Fig. 1 - Family carrying homozygous PDE6B mutations.

a. The exon 4 sequence variant in this family was first detected by SSCPE. Both parents (M and F) are heterozygous for this variant, and both unaffected siblings (S1 and S2) are homozygous normal, as is the unaffected control (C); the proband (P) is homozygous for this variant. The parents are first cousins.

b. Sequence of the exon 4 mutation segregating with disease. The homozygous normal siblings (center) have the sequence TGC at codon 270 for Cysteine, the proband (right) has the sequence TGA for stop, and each of the parents (left) has one allele with TGC and the other with TGA resulting in TG C/A. Sequences are read from the bottom up.