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Mutations in PCDH19, which encodes protocadherin 19, have been identified in epilepsy, mainly in affected females. We summarized the clinical spectrum of female epilepsy patients with PCDH19 mutations in a Chinese population. We screened for PCDH19 mutations in 75 girls diagnosed as Dravet Syndrome (DS) without a SCN1A mutation and 29 girls with fever-sensitive and cluster seizures. We identified 11 novel and 7 reported mutations in 21 of 104 probands (20.2%), including 6 (6/75, 8%) DS girls and 15 (15/29, 51.7%) girls with fever-sensitive epilepsy. The mutations were inherited in 9 probands, de novo in 11, and undetermined in the remaining patient. Shared clinical features included early onset seizures (5–18 months), seizures sensitive to fever, focal seizures or generalized tonic-clonic seizures in clusters and brief seizures. Mental retardation was present in 17 probands. Three patients had features of autism. Two of the nine probands with inherited mutations had no family history of epilepsy, one inherited the mutation from her transmitting father and the other inherited from her asymptomatic mother. Our results confirmed that the clinical spectrum of PCDH19 mutations includes female DS patients, epilepsy and mental retardation limited to females, epilepsy with normal development and asymptomatic female carriers.

Collagen VI-related myopathy, caused by pathogenic variants in the genes encoding collagen VI, represents a clinical continuum from Ullrich congenital muscular dystrophy (UCMD) to Bethlem myopathy (BM). Clinical data of 60 probands and their family members were collected and muscle biopsies of 26 patients were analyzed. COL6A1, COL6A2 and COL6A3 exons were analyzed by direct sequencing or next generation sequencing (NGS). Sixty patients were characterized by delayed motor milestones, muscle weakness, skin and joint changes with 40 UCMD and 20 BM. Muscle with biopsies revealed dystrophic changes and showed completely deficiency of collagen VI or sarcolemma specific collagen VI deficiency. We identified 62 different pathogenic variants in these 60 patients, with 34 were first reported while 28 were previously known; 72 allelic pathogenic variants in COL6A1 (25/72, 34.7%), COL6A2 (33/72, 45.8%) and COL6A3 (14/72, 19.4%). We also found somatic mosaic variant in the parent of 1 proband by personal genome machine amplicon deep sequencing for mosaicism. Here we provide clinical, histological and genetic evidence of collagen VI-related myopathy in 60 Chinese patients. NGS is a valuable approach for diagnosis and accurate diagnosis provides useful information for genetic counseling of related families.

Laminin-α2 deficient congenital muscular dystrophy (CMD) is an autosomal recessive disorder characterized by severe muscular dystrophy, which is typically associated with abnormal white matter. In this study, we assessed 43 CMD patients with typical white matter abnormality and laminin-α2 deficiency (complete or partial) diagnosed by immunohistochemistry to determine the clinical and molecular genetic characteristics of laminin-α2 deficient CMD. LAMA2 gene mutation analysis was performed by direct sequencing of genomic DNAs. Exonic deletion or duplication was identified by multiplex ligation-dependent probe amplification (MLPA) and verified by high-density oligonucleotide-based CGH microarrays. Gene mutation analysis revealed 86 LAMA2 mutations (100%); 15 known and 37 novel. Among these mutations, 73.9% were nonsense, splice-site or frameshift and 18.8% were deletions of one or more exons. Genetic characterization of affected families will be valuable in prenatal diagnosis of CMD in the Chinese population.