FRMD5 encodes a 570-amino acid‐protein that contains an N‐terminal FERM domain and is a member of the FERM (4.1/ezrin/radixin/moesin) protein family.33FRMD5 is highly expressed in retinal bipolar c-10 ganglion cells34 which have been shown to be the origin of nystagmus in congenital stationary night blindness.35 However, the detailed biological function of FRMD5 is largely unknown. Here, RDX is linked to Nystagmus.