Collagen Type VI-Related Disorders Panel

The collagen type VI-related disorders are nowadays considered to be a continuum of overlapping phenotypes with Bethlem myopathy at the mild end and Ullrich congenital muscular dystrophy (UCMD) at the severe end. In between these phenotypes there are collagen type VI-related limb-girdle muscular dystrophy and myosclerosis myopathy. Most cases of Bethlem myopathy have autosomal dominant inheritance of COL6A1, COL6A2 or COL6A3 mutations. Ullrich congenital muscular dystrophy (UCMD) was thought to be a recessive condition until it was shown to be inherited in a dominant manner in numerous cases. Recently, both dominant and recessive mutations in another collagen gene (COL12A1) have been found in patients with both Ullrich and Bethlem phenotypes.