Cone-rod dystrophy 2

Cone-rod dystrophy (CORD) characteristically leads to early impairment of vision. An initial loss of color vision and of visual acuity is followed by nyctalopia (night blindness) and loss of peripheral visual fields. In extreme cases, these progressive symptoms are accompanied by widespread, advancing retinal pigmentation and chorioretinal atrophy of the central and peripheral retina (Moore, 1992). In many families, perhaps a majority, central and peripheral chorioretinal atrophy is not found (Tzekov, 1998). Genetic Heterogeneity of Autosomal Cone-Rod Dystrophy There are several other autosomal forms of CORD for which the molecular basis is known. CORD3 (604116) is caused by mutation in the ABCA4 gene (601691) on chromosome 1p22. CORD5 (600977) is caused by mutation in the PITPNM3 gene (608921) on chromosome 17p13. CORD6 (601777) is caused by mutation in the GUCY2D gene (600179) on chromosome 17p13.1. CORD9 (612775) is caused by mutation in the ADAM9 gene (602713) on chromosome 8p11. CORD10 (610283) is caused by mutation in the SEMA4A gene (607292) on chromosome 1q22. CORD11 (610381) is caused by mutation in the RAXL1 gene (610362) on chromosome 19p13. CORD12 (612657) is caused by mutation in the PROM1 gene (604365) on chromosome 4p15. CORD13 (608194) is caused by mutation in the RPGRIP1 gene (605446) on chromosome 14q11. CORD14 (see 602093) is caused by mutation in the GUCA1A gene (600364) on chromosome 6p21. CORD15 (613660) is caused by mutation in the CDHR1 gene (609502) on chromosome 10q23. CORD16 (614500) is caused by mutation in the C8ORF37 gene (614477) on chromosome 8q22. CORD18 (615374) is caused by mutation in the RAB28 gene (612994) on chromosome 4p15. CORD19 (615860) is caused by mutation in the TTLL5 gene (612268) on chromosome 14q24. CORD20 (615973) is caused by mutation in the POC1B gene (614784) on chromosome 12q21. CORD21 (616502) is caused by mutation in the DRAM2 gene (613360) on chromosome 1p13. CORD22 (619531) is caused by mutation in the TLCD3B gene (615175) on chromosome 16p11. CORD23 (see 613428) is caused by mutation in the C2ORF71 gene (PCARE; 613425) on chromosome 2p23. CORD24 (620342) is caused by mutation in the UNC119 gene (604011) on chromosome 17q11. A diagnosis of CORD was made in an individual with a mutation in the AIPL1 gene (604392.0004) on chromosome 17p13.1, as well as in an individual with a mutation in the UNC119 gene (604011.0001) on chromosome 17q11.2. Other mapped loci for autosomal CORD include CORD1 (600624) on chromosome 18q21.1-q21.3; CORD7 (603649) on chromosome 6q14; CORD8 (605549) on chromosome 1q12-q24; and CORD17 (615163) on chromosome 10q26. For a discussion of X-linked forms of cone-rod dystrophy, see CORDX1 (304020). [from OMIM]