Frameshift mutation in the collagen VI gene causes Ullrich's disease.

Patients with Ullrich's disease have generalized muscle weakness, multiple contractures of the proximal joints, and hyperextensibility of the distal joints. Recently, we found a deficiency of collagen VI protein in two patients with Ullrich's disease. In this study, we detected a homozygous 26 bp deletion in exon 14 of the collagen VI alpha 2 gene (COL6A2) in one patient. This mutation causes a frameshift and a premature termination codon, and results in a truncated collagen VI alpha 2 chain. Our data suggest that at least some cases of Ullrich's disease result from recessive mutations in COL6A2.