GUCY2D and Leber congenital amaurosis: The point mutations L945P and P858S in the guanylyl cyclase RetGC-1 expressing gene GUCY2D causing autosomal recessive inherited Leber congenital amaurosis (LCA) were found to reduce the activity of wild type RetGC-1, thus representing an example of a dominant-negative mutation causing a recessively inherited disease68.