COL5A1 and Ehlers-Danlos syndrome: Classical EDS (cEDS) in humans is a rare autosomal dominant disorder predominantly associated with a deficiency of type V collagen (COLLV) encoded by the COL5A1 and COL5A2 genes, which is a quantitatively minor fibrillar collagen that presents a nearly ubiquitous distribution in a variety of connective tissues [4].