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

Approximately 140 million people worldwide are homozygous carriers of APOE4 (ε4), a strong genetic risk factor for late onset familial and sporadic Alzheimer's disease (AD), 91% of whom will develop AD at earlier age than heterozygous carriers and noncarriers. Susceptibility to AD could be reduced by targeted editing of APOE4, but a technical basis for controlling the off-target effects of base editors is necessary to develop low-risk personalized gene therapies. Here, we first screened eight cytosine base editor variants at four injection stages (from 1- to 8-cell stage), and found that FNLS-YE1 variant in 8-cell embryos achieved the comparable base conversion rate (up to 100%) with the lowest bystander effects. In particular, 80% of AD-susceptible ε4 allele copies were converted to the AD-neutral ε3 allele in human ε4-carrying embryos. Stringent control measures combined with targeted deep sequencing, whole genome sequencing, and RNA sequencing showed no DNA or RNA off-target events in FNLS-YE1-treated human embryos or their derived stem cells. Furthermore, base editing with FNLS-YE1 showed no effects on embryo development to the blastocyst stage. Finally, we also demonstrated FNLS-YE1 could introduce known protective variants in human embryos to potentially reduce human susceptivity to systemic lupus erythematosus and familial hypercholesterolemia. Our study therefore suggests that base editing with FNLS-YE1 can efficiently and safely introduce known preventive variants in 8-cell human embryos, a potential approach for reducing human susceptibility to AD or other genetic diseases.
Humans ; Apolipoprotein E4/genetics* ; Cytosine ; Mutation ; Blastocyst ; Heterozygote ; Gene Editing ; CRISPR-Cas Systems

OBJECTIVE: To explore the genetic characteristics of a child with Focal segmental glomerulosclerosis and neurodevelopmental syndrome (FSGSNEDS). METHODS: A child with FSGSNEDS who had visited Shengli Oilfield Central Hospital on September 15, 2019 was selected as the study subject. Clinical data of the child was collected, and trio-whole exome sequencing (trio-WES), Sanger sequencing, chromosomal karyotyping analysis, and copy number variation sequencing (CNV-seq) were used to analyze the child and his parents. RESULTS: The child, a 3-year-old boy, had manifested developmental delay, nephrotic syndrome, and epilepsy. Trio-WES and Sanger sequencing showed that he has carried a heterozygous c.1375C＞T (p.Q459*) variant of the TRIM8 gene, for which both his parents were of the wild type. Based on guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be pathogenic. No abnormality was found in the chromosomal karyotyping and CNV-seq results of the child and his parents. CONCLUSION The child was diagnosed with FSGSNEDS, for which the c.1375C＞T variant of the TRIM8 gene may be accountable.
Male ; Humans ; Child ; Child, Preschool ; DNA Copy Number Variations ; Glomerulosclerosis, Focal Segmental/genetics* ; Genomics ; Heterozygote ; Karyotyping ; Carrier Proteins ; Nerve Tissue Proteins

OBJECTIVE: To explore the diagnosis, treatment and genetic analysis of an infant with Schaaf-Yang syndrome (SYS). METHODS: An infant suspected for SYS at the Hunan Provincial Children's Hospital on June 10, 2022 was subjected to trio-whole exome sequencing, and Sanger sequencing was used to verify the candidate variant. Structure of the wild-type and mutant proteins was constructed to analyze the potential hazard. RESULTS: The infant was found to harbor a heterozygous frameshifting variant of c.1908delG (p.R637Gfs*65) of the MAGEL2 gene, which was found in neither of his parents. The variant has not been recorded by the public databases, and no relevant literature was retrieved. As the result of the variant, the MAGEL2 protein only retained part of its proline domain, which may lead to destruction and/or down-regulation of its function. CONCLUSION The c.1908delG (p.R637Gfs*65) variant of the MAGEL2 gene probably underlay the pathogenesis in this child. Combined with his clinical characteristics, the child was diagnosed with SYS. Above finding has also enriched the mutational spectrum of the MAGEL2 gene.
Humans ; Infant ; Down-Regulation ; Heterozygote ; Mutation ; Parents ; Proteins

OBJECTIVE: To explore the clinical features and genetic variant in a child with Cerebral creatine deficiency syndrome (CCDS). METHODS: A child who had presented at the Affiliated Children's Hospital of Fudan University on March 5, 2021 was selected as the study subject. Whole exome sequencing (WES) was carried out for the child, and candidate variant was verified by Sanger sequencing. The level of creatine in the brain was determined by magnetic resonance spectroscopy. RESULTS: The patient, a 1-year-and-10-month male, had presented with developmental delay and epilepsy. Both his mother and grandmother had a history of convulsions. MRS showed reduced cerebral creatine in bilateral basal ganglia and thalamus. The child was found to harbor a hemizygous splicing variant of the SLC6A8 gene, namely c.1767+1_1767+2insA, which may lead to protein truncation. The variant was not found in the public databases. Both his mother and grandmother were heterozygous carriers for the same variant. CONCLUSION The hemizygous c.1767+1_1767+2insA variant of the SLC6A8 gene probably underlay the CCDS in this child. Discovery of the novel variant has also expanded the mutational spectrum of the SLC6A8 gene.
Humans ; Male ; Amino Acid Metabolism, Inborn Errors ; Brain ; Creatine/genetics* ; Heterozygote ; Mothers ; Nerve Tissue Proteins ; Plasma Membrane Neurotransmitter Transport Proteins/genetics* ; Infant

OBJECTIVE: To analyze the clinical phenotypes and genetic variants of a Chinese pedigree affected with Hereditary coagulation factor Ⅻ (FⅫ) deficiency. METHODS: A pedigree presented at the First Affiliated Hospital of Air Force Medical University on December 24,2021 was selected as the study subject. Activated partial thromboplastin time (APTT) and coagulation factor Ⅻ activity (FⅫ:C) were determine by a clotting method, and FⅫ antigen was detected with an ELISA assay. Following the extraction of genomic DNA, all exons and flanking regions of the F12 gene were subjected to Sanger sequencing. Clustalx-2.1-win, PROVEAN and Swiss-PDB Viewer software was used to analyze the conservation of amino acids at the variant sites, impact of of the variants on the amino acid substitutions and the protein structure. RESULTS: The APTT of the proband has prolonged to 70.2 s. Her FⅫ:C and FⅫ:Ag have decreased to 12% and 13%, respectively. DNA sequencing revealed that the proband has harbored c.346G>A (p.Gly97Ser) and c.1583C>A (p.Ser509Tyr) heterozygous compound missense variants in exons 5 and 13 of the F12 gene, respectively. Her father and sister were heterozygous carriers for the c.346G>A (p.Gly97Ser) variant, whilst her mother and brother were heterozygous for the c.1583C>A (p.Ser509Tyr) variant. CONCLUSION The c.346G>A (p.Gly97Ser) and c.1583C>A (p.Ser509Tyr) compound heterozygous variants of the F12 gene probably underlay the pathogenesis of hereditary coagulation FⅫ deficiency in this pedigree.
Humans ; Male ; Female ; Pedigree ; Factor XII/genetics* ; Mutation ; East Asian People ; Heterozygote ; Mothers ; Factor XII Deficiency/genetics*