CONGENITAL MUSCULAR DYSTROPHIES: P.201 Clinical and molecular spectrum associated with COL6A3 c.7447A>G variant: elucidating its role in Collagen VI-related myopathies

Abstract

Dominant and recessive autosomal mutations in the three major genes encoding the extracellular matrix protein collagen VI (COL6A1-A2-A3) underlie a group of myopathies ranging from early-onset severe conditions (Ullrich muscular dystrophy) to milder forms with independent ambulation (Bethlem myopathy). Diagnosis is based on the combination of clinical findings, muscular MRI, muscle biopsy, analysis of collagen VI secretion and genetics, the interpretation of which can be challenging. We report the clinical and molecular findings in 14 patients from 12 families carrying the COL6A3 missense variant c.7447A>G combined with a nonsense, deletion or frameshift COL6A3 mutation and one c.7447A>G homozygous patient.