Choroideremia (CHM) is an X-linked recessive eye disease that results from mutations involving the Rah escort protein-1 (REP-I) gene. In 18 patients deletions of different sizes have been found, Two females suffering from CHM were reported to have translocations that disrupt the REP I gene. In 22 patients, small mutations have been identified. Interestingly, these are all nonsense, frameshift or splice-site mutations; with one possible exception, missense mutations have not been found. This comprises all the known mutations in the disease. (C) 1997 Wiley-Liss, Inc.