- Huntington disease-linked locus D4S111 exposed as the alpha-L-iduronidase gene. MacDonald, M.E., Scott, H.S., Whaley, W.L., Pohl, T., Wasmuth, J.J., Lehrach, H., Morris, C.P., Frischauf, A.M., Hopwood, J.J., Gusella, J.F. Somat. Cell Mol. Genet. (1991)