Cone-Rod Dystrophy 1
For a general phenotypic description and a discussion of genetic heterogeneity of cone-rod dystrophy (CORD), see 120970.
MappingWarburg et al. (1991) described a 20-year-old man with mental retardation and electrophysiologically demonstrated cone-rod dystrophy since childhood. He had hypogonadism and a central postsynaptic hearing impairment. Particularly noteworthy was the finding of deletion of the 18q21.1-qter segment. Three patients with more distal deletions on chromosome 18 did not present retinal dystrophies. This led Warburg et al. (1991) to suggest that a locus for cone-rod dystrophy may be located in the segment 18q21.1-q21.3.