Total absence of the α2(I) chain of collagen type I causes a rare form of Ehlers-Danlos syndrome with hypermobility and propensity to cardiac valvular problems

Background: Heterozygous mutations in the COL1A1 or COL1A2 gene encoding the α1 and α2 chain of type I collagen generally cause either osteogenesis imperfecta or the arthrochalasis form of Ehlers-Danlos syndrome (EDS). Homozygous or compound heterozygous COL1A2 mutations resulting in complete defici... View More