A NEW LOCUS FOR AUTOSOMAL-DOMINANT RETINITIS-PIGMENTOSA ON THE SHORT ARM OF CHROMOSOME-17

Retinitis pigmentosa (RP) is a group of genetically and clinically het erogeneous retinopathies, some of which have been shown to result from mutations in two different known retinal genes, rhodopsin (3q) and pe ripherin-rds (6p). Three additional anonymous loci at 7p, 7q and peric entric 8 have been implicated by linkage studies. There are still, how ever, a few families in which all known loci have been excluded. In th is report we present data indicating a location, on the short arm of c hromosome 17, for the autosomal dominant RP (ADRP) locus in a large So uth African (SA) family of British ancestry. Positive two-point lod sc ores have been obtained for nine markers (D17S938, Z = 5.43; D17S796, Z = 4.82; D17S849, Z = 3.6; D17S786, Z = 3.55; TP53, Z = 3.55; D17S578 , Z = 3.29; D17S960, Z = 3.16; D17S926, Z = 1.51; D17S804, 2 = 0.47 al l at theta = 0.10 except D17S804 and D17S926, theta = 0.20). These dat a provide definitive evidence for the localization of an ADRP gene on chromosome 17p. The human recoverin gene has been localized to 17p13.1 and was consequently a prime candidate for ADRP in the family studied . However, mutation screening of the three exons of this gene failed t o produce any evidence of recoverin being the gene involved in the pat hogenesis of ADRP in this SA family.