A Family of Bethlem Myopathy Caused by a Heterozygous COL6A1 Mutation

ABSTRACT

Collagen-VI-related myopathies are caused by mutations in the COL6A1, COL6A2, and COL6A3 and are known to have a wide phenotypic spectrum, including Bethlem myopathy, Ullrich congenital muscular dystrophy, intermediate phenotype, and limb-girdle muscular dystrophy. These patients present with joint hyperextensibility and/or contractures as well as skin changes and muscle weakness, and so clinicians need to notice those extramuscular symptoms in order to achieve a correct diagnosis. We describe the clinical, pathological, and radiological features in a family with Bethlem myopathy caused by a COL6A1 mutation.