic analysis indicated that the D275 to be a highly conserved site, and the D275N variant may affect the stability of the protein's spatial conformation, thereby decrease the catalytic activity of the enzyme. The successfully constructed immortalized lymphoblastoid cell lines for the child and his parents showed increased volume, irregular shape, burr structure and cluster growth. And the value of IDS activity of the patient's immortalized lymphoblastoid cells was below the limit of detection. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as likely pathogenic (PS3+PM2&#95;Supporting+PM5+PP1+PP3)., Conclusion: Above finding has enriched the phenotypic and mutational spectra of Hunter syndrome, and provided a basis for the genetic counseling for this pedigree. The creation of immortalized cell lines has offered a model for further investigation of the impact of variant on the function of IDS and development of targeted drugs.

Objective: To explore the clinical characteristics and variant of CREBBP gene in a fetus with Rubinstein-Taybi syndrome (RSTS)., Methods: A fetus with RSTS diagnosed at the Third Affiliated Hospital of Zhengzhou University in August 2022 was selected as the study subject. Clinical data, amniotic fluid sample of the fetus and peripheral blood samples of its parents were collected for whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing., Results: Foot malformation, cerebellar vermis agenesis, brain agenesis, polysyndactyly of the big toes and other phenotypes were found by prenatal ultrasound. WES revealed that the fetus has harbored a heterozygous c.4684G>T (p.E1562*) variant in exon 28 of the CREBBP gene (NM&#95;004380.3), which was de novo in origin. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be pathogenic (PVS1+PS2&#95;Moderate+PM2&#95;Supporting). After genetic counseling, the couple had opted to terminate the pregnancy and refused autopsy of the fetus., Conclusion: The c.4684G>T (p.E1562*) variant of the CREBBP gene probably underlay the RSTS in this fetus. The newly discovered variant has enriched the mutational spectrum of the CREBBP gene and illustrated that WES is an efficient tool for the prenatal diagnosis of RSTS.

Objective: To explore the clinical features and genetic etiology of a child with Char syndrome., Methods: A child who was presented at the Department of Child Health, Henan Children's Hospital in February 2022 was selected as the study subject. Clinical data of the child was collected, and peripheral blood samples of the child and her parents were collected for the extraction of genomic DNA. Whole exome sequencing was carried out, and candidate variants were verified by Sanger sequencing and bioinformatic analysis., Results: The child had mainly manifested facial dysmorphism, patent ductus arteriosus, growth retardation, curving of fifth fingers and middle toes. Whole exome sequencing revealed that she has harbored a heterozygous c.944A>C (p.Glu315Ala) variant of the TFAP2B gene, which was verified to be de novo by Sanger sequencing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated to be likely pathogenic (PM1+PM2&#95;Supporting+PM6+PP3)., Conclusion: The heterozygous c.944A>C (p.Glu315Ala) variant of the TFAP2B gene probably underlay the Char syndrome in this child. Above finding has expanded the mutational and phenotypic spectra of the TFAP2B gene, which has facilitated early identification and diagnosis of Char syndrome.