A 7-year-old girl was admitted to the hospital with rapidly progressive vision loss. Since 1 year of age, she had exhibited developmental delay accompanied by visual impairment and neutropenia. Combined with genetic testing and molecular pathogenicity analysis, she was diagnosed with Cohen syndrome (CS) caused by compound heterozygous variants in VPS13B (c.6940+1G>T and c.2911C>T). The c.6940+1G>T variant resulted in exon 38 skipping, leading to a frameshift and premature termination. Reverse transcription quantitative polymerase chain reaction revealed significantly reduced VPS13B gene expression (P<0.05). Bioinformatic analysis suggested that both variants likely produce truncated proteins. This case highlights that integrating clinical features with molecular pathogenicity assessment (DNA, RNA, and protein analysis) can improve early diagnostic accuracy for CS.
Humans ; Female ; Child ; Vesicular Transport Proteins/genetics* ; Developmental Disabilities/etiology* ; Muscle Hypotonia/etiology* ; Myopia/etiology* ; Heterozygote ; Intellectual Disability/etiology* ; Microcephaly/etiology* ; Obesity/genetics* ; Growth Disorders/etiology* ; Retinal Degeneration/genetics* ; Psychomotor Disorders/genetics* ; Fingers/abnormalities*

OBJECTIVE: To analyze two families with inherited dysfibrinogenemia, and explore the molecular pathogenic mechanisms. METHODS: The coagulation indexes of the probands and their family members were detected. The FGA, FGB, and FGG exons and their flanking sequences were amplified by PCR, and the mutation sites were identified by sequencing. SIFT, PolyPhen2, LRT, ReVe, MutationTaster, phyloP, and phastCons bioinformatics software were used to predict the functional impact of the mutation sites. Protein structure and amino acid conservation analysis of the variant were conducted using PyMOL and Clustal X software. RESULTS: The thrombin time (TT) of the proband in family 1 was prolonged to 37.00 s, and Fg∶C decreased to 0.52 g/L. The TT of the proband in family 2 was 20.30 s, and Fg∶C was 1.00 g/L, which was lower than the normal range. Genetic analysis revealed that the proband in family 1 had a heterozygous mutation c.80T>C in FGA, resulting in the substitution of phenylalanine 27 with serine (Phe27Ser). The proband in family 2 had a heterozygous mutation c.1007T>A in FGG, resulting in the substitution of methionine 336 with lysine (Met336Lys). Bioinformatics software prediction analysis indicated that both mutations were deleterious variants. PyMOL mutation models revealed that the Aα chain mutation (Phe27Ser) in family 1 and γ chain mutation (Met336Lys) in family 2 resulted in alterations in spatial structure and reduced protein stability. Clustal X results showed that both Aα Phe27 and γMet336 were highly conserved across homologous species. CONCLUSION Heterozygous mutations of FGA gene c.80T>C and FGG gene c.1007T>A are both pathogenic variants, causing inherited dysfibrinogenemia.
Female ; Humans ; Male ; Afibrinogenemia/genetics* ; Fibrinogen/genetics* ; Heterozygote ; Mutation ; Pedigree

OBJECTIVE: To investigate the gene carrier rate and genotype distribution characteristics of thalassemia in the population of Kunming, and compare the differences of red blood cell (RBC) parameters between β⁺ heterozygous carriers, β⁰ heterozygous carriers and healthy population, as well as between different sexes of adults aged 18-45 years. METHODS: A retrospective analysis of 3 195 cases of thalassemia gene screened in the First Affiliated Hospital of Kunming Medical University from April 1, 2020 to March 31, 2022 was performed to detect 21 mutations of β-globin genes which was common in Chinese people using fluorescence PCR melting curve method. Patients with single heterozygous carrying β-thalassemia gene were divided into β⁺ heterozygote group and β⁰ heterozygote group, while the control group consisted of 219 healthy individuals. Four indices, including RBC, hemoglobin (Hb), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) were collected from all β heterozygous carriers and 219 healthy people, and compared between β⁺ heterozygote group, β⁰ heterozygote group and control group, as well as between β⁺ heterozygous carriers, β⁰ heterozygous carriers and healthy population of different sexes aged 18-45 years. RESULTS: There were 688 cases confirmed thalassemia gene carriers, accounting for 21.53%. Among them, 322 cases were found to have β-globin gene mutations, including 145 cases of β⁺ heterozygote, 151 cases of β⁰ heterozygote, and 14 cases of β⁺ homozygotes as well as β⁺ and β⁰ dual heterozygotes. Additionally, 12 cases were found to have simultaneous mutation or deletion of β-globin and α-globin. The carrier rate of CD26 G>A mutation in β⁺ thalassemia was the highest, accounting for 57.9%, while in β⁰ thalassemia CD17 A>T was the highest, accounting for 46.4%. The erythrocyte parameters of 296 β heterozygous mutation carriers were compared with the normal reference interval, and it was found that 218 cases with RBC value greater than the highest value of reference interval, while 105, 281, and 269 cases with Hb, MCV, and MCH value less than the lowest value of reference interval, respectively. There were significant differences in the 4 erythrocyte parameters between β⁺ heterozygotes, β⁰ heterozygotes and healthy individuals (all P < 0.001), and further comparison between different sexes also showed significant differences (all P < 0.001). CONCLUSIONS The carrier rates of thalassemia gene and β-thalassemia heterozygote are both at high level in Kunming, and there are significant differences in the erythrocyte parameters between β⁺ heterozygous carriers, β⁰ heterozygous carriers and healthy individuals. When genetic counseling, it is necessary to inform and strengthen screening among adults of marriageable age to prevent birth of children with severe thalassemia.
Humans ; beta-Thalassemia/blood* ; Adult ; Heterozygote ; Male ; Female ; beta-Globins/genetics* ; Retrospective Studies ; Middle Aged ; Mutation ; Adolescent ; Genotype ; Erythrocytes ; Erythrocyte Indices ; Young Adult ; China ; Genetic Testing ; Asian People/genetics*

OBJECTIVE: The aim of this study is to analyze the clinical features and genetic etiology of a patient with multiple morphological abnormalities of the sperm flagella (MMAF) retrospectively. METHODS: A severely oligospermic patient from the Reproductive Center of the First Affiliated Hospital of Ningbo University was selected as the study subject. Clinical data and examination results were collected. High-throughput sequencing and bioinformatics were used to analyze the genetic etiology. And Sanger sequencing was employed to validate findings in the family. Transmission electron microscopy (TEM) was used to observe the sperm ultrastructure, and immunofluorescence analysis was performed to examine the localization of FSIP2 protein in the sperm. RESULTS: The patient presented with severe oligospermia, and sperm morphology displayed MMAF. TEM revealed fibrous sheath and 9+2 microtubule structural disruptions in the sperm. Sequencing identified compound heterozygous variants in the FSIP2 gene (c.17798C > T, c.5927T > G), inherited from the father and mother, respectively. According to the guidelines of the American College of Medical Genetics and Genomics, the variants were classified as pathogenic. The patient's spouse underwent intracytoplasmic single sperm injection, resulting in one embryo, but no clinical pregnancy occurred after embryo transfer. CONCLUSION This study reported the mutation of FSIP2 gene c.17798C > T, c.5927T > G in a patient with MMAF. These findings expand the mutational spectrum of the FSIP2 gene and provide insights for genetic and assisted reproductive counseling for patients with MMAF.
Humans ; Male ; Sperm Tail/pathology* ; Heterozygote ; Oligospermia/genetics* ; Spermatozoa ; Mutation ; Infertility, Male/genetics* ; Adult ; Pedigree ; Retrospective Studies ; Sperm Injections, Intracytoplasmic

Objective:To analyze the hearing phenotypes of p. V37I homozygote and compound heterozygote mutation in GJB2 gene, and to provide basis for genetic counseling. Methods:Fifty-three subjects with p. V37I homozygote and compound heterozygote mutation were recruited at Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital from January 2023 to March 2024. All subjects received universal newborn hearing screening（UNHS）, 23-site chip neonatal deafness genetic screening and audiological tests, including ABR, acoustic immittance, DPOAE, ASSR. The results of newborn hearing screening and hearing diagnosis were compared between homozygous mutation group of 30 cases and compound heterozygous mutation group of 23 cases. Results:In 53 cases, the overall refer rate of UNHS was 64.15%（34/53）, the refer rate of homozygous mutation group was 80.00%（24/30）, which was higher than that of compound heterozygous mutation group（43.48%, 10/23）, the difference between the two groups was statistically significant（P<0.05）. Three subjects with p. V37I compound heterozygous mutation had passed UNHS and diagnosed with unilateral mild hearing loss. The average age of diagnosis of 53 cases was （3.77±1.40） months, 25 cases with hearing loss accounted for 47.17%, including 13 cases with unilateral, 12 cases with bilateral, 28 cases with normal hearing accounted for 52.83%. There was no significant difference between homozygous mutation group（56.67%, 17/30） and compound heterozygous mutation group（34.78%, 8/23） in the proportion of confirmed hearing loss（P>0.05）. Among 37 ears of 25 patients with hearing loss, the proportion of mild, moderate and profound hearing loss were 70.27%（26/37）, 27.03%（10/37） and 2.70%（1/37）, respectively. The hearing loss degree of the homozygous mutation group and the compound heterozygous mutation group were mainly mild, accounting for 70.37%（19/27） and 70.00%（7/10） respectively. There was no significant difference between the two groups in the distribution of hearing loss degree（P>0.05）. Conclusion:The probability of hearing loss was 47.17% in infants of GJB2 gene p. V37I homozygote and compound heterozygote mutation, mainly mild hearing loss. There was no difference in the probability of hearing loss and the distribution of hearing loss degree between the two groups. Patients with p. V37I homozygous and compound heterozygous mutation currently diagnosed as normal hearing need continuous clinical follow-up.
Humans ; Connexin 26 ; Heterozygote ; Homozygote ; Female ; Phenotype ; Male ; Mutation ; Connexins/genetics* ; Infant ; Infant, Newborn ; Hearing Tests ; Neonatal Screening ; Deafness/genetics* ; Genetic Testing

OBJECTIVE: To explore the clinical and genetic features of a child with autosomal dominant mental retardation type 40 (MRD40) due to variant of the CHAMP1 gene. METHODS: Clinical characteristics of the child were analyzed. Genetic testing was carried out by low-depth high-throughput and whole genome copy number variant sequencing (CNV-seq) and whole exome sequencing (WES). A literature review was also carried out for the clinical phenotype and genetic characteristics of patients with MRD40 due to CHAMP1 gene variants. RESULTS: The child, a 11-month-old girl, has presented with intellectual and motor developmental delay. CNV-seq revealed no definite pathogenic variants. WES has detected the presence of a heterozygous c.1908C>G (p.Y636*) variant in the CHAMP1 gene, which was carried by neither parent and predicted to be pathogenic. Literature review has identified 33 additional children from 12 previous reports. All children had presented with developmental delay and mental retardation, and most had dystonia (94.1%), delayed speech and/or walking (85.2%, 82.4%) and ocular abnormalities (79.4%). In total 26 variants of the CHAMP1 gene were detected, with all nonsense variants being of loss-of-function type, located in exon 3, and de novo in origin. CONCLUSION The heterozygous c.1908C>G (p.Y636*) variant of the CHAMP1 gene probably underlay the WRD40 in this child. Genetic testing should be considered for children featuring global developmental delay, mental retardation, hypertonia and facial dysmorphism.
Humans ; Intellectual Disability/genetics* ; Genetic Testing ; Phenotype ; Exome Sequencing ; Heterozygote ; Mutation ; Chromosomal Proteins, Non-Histone/genetics* ; Phosphoproteins/genetics*

OBJECTIVE: To explore the clinical characteristics and genetic etiology of a child with Schaaf-Yang syndrome (SYS). METHODS: Peripheral blood samples of the child and his parents were collected and subjected to whole exome sequencing. Sanger sequencing was used for family constellation verification, and bioinformatic analysis was performed for the candidate variant. RESULTS: The child, a 1-year-and-9-month-old boy, had clinical manifestations of retarded growth, small penis, and unusual facies. Genetic testing revealed that the child has harbored a novel heterozygous variant of c.3078dupG (p.Leu1027Valfs*28) of the MAGEL2 gene. Sanger sequencing showed that neither parent of the child carried the same variant. The c.3078dupG(p.Leu1027Valfs*28) variant of the MAGEL2 gene has not been included in the databases of ESP, 1000 Genomes and ExAC. According to the Standards and Guidelines for the Interpretation of Sequence Variants of the American College of Medical Genetics and Genomics (ACMG), the variant was judged to be pathogenic. CONCLUSION The c.3078dupG (p.Leu1027Valfs*28) variant of the MAGEL2 gene probably underlay the SYS in this child, which has further expanded the spectrum of the MAGEL2 gene variants.
Child ; Humans ; Infant ; Male ; Exome Sequencing ; Genetic Testing ; Heterozygote ; Mutation ; Proteins/genetics* ; Developmental Disabilities/genetics*

OBJECTIVE: To explore the genetic basis for a child with mental retardation. METHODS: Whole exome sequencing was carried out for the child. Candidate variant was screened based on his clinical features and verified by Sanger sequencing. RESULTS: The child was found to harbor a c.995_1002delAGACAAAA(p.Asp332AlafsTer84) frameshift variant in the SYNGAP1 gene. Bioinformatic analysis suggested it to be pathogenic. The same variant was not detected in either parent. CONCLUSION The c.995_1002delAGACAAAA(p.Asp332AlafsTer84) frameshift variant of the SYNGAP1 gene probably underlay the mental retardation in this child. Above finding has expanded the spectrum of SYNGAP1 gene variants and provided a basis for the diagnosis and treatment for this child.
Child ; Humans ; Intellectual Disability/genetics* ; Frameshift Mutation ; High-Throughput Nucleotide Sequencing ; Computational Biology ; Heterozygote ; Mutation ; ras GTPase-Activating Proteins/genetics*

OBJECTIVE: To explore the genetic basis for a child with Aspartylglucosaminuria (AGU). METHODS: Clinical data of the patient was analyzed. The child was subjected to trio-whole exome sequencing (WES) and copy number variation sequencing (CNV-seq), and candidate variant was verified by Sanger sequencing. RESULTS: The child was found to harbor homozygous c.319C>T (p.Arg107*) nonsense variant of the AGA gene, for which both of his parents were heterozygous carriers. No abnormality was found by CNV-seq analysis. The c.319C>T (p.Arg107*) variant was not found in population database, HGMD and other databases. Based on guidelines of the American College of Medical Genetics and Genomics, the variant was predicted to be pathogenic (PVS1+PM2+PP3). CONCLUSION The c.319C>T variant of the AGA gene probably underlay the autosomal recessive AGU in this child. Above finding has enabled genetic counseling and prenatal diagnosis for his parents.
Female ; Pregnancy ; Humans ; Child ; Aspartylglucosaminuria ; DNA Copy Number Variations ; Genetic Counseling ; Genomics ; Heterozygote ; Mutation

OBJECTIVE: To explore the clinical phenotype and genetic basis for a Chinese pedigree affected with Oral-facial-digital syndrome type I (OFD1). METHODS: A pedigree with OFD1 who presented at Hebei General Hospital on March 17, 2021 was selected as the subject. Clinical data of the child was collected. Trio-whole exome sequencing (trio-WES) was carried out for the proband and members of her pedigree, and candidate variant was verified by Sanger sequencing. RESULTS: The proband has featured hypotelorism, broad nasal root, flat nasal tip, lobulated tongue, tongue neoplasia, camptodactyly of left fifth finger, syndactyly of right fourth and fifth fingers, and delayed intellectual and language development. Trio-WES revealed that the proband and her daughter, sister and mother have harbored a heterozygous c.224A>G (p.Asn75Ser) variant of the OFD1 gene. The same variant was not found among healthy members from her pedigree. CONCLUSION The c.224A>G (p.Asn75Ser) variant probably underlay the OFD1 in this pedigree. Above discovery has enriched the spectrum of OFD1 gene variants.
Humans ; Female ; Pedigree ; Orofaciodigital Syndromes/genetics* ; East Asian People ; Phenotype ; Heterozygote ; Mutation ; China