Figure 1. Pedigrees and mutation analysis. A: Shown are six unrelated Caucasus Jewish families in whom the c.1921–9C>G mutation is segregated. Filled symbols represent affected individuals, whereas clear symbols represent unaffected individuals. A double line represents consanguinity. Patients recruited for this study are marked by numbers. +, wild-type (wt) allele; m, mutant allele. B: Nucleotide sequence traces of the boundary between PDE6B intron 15 and exon 16 in a non-carrier individual (wt) and an affected individual homozygote for the c.1921–9C>G mutant allele (hom). The intron–exon boundary is marked. The acceptor splice site (AG) is underlined.