Cone Deactivation Kinetics and GRK1/GRK7 Expression in Enhanced S Cone Syndrome Caused by Mutations in<i>NR2E3</i>

Abstract

The cone-dominant human retina resulting from NR2E3 mutations affords greater understanding of the physiological roles of GRK1 and GRK7 in human cone photoreceptors. Normal deactivation kinetics in human L/M cones can occur without GRK7 when GRK1 is present in ESCS, but does not occur when GRK7 is present but GRK1 is deficient in Oguchi disease. Lack of both GRK1 and GRK7 in S cones of patients with ESCS results in a more pronounced abnormality in deactivation kinetics and suggests the existence of partial compensation by either GRK when the other is deficient.