Genetic linkage to the collagen alpha 1 (V) gene (COL5A1) in two British Ehlers-Danlos syndrome families with variable type I and II phenotypes.

To investigate the role of COL5A1 as a candidate gene for Ehlers-Danlos syndrome (EDS), we have carried out linkage studies in two large British families with EDS type I/II and type II, respectively. Fourteen living, affected individuals were identified by family history, clinical examination and ultrastructural analysis. A polymorphic intragenic simple sequence repeat at the COL5A1 locus showed linkage to EDS without recombination to give a combined lod score of 5.7. We have previously reported linkage to COL5A1 in an EDS type I/II family which brings the total lod score to 9.8 at zero recombination. Taken together, these data implicate COL5A1 as an important cause of EDS and confirm that types I and II are allelic.