Congenital Stationary Night Blindness Type 2 Mutations S229P, G369D, L1068P, and W1440X Alter Channel Gating or Functional Expression of Cav1.4 L-type Ca2+Channels

Abstract
Mutations in the CACNA1F gene (voltage-dependent L-type calcium channel α1F subunit) encoding retinal Cav1.4 L-type Ca2+ channels cause X-linked recessive congenital stationary night blindness type 2 (CSNB2). Many of them are predicted to yield nonfunctional channels. Complete loss of Cav1.4 function is therefore regarded as a pathogenetic mechanism for the impaired signaling from photoreceptors to second-order retinal neurons. We investigated the functional consequences of CSNB2 missense mutations S229P, G369D, and L1068P and the C-terminal truncation mutant W1440X.