Figure 6. Sequence analysis of L and M opsin genes in Family 3. Reference sequences of the L and M genes are shown on top of the electropherograms generated from an affected male (4.2) in Family 3. Nucleotides marked with an arrow indicate known differences between the L and M genes or a patient mutation. A shows sequence 5′ to the start codon (capitals) of exon 1. Note presence of single sequence peaks at positions of known nucleotide variation between L and M opsin sequences (arrows), indicating absence of M exon 1. B shows exon 2 sequence with single peaks representing the presence of L nucleotides but absence of M nucleotides at sites of known variation between L and M opsin genes. C shows exon 3 sequence in which M exon 3 only is present. D shows exon 4 sequence in which only M exon 4 sequence is present. E shows exon 4 sequence with a T>C nucleotide substitution (arrow) resulting in C203R missense mutation.