EPIDEMIOLOGY OF RETINITIS-PIGMENTOSA IN THE VALENCIAN COMMUNITY (SPAIN)

The purposes of this study are to determine the frequencies of the dif ferent genetic forms of retinitis pigmentosa and to perform segregatio n analysis in the different genetic subtypes. Retinitis pigmentosa was diagnosed in 263 persons from 132 families. The frequency of the auto somal recessive type was the highest (31.8%) while the X-linked type w as very rare (1.5%). The frequency of autosomal dominant type was 14.4 % and the simplex cases constituted half of the total cases of RP regi stered in our community. In conclusion, in our population the high pro portion of simplex cases and the low number of X-linked families are n oticeable. The result of segregation analysis showed good agreement wi th expectation in autosomal dominant and autosomal recessive families but no more than 60% of all simplex cases were autosomal recessive. Th e proportion of sporadic cases was estimated statistically to be 39.9% of the total simplex cases. (C) 1995 Wiley-Liss, Inc.