OBJECTIVE: To explore the correlation between clinical manifestations of Limb-girdle muscular dystrophy autosomal recessive 9 FKRP-related (R9 FKRP-related) and variants of the FKRP gene. METHODS: Two children who had presented at the Children's Hospital of Nanjing Medical University respectively due to increased serum myocardial zymogram and hepatic dysfunction on September 30, 2018 and August 3, 2018 were selected as the study subjects. Clinical data of the children were collected. Both children were suspected for Duchenne or Becker muscular dystrophy for asymptomatic high creatine kinase (CK) levels. Peripheral blood samples of the children and their parents were collected for whole exome sequencing, and candidate variants were validated by Sanger sequencing. RESULTS: Genetic testing revealed that both children have carried compound heterozygous variants of the FKRP gene. The c.545A>G and c.941C>T variants in child 1 have been reported previously, among which the c.545A>G is a hot spot mutation in the Chinese population. Child 2 has carried c.602T>C and c.961G>A variants, both of which were unreported previously. CONCLUSION Both children have met the diagnostic criteria for LGMD R9 FKRP-related. Carriers of the c.545A>G variant may present milder symptoms. Compared with patients carrying null variants, carriers of compound heterozygous missense variants may present with a milder phenotype, manifesting as asymptomatic high CK level.
Humans ; Child ; Asian People/genetics* ; Genetic Testing ; Muscular Dystrophies, Limb-Girdle/genetics* ; Muscular Dystrophy, Duchenne ; Pentosyltransferases/genetics*

OBJECTIVE: To explore the genetic basis for a neonate featuring developmental delay. METHODS: Clinical examination and laboratory tests were carried out for the patient. Peripheral venous blood samples of the proband and his parents were extracted and subjected to target capture next generation sequencing. Candidate variant was verified by Sanger sequencing. RESULTS: The patient, a four-month-old male, has presented with developmental delay and weakness of limbs. Genetic testing revealed that he had harbored a novel c.1432C>T variant of the TNPO3 gene, which was inherited from his mother. The nonsense variant has resulted in premature termination of protein translation and was predicted to be pathogenic by bioinformatics analysis. CONCLUSION The heterozygous c.1432C>T variant of the TNPO3 gene probably underlay the limb-girdle muscular dystrophies form 1F in this patient. Above finding has enriched the variation spectrum of the TNPO3 gene.
Genetic Testing ; Heterozygote ; High-Throughput Nucleotide Sequencing ; Humans ; Infant ; Male ; Muscular Dystrophies, Limb-Girdle/genetics* ; Mutation ; Phenotype ; beta Karyopherins/genetics*

OBJECTIVE: To analyze the clinical features and genetic variants of three Chinese pedigrees affected with Limb girdle muscular dystrophy type 2I (LGMD2I). METHODS: Clinical data and peripheral blood samples of the three probands and their family members were collected. Whole exome sequencing was carried out for the probands. Candidate variants were verified by Sanger sequencing of their family members. RESULTS: Probands 1 and 2 both featured weakness in the lower limbs. Proband 1 had lost walking ability and had pulmonary ventilation dysfunction. Proband 3 had lower limb pain, palpitations and asthma after exercise. Genetic sequencing revealed that proband 1 harbored compound heterozygous c.545A>G (p.Y182C) and c.1391A>T (p.N464I) variants of the FKRP gene, proband 2 harbored compound heterozygous c.545A>G (p.Y182C) and c.941C>T (p.T314M) variants of the FKRP gene, and proband 3 harbored compound heterozygous c.545A>G (p.Y182C) and c.161G>A (p.R54Q) variants. Among these, the c.161G>A (p.R54Q) variant was unreported previously. CONCLUSION Compound heterozygous variants of the FKRP gene probably underlay the LGMD2I in the three patients. Whole exome sequencing is crucial for the diagnosis of LGMD2I. The identification of the novel variant also broadened the mutational spectrum of the FKRP gene.
Humans ; Pedigree ; Pentosyltransferases/genetics* ; Muscle, Skeletal ; Proteins/genetics* ; Muscular Dystrophies, Limb-Girdle/genetics* ; Mutation ; China

OBJECTIVE: To analyze the clinical phenotype and genetic variants in five Chinese pedigrees affected with Dysferlinopathy. METHODS: Next generation sequencing (NGS) was carried out for the probands from the five pedigrees. Suspected variants were validated by Sanger sequencing. Pathogenicity of the variants was assessed based on the standards and guidelines by the American College of Medical Genetics and Genomics (ACMG). RESULTS: Ten DYSF gene variants (including 5 frameshift variants, 3 splicing variants, 1 missense variant and 1 nonsense variant) were detected. Among these, c.1375dupA (p.Met459Asnfs*15), c.610C>T (p.Arg204X), c.1180+5G>A and c.1284+2T>C were known to be pathogenic, while c.4008_4010delCCTinsAC (p.Leu1337Argfs*8), c.1137_1169del (p.379_390del), c.754A>G(p.Thr252Ala), c.1175_1176insGCAGAGTG (p.Met394Serfs*7), c.3114_3115insCGGC (p.Arg1040Profs*74) and c.1053+3G>C were unreported previously. Of the six novel variants, c.1137_1169del, c.1175_1176insGCAGAGTG and c.3114_3115insCGGC were predicted as pathogenic (PVS1+PM2+PM3), c.4008_4010delCCTinsAC as likely pathogenic (PVS1+PM2), c.754A>G and c.1053+3G>C as variants of uncertain significance based on the ACMG standards and guidelines. CONCLUSION Variants of the DYSF gene probably underlay Dysferlinopathy in the patients among the five pedigrees. Above finding has enriched the spectrum of DYSF gene variants.
Humans ; Muscular Dystrophies, Limb-Girdle/genetics* ; Mutation ; Pedigree ; Phenotype ; RNA Splicing

China ; Dysferlin/genetics* ; Humans ; Muscular Dystrophies, Limb-Girdle/genetics* ; Mutation

Heart ; Humans ; Muscular Dystrophies, Limb-Girdle/genetics*

BACKGROUNDDysferlinopathy is caused by mutations in the dysferlin (DYSF) gene. Here, we described the genetic features of a large cohort of Chinese patients with this disease.

METHODSEighty-nine index patients were included in the study. DYSF gene analysis was performed by Sanger sequencing in 41 patients and targeted next generation sequencing (NGS) in 48 patients. Multiplex ligation-dependent probe amplification (MLPA) was performed to detect exon duplication/deletion in patients with only one pathogenic mutation.

RESULTSAmong the 89 index patients, 79 patients were demonstrated to carry two disease-causing (73 cases) or possibly disease-causing mutations (6 cases), including 26 patients with homozygous mutations. We identified 105 different mutations, including 59 novel ones. Notably, in 13 patients in whom only one pathogenic mutation was initially found by Sanger sequencing or NGS, 3 were further identified to carry exon deletions by MLPA. The mutations identified in this study appeared to cluster in the N-terminal region. Mutation types included missense mutations (30.06%), nonsense mutations (17.18%), frameshift mutations (30.67%), in-frame deletions (2.45%), intronic mutations (17.79%), and exonic rearrangement (1.84%). No genotype-phenotype correlation was identified.

CONCLUSIONSDYSF mutations in Chinese patients clustered in the N-terminal region of the gene. Exonic rearrangements were found in 23% of patients with only one pathogenic mutation identified by Sanger sequencing or NGS. The novel mutations found in this study greatly expanded the mutational spectrum of dysferlinopathy.

Adolescent ; Adult ; Asian Continental Ancestry Group ; Child ; China ; Codon, Nonsense ; genetics ; Dysferlin ; Exons ; genetics ; Female ; Frameshift Mutation ; genetics ; Gene Frequency ; genetics ; Genotype ; High-Throughput Nucleotide Sequencing ; Humans ; Male ; Membrane Proteins ; genetics ; Middle Aged ; Muscle Proteins ; genetics ; Muscular Dystrophies, Limb-Girdle ; genetics ; Mutation ; genetics ; Mutation, Missense ; genetics ; Phenotype ; Young Adult

PURPOSE: This study was designed to investigate the characteristics of Korean patients with calpainopathy. MATERIALS AND METHODS: Thirteen patients from ten unrelated families were diagnosed with calpainopathy via direct or targeted sequencing of the CAPN3 gene. Clinical, mutational, and pathological spectra were then analyzed. RESULTS: Nine different mutations, including four novel mutations (NM_000070: c.1524+1G>T, c.1789_1790inA, c.2184+1G>T, and c.2384C>T) were identified. The median age at symptom onset was 22 (interquartile range: 15-28). Common clinical findings were joint contracture in nine patients, winged scapula in four, and lordosis in one. However, we also found highly variable clinical features including early onset joint contractures, asymptomatic hyperCKemia, and heterogeneous clinical severity in three members of the same family. Four of nine muscle specimens revealed lobulated fibers, but three showed normal skeletal muscle histology. CONCLUSION: We identified four novel CAPN3 mutations and demonstrated clinical and pathological heterogeneity in Korean patients with calpainopathy.
Adolescent ; Adult ; Amino Acid Sequence ; Asian Continental Ancestry Group/*genetics ; Calpain/*genetics ; Female ; Genetic Testing ; Humans ; Male ; Molecular Sequence Data ; Muscle Proteins/*genetics ; Muscle, Skeletal/pathology ; Muscular Dystrophies, Limb-Girdle/ethnology/*genetics/*pathology ; *Mutation ; Republic of Korea

OBJECTIVETo elucidate the usefulness of next generation sequencing for diagnosis of inherited myopathy, and to analyze the relevance between clinical phenotype and genotype in inherited myopathy.

METHODRelated genes were selected for SureSelect target enrichment system kit (Panel Version 1 and Panel Version 2). A total of 134 patients who were diagnosed as inherited myopathy clinically underwent next generation sequencing in Department of Pediatrics, Peking University First Hospital from January 2013 to June 2014. Clinical information and gene detection result of the patients were collected and analyzed.

RESULTSeventy-seven of 134 patients (89 males and 45 females, visiting ages from 6-month-old to 26-year-old, average visiting age was 6 years and 1 month) underwent next generation sequencing by Panel Version 1 in 2013, and 57 patients underwent next generation sequencing by Panel Version 2 in 2014. The gene detection revealed that 74 patients had pathogenic gene mutations, and the positive rate of genetic diagnosis was 55.22%. One patient was diagnosed as metabolic myopathy. Five patients were diagnosed as congenital myopathy; 68 were diagnosed as muscular dystrophy, including 22 with congenital muscular dystrophy 1A (MDC1A), 11 with Ullrich congenital muscular dystrophy (UCMD), 6 with Bethlem myopathy (BM), 12 with Duchenne muscular dystrophy (DMD) caused by point mutations in DMD gene, 5 with LMNA-related congenital muscular dystrophy (L-CMD), 1 with Emery-Dreifuss muscular dystrophy (EDMD), 7 with alpha-dystroglycanopathy (α-DG) patients, and 4 with limb-girdle muscular dystrophy (LGMD) patients.

CONCLUSIONNext generation sequencing plays an important role in diagnosis of inherited myopathy. Clinical and biological information analysis was essential for screening pathogenic gene of inherited myopathy.

Adolescent ; Child ; Child, Preschool ; Contracture ; DNA Mutational Analysis ; Female ; Genetic Diseases, Inborn ; diagnosis ; genetics ; Genetic Testing ; Genotype ; High-Throughput Nucleotide Sequencing ; Humans ; Infant ; Male ; Molecular Diagnostic Techniques ; Muscular Diseases ; diagnosis ; genetics ; Muscular Dystrophies ; congenital ; Muscular Dystrophies, Limb-Girdle ; Muscular Dystrophy, Duchenne ; Muscular Dystrophy, Emery-Dreifuss ; Mutation ; Phenotype ; Sclerosis ; Walker-Warburg Syndrome ; Young Adult

OBJECTIVETo investigate TCAP gene mutation and clinical features of a Chinese patient with limb-girdle muscular dystrophy type 2G(LGMD 2G).

METHODSClinical data of the patient was analyzed. Exons of the TCAP gene were amplified and sequenced.

RESULTSThe patient has presented clinically as LGMD and pathologically as vacuolar myopathy. Genetic analysis has identified compound heterozygous mutations of exons 1 and 2 of the TCAP gene(c.100delC, c.166insG).

CONCLUSIONLGMD is a group of neuromuscular disorders with substantial phenotypic heterogeneity. Genetic diagnosis has become indispensable for accurate diagnosis for patients suspected to have the disease.

Adult ; Base Sequence ; Connectin ; genetics ; Exons ; Female ; Humans ; Molecular Sequence Data ; Muscular Dystrophies, Limb-Girdle ; genetics ; Young Adult