Humans ; Consanguinity ; Exome Sequencing ; Mutation/genetics* ; Sequence Analysis, DNA ; Ciliary Motility Disorders ; Axonemal Dyneins/genetics*

Objective:To analyze the phenotype and genotype characteristics of autosomal recessive hearing loss caused by <i>MYO15Ai> gene variants, and to provide genetic diagnosis and genetic counseling for patients and their families. Methods:Identification of <i>MYO15Ai> gene variants by next generation sequencing in two sporadic cases of hearing loss at Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. The sequence variants were verified by Sanger sequencing.The pathogenicity of these variants was determined according to the American College of Medical Genetics and Genomics（ACMG） variant classification guidelines, in conjuction with clinical data. Results:The probands of the two families have bilateral,severe or complete hearing loss.Four variants of <i>MYO15Ai> were identified, including one pathogenic variant that has been reported, two likely pathogenic variants,and one splicing variant of uncertain significance. Patient I carries c. 3524dupA（p. Ser1176Valfs*14）, a reported pathogenic variant, and a splicing variant c. 10082+3G>A of uncertain significance according to the ACMG guidelines. Patient I was treated with bilateral hearing aids with satisfactory effect, demonstrated average hearing thresholds of 37.5 dB in the right ear and 33.75 dB in the left ear. Patient Ⅱ carries c. 7441_7442del（p. Leu2481Glufs*86） and c. 10250_10252del（p. Ser3417del）,a pair of as likely pathogenic variants according to the ACMG guidelines. Patient Ⅱ, who underwent right cochlear implantation eight years ago, achieved scores of 9 on the Categorical Auditory Performance-Ⅱ（CAP-Ⅱ） and 5 on the Speech Intelligibility Rating（SIR）. Conclusion:This study's discovery of the rare c. 7441_7442del variant and the splicing variant c. 10082+3G>A in the <i>MYO15Ai> gene is closely associated with autosomal recessive hearing loss, expanding the <i>MYO15Ai> variant spectrum. Additionally, the pathogenicity assessment of the splicing variant facilitates classification of splicing variations.
Humans ; Pedigree ; China ; Deafness/genetics* ; Hearing Loss/genetics* ; Phenotype ; Hearing Loss, Sensorineural/genetics* ; Mutation ; Myosins/genetics*

Hypertrophic cardiomyopathy (HCM) is the most common monogenic inherited myocardial disease in children, and mutations in sarcomere genes (such as <i>MYH7i> and <i>MYBPC3i>) are the most common genetic etiology of HCM, among which mutations in the <i>MYH7i> gene are the most common and account for 30%-50%. <i>MYH7i> gene mutations have the characteristics of being affected by environmental factors, coexisting with multiple genetic variations, and age-dependent penetrance, which leads to different or overlapping clinical phenotypes in children, including various cardiomyopathies and skeletal myopathies. At present, the pathogenesis, course, and prognosis of HCM caused by <i>MYH7i> gene mutations in children remain unclear. This article summarizes the possible pathogenesis, clinical phenotype, and treatment of HCM caused by <i>MYH7i> gene mutations, in order to facilitate the accurate prognostic evaluation and individualized management and treatment of the children with this disorder.
Child ; Humans ; Cardiomyopathy, Hypertrophic/therapy* ; Phenotype ; Troponin T/genetics* ; Mutation ; Carrier Proteins/genetics* ; Myosin Heavy Chains/genetics* ; Cardiac Myosins/genetics*

OBJECTIVE: To explore the clinical characteristics and genetic basis of a child with Kartagener syndrome (KTS). METHODS: Trio-whole exome sequencing was carried out for the child and his parents, and candidate variants were verified by Sanger sequencing. Changes in protein structure due to missense variants were simulated and analyzed, and the Human Splicing Finder 3.0 (HSF 3.0) online platform was used to predict the effect of the variant of the non-coding region. RESULTS: The child had featured bronchiectasis, sinusitis and visceral inversion. Genetic testing revealed that he has harbored compound heterozygous variants of the DNAH5 gene, namely c.5174T>C and c.7610-3T>G. Sanger sequencing confirmed the existence of the variants. The variants were not found in the dbSNP, 1000 Genomes, ExAC, ClinVar and HGMD databases. Protein structural analysis suggested that the c.5174T>C (p.Leu1725Pro) variant may affect the stability of local structure and its biological activity. The results of HSF 3.0 analysis suggested that the c.7610-3T>G variant has probably destroyed a splicing receptor to affect the transcription process. CONCLUSION The compound heterozygous variants of the DNAH5 gene probably underlay the pathogenesis in the child. Above finding may facilitate the understanding of the clinical characteristics and genetic basis of KTS, and further expand the spectrum of DNAH5 gene variants.
Male ; Humans ; Child ; Mutation ; Kartagener Syndrome/genetics* ; Genetic Testing ; Mutation, Missense ; Exome Sequencing ; Axonemal Dyneins/genetics*

Objective: To investigate the clinical features and gene variation characteristics of children with dynein cytoplasmic 1 heavy chain 1 (DYNC1H1) gene associated spinal muscular atrophy with lower extremity predominant (SMALED) 1. Methods: The clinical data of 4 SMALED1 children admitted to Peking University First Hospital from December 2018 to May 2021, who were found to have pathogenic variation of DYNC1H1 gene through genetic testing, except for other genes known to be related to motor retardation, were retrospectively summarized to analyze the phenotype and genotype characteristics. Results: There were 3 males and 1 female. The age of onset was 1 year, 1 day, 1 day and 4 months, respectively. The age of diagnosis was 4 years and 10 months, 9 months, 5 years and 9 months, and 3 years and 1 month, respectively. The clinical manifestations were muscle weakness and muscular atrophy of lower limbs, 2 cases with foot deformity, 1 case with early non progressive joint contracture, 1 case with hip dislocation and 1 case with mental retardation. De novo heterozygous missense variations in DYNC1H1 gene were found in all 4 children. According to the rating of American College of medical genetics and genomics, they were all possible pathogenic and pathogenic variations, with p.R598C, p.P776L, p.Y1109D variations had been reported, and p.I1086R variation had not been reported. Conclusions: For those with unexplained lower limb muscle weakness, muscle atrophy, joint contracture and foot deformity, upper limb motor ability related retention, with or without mental retardation, as well as the motor ability progresses slowly, it is necessary to consider the possibility of SMALED1 and the detection of DYNC1H1 gene when necessary.
Female ; Male ; Humans ; Intellectual Disability ; Retrospective Studies ; Muscular Atrophy, Spinal/genetics* ; Lower Extremity ; Muscle Weakness ; Muscular Atrophy ; Contracture ; Cytoplasmic Dyneins/genetics*

Primary ciliary dyskinesia (PCD) is a rare hereditary orphan condition that results in variable phenotypes, including infertility. About 50 gene variants are reported in the scientific literature to cause PCD, and among them, dynein axonemal assembly factor 4 ( DNAAF4 ) has been recently reported. DNAAF4 has been implicated in the preassembly of a multiunit dynein protein essential for the normal function of locomotory cilia as well as flagella. In the current study, a single patient belonging to a Chinese family was recruited, having been diagnosed with PCD and asthenoteratozoospermia. The affected individual was a 32-year-old male from a nonconsanguineous family. He also had abnormal spine structure and spinal cord bends at angles diagnosed with scoliosis. Medical reports, laboratory results, and imaging data were investigated. Whole-exome sequencing, Sanger sequencing, immunofluorescence analysis, hematoxylin-eosin staining, and in silico functional analysis, including protein modeling and docking studies, were used. The results identified DNAAF4 disease-related variants and confirmed their pathogenicity. Genetic analysis through whole-exome sequencing identified two pathogenic biallelic variants in the affected individual. The identified variants were a hemizygous splice site c.784-1G>A and heterozygous 20.1 Kb deletion at the DNAAF4 locus, resulting in a truncated and functionless DNAAF4 protein. Immunofluorescence analysis indicated that the inner dynein arm was not present in the sperm flagellum, and sperm morphological analysis revealed small sperm with twisted and curved flagella or lacking flagella. The current study found novel biallelic variants causing PCD and asthenoteratozoospermia, extending the range of DNAAF4 pathogenic variants in PCD and associated with the etiology of asthenoteratozoospermia. These findings will improve our understanding of the etiology of PCD.
Adult ; Humans ; Male ; Asthenozoospermia/genetics* ; Dyneins/genetics* ; East Asian People ; Kartagener Syndrome/genetics* ; Mutation ; Proteins/genetics* ; Semen/metabolism*

OBJECTIVES: To investigate the clinical phenotype and genotype characteristics of children withcardiomyopathy (CM) associated with <i>MYH7i> gene mutation. METHODS: A retrospective analysis was conducted on the medical data of five children with CM caused by <i>MYH7i> gene mutation who were diagnosed and treated in the Department of Cardiology, Hebei Children's Hospital. RESULTS: Among the five children with CM, there were three girls and two boys, all of whom carried <i>MYH7i> gene mutation. Seven mutation sites were identified, among which five were not reported before. Among the five children, there were three children with hypertrophic cardiomyopathy, one child with dilated cardiomyopathy, and one child with noncompaction cardiomyopathy. The age ranged from 6 to 156 months at the initial diagnosis. At the initial diagnosis, two children had the manifestations of heart failure such as cough, shortness of breath, poor feeding, and cyanosis of lips, as well as delayed development; one child had palpitation, blackness, and syncope; one child had fever, runny nose, and abnormal liver function; all five children had a reduction in activity endurance. All five children received pharmacotherapy for improving cardiac function and survived after follow-up for 7-24 months. CONCLUSIONS The age of onset varies in children with CM caused by <i>MYH7i> gene mutation, and most children lack specific clinical manifestations at the initial diagnosis and may have the phenotype of hypertrophic cardiomyopathy, dilated cardiomyopathy or noncompaction cardiomyopathy. The children receiving early genetic diagnosis and pharmacological intervention result in a favorable short-term prognosis.
Male ; Female ; Child ; Humans ; Retrospective Studies ; Cardiomyopathy, Dilated/genetics* ; Pedigree ; Phenotype ; Genotype ; Mutation ; Cardiomyopathy, Hypertrophic/diagnosis* ; Myosin Heavy Chains/genetics* ; Cardiac Myosins/genetics*

Primary ciliary dyskinesia (PCD) is a congenital, motile ciliopathy with pleiotropic symptoms. Although nearly 50 causative genes have been identified, they only account for approximately 70% of definitive PCD cases. Dynein axonemal heavy chain 10 (DNAH10) encodes a subunit of the inner arm dynein heavy chain in motile cilia and sperm flagella. Based on the common axoneme structure of motile cilia and sperm flagella, DNAH10 variants are likely to cause PCD. Using exome sequencing, we identified a novel DNAH10 homozygous variant (c.589C > T, p.R197W) in a patient with PCD from a consanguineous family. The patient manifested sinusitis, bronchiectasis, situs inversus, and asthenoteratozoospermia. Immunostaining analysis showed the absence of DNAH10 and DNALI1 in the respiratory cilia, and transmission electron microscopy revealed strikingly disordered axoneme 9+2 architecture and inner dynein arm defects in the respiratory cilia and sperm flagella. Subsequently, animal models of Dnah10-knockin mice harboring missense variants and Dnah10-knockout mice recapitulated the phenotypes of PCD, including chronic respiratory infection, male infertility, and hydrocephalus. To the best of our knowledge, this study is the first to report DNAH10 deficiency related to PCD in human and mouse models, which suggests that DNAH10 recessive mutation is causative of PCD.
Humans ; Male ; Animals ; Mice ; Semen/metabolism* ; Dyneins/metabolism* ; Cilia/metabolism* ; Mutation ; Ciliary Motility Disorders/genetics*

Objective: To explore the relationship between pathogenic gene, mutation and phenotype of left ventricular noncompaction (LVNC) patients and their family members. Methods: The subjects were the proband with LVNC and her family members. The medical history including electrocardiogram, echocardiography and cardiac magnetic resonance examination of the proband and family members were collected. Whole exome sequencing of the proband was performed, bioinformatics analysis focused on the genes related to hereditary cardiomyopathy. Candidate pathogenic sites were validated by Sanger sequencing. The clinical interpretation of sequence variants were classified according to American College of Medical Genetics and Genomics (ACMG) guidelines. Results: The proband carried a heterozygous variation of the MYBPC3 gene c.C2827T and the MYH7 gene c.G2221C. The proband's sister carried heterozygous variation of MYBPC3 gene c.C2827T. According to the ACMG guidelines, the variant was determined to be pathogenic. Conclusion: The missense variant of MYBPC3 gene c.C2827T and MYH7 gene c.G2221C are identified from the proband with LVNC and her family member, which provides a genetic basis for clinical diagnosis and genetic counseling of the patients and the family members with LVNC.
Female ; Humans ; Cardiac Myosins/genetics* ; Heart Defects, Congenital ; Mutation ; Mutation, Missense ; Myosin Heavy Chains/genetics* ; Pedigree ; Phenotype

Objective: To explore the relationship between pathogenic gene, mutation and phenotype of left ventricular noncompaction (LVNC) patients and their family members. Methods: The subjects were the proband with LVNC and her family members. The medical history including electrocardiogram, echocardiography and cardiac magnetic resonance examination of the proband and family members were collected. Whole exome sequencing of the proband was performed, bioinformatics analysis focused on the genes related to hereditary cardiomyopathy. Candidate pathogenic sites were validated by Sanger sequencing. The clinical interpretation of sequence variants were classified according to American College of Medical Genetics and Genomics (ACMG) guidelines. Results: The proband carried a heterozygous variation of the MYBPC3 gene c.C2827T and the MYH7 gene c.G2221C. The proband's sister carried heterozygous variation of MYBPC3 gene c.C2827T. According to the ACMG guidelines, the variant was determined to be pathogenic. Conclusion: The missense variant of MYBPC3 gene c.C2827T and MYH7 gene c.G2221C are identified from the proband with LVNC and her family member, which provides a genetic basis for clinical diagnosis and genetic counseling of the patients and the family members with LVNC.
Female ; Humans ; Cardiac Myosins/genetics* ; Heart Defects, Congenital ; Mutation ; Mutation, Missense ; Myosin Heavy Chains/genetics* ; Pedigree ; Phenotype