Collagen VI deficiency (Q103663)

Condition characterized by deficiency of collagen VI, an extracellular matrix protein that forms a microfibrillar network in the reticular layer of the basement membrane and functions to anchor the basement membrane to the underlying connective tissue. Caused by autosomal dominant or recessive mutations in the three major α-chains of collagen type VI (COL6A1, COL6A2, and COL6A3). Presents with early onset hypotonia, weakness, and contractures of the elbows, ankles, interphalangeal joints of the fingers.