MSN and pathologic nystagmus: 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.