Figure 6. Electrophysiology measurements of three representative cases of the family studied. This figure represents electro-oculograms (EOGs; A), right eye flash electroretinograms (ERGs; B) and right eye multifocal electroretinograms (mfERGs; C) in patients carrying one mutation heterozygously (II-1: p.Y5X; III-2: p.S144G) or both mutations (III-1). Findings are based on ISCEV standard. Patients II-2 and II-3 displayed electrophysiological findings similar to III-2 and patient III-4 displayed electrophysiological findings similar to III-1. Except for II-1, the amplitudes for the light phase of the EOG (A) were abnormal with a reduction in the Arden ratio (EOG light rise <150%). In patient III-1 (and III-4), flash ERGs show generalized decreased rod and cone photoreceptor amplitudes and decreased photopic oscillatory potentials amplitude (Phot-Ops; B). MfERG records a reduced central function with relative preservation of the amplitude response and timing from the surrounding macula (C).