Figure 3. Electrophysiology of patients 1.2 and 2.1 with normal (N) for comparison. In both eyes of patient 1.2, there was severely subnormal rod-specific electroretinogram (ERG, DA 0.01) delayed and subnormal cone-specific ERGs (LA 30Hz and LA 3.0) and markedly subnormal pattern ERG (PERG). Findings were consistent with a rod-cone pattern of dysfunction of moderate severity with bilateral macular involvement. Both eyes of patient 2.1 demonstrated extinguished rod responses and residual cone-related activity with extinguished PERG consistent with severe generalized retinal dysfunction and severe macular involvement.