North Carolina macular dystrophy (NCMD, MCDR1) is a congenital autosomal dominant trait that appears to be completely penetrant. It is generally nonprogressive. The ophthalmoscopic findings are highly variable and are always much more dramatic than one would predict from the relatively good visual acuity level, which ranges from 20/20 to 20/400 (median, 20/60). Patients may have only a few drusen in the central macular region (grade I), confluent drusen confined to the central macular region (grade II), or a severe macular coloboma/staphyloma (grade III) involving 3 to 4 disc areas of the central macular region. Choroidal neovascular membranes develop in some patients. Color vision is normal. Electrophysiologic studies are also normal (summary by Small, 1998).
Genetic Heterogeneity of Retinal Macular Dystrophy
MCDR2 (608051) is caused by mutation in the PROM1 gene (604365) on chromosome 4p15. MCDR3 (608850) is caused by a duplication on chromosome 5p15. MCDR4 (619977) is caused by mutation in the CLEC3B gene (187520) on chromosome 3p21. MCDR5 (see 613660) is caused by mutation in the CDHR1 gene (609502) on chromosome 10q23.
See MAPPING for possible additional loci for MCDR. [from
OMIM]