- Genetic mapping of a locus for multiple epiphyseal dysplasia (EDM2) to a region of chromosome 1 containing a type IX collagen gene. Briggs, M.D., Choi, H., Warman, M.L., Loughlin, J.A., Wordsworth, P., Sykes, B.C., Irven, C.M., Smith, M., Wynne-Davies, R., Lipson, M.H. Am. J. Hum. Genet. (1994)