Prevalence of retinitis pigmentosa in Slovenia.

Two hundred and twenty-nine symptomatic patients with retinitis pigmentosa were ascertained in Slovenia between 1986 and 1990. Twenty-three further patients were identified while data from 63 families (82 patients) were being collected. After correction for underascertainment, a prevalence of 1 in 6023 was estimated in the Slovene population (1,999,477 in 1990). The highest prevalence of 1 in 1902 was found in the age group 65 years and older. Of 63 analysed families, 17 (27%) showed autosomal dominant, 13 (21%) autosomal recessive, and one family (1.5%) X-linked inheritance; in 30 families (47.5%) isolated cases were found; and in two families the mode of inheritance was impossible to determine.