Figure 5. Full-field ERGs of patients with mutations of the TRPM1 gene. A-D: Full-field ERGs recorded in a normal subject and three affected individuals. The single bright-flash, mixed rod-cone ERGs showed a “negative-type” configuration with a reduced normal a-wave and a significantly reduced b-wave amplitude (A). The scotopic ERGs showed no response after 20 min of dark-adaptation (B). The photopic ERGs showed an apparent a-wave with normal implicit time and a b-wave with delayed implicit time (C). The amplitudes of the 30 Hz flicker ERGs were within normal range (D). The oscillatory potentials were reduced. Arrowheads: stimulus onset. Each patient’s number is noted at left.