RT Journal Article SR Electronic T1 On the heredity of retinitis pigmentosa. JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 405 OP 416 DO 10.1136/bjo.66.7.405 VO 66 IS 7 A1 M. Jay YR 1982 UL http://bjo.bmj.com/content/66/7/405.abstract AB The aims of this study are: (1) to determine the frequencies of the various genetic forms of retinitis pigmentosa; and (2) to perform segregation analysis on autosomal dominant, autosomal recessive, and X-linked families. The families studied consisted of 2 series of patients at Moorfields Eye Hospital: (1) 426 families seen in the Genetic Clinic; and (2) 289 families seen in the Electrodiagnostic Department. Comparison between the 2 series identified biases of ascertainment, and it was estimated that the combined series included 53% of simplex cases and a minimum of 15% of X-linked families. Segregation analysis of the Genetic Clinic series showed good agreement with expectation in autosomal dominant and X-linked families, but indicated that no more than 70% of all simplex cases were autosomal recessive. The rest of the simplex cases were mildly affected and may represent fresh autosomal dominant mutations, autosomal dominant transmission with reduced penetrance, the heterozygous state of X-linked disease in some of the females, and phenocopies.