a group of connective tissue disorders characterized by hyperelasticity and fragility of the skin, hypermobility of the joints, and fragility of the cutaneous blood vessels and sometimes large arteries due to deficient quality or quantity of collagen; the most common types are inherited as autosomal dominant, caused by mutation in one of the following genes: the collagen V alpha-1 gene (COL5A1) on chromosome 9q or the collagen V alpha-2 gene (COL5A2) on 2q or COL3A1 gene on 2q.
