Figure 1. Pedigrees of four Chinese families with autosomal dominant retinitis pigmentosa associated with mutations in the PRPF31 gene. Genotypes are shown beneath the symbols. Affected individuals are represented by black symbols, unaffected ones by unfilled, asymptomatic ones by gray; squares signify males, circles females. Arrows mark the index patients. M refers to the mutant allele, and + means normal allele.