Figure 2. Clinical and molecular data for patient ILCA-100–1 and family. The proband first presented for ophthalmic examination at 4 months of age. When the proband was 3 years old (A), there were no recordable responses to light in the electroretinogram. Examples shown are from the left eye for a dark-adapted combined response and a light-adapted photopic response. Arrowhead marks the timing of the 10-ms bright light pulse. B: The family tree shows the proband (filled circle with arrow) as clinically affected, and both parents are unaffected. C: Bidirectional sequencing showed that the RPE65 Tyr143Asp TAC>GAC mutation was homozygous in the affected proband (P) and was heterozygous in the mother (M) and father (F). Reverse strand sequence around RPE65 Tyr143 (atNacta) is shown against an ethnic unrelated and unaffected control normal (NL).