CSNB1 in Chinese families associated with novel mutations in NYX.

X-linked congenital stationary night blindness (CSNB) and NYX mutation have not been reported in Chinese. Here, two Chinese families with the complete form of CSNB (CSNB1) are presented. Linkage analysis of one family mapped the disease to Xp11-Xq13 where NYX is located. Sequence analysis of NYX identified two novel mutations, c.281G>C and c.302T>C, which would result in missense changes of p.Arg94Pro and p.Ile101Thr in the encoded protein. These two mutations were not found in 96 controls. The c.281G>C mutation cosegregated with nyctalopia and myopia. Our results expand the mutation spectrum of NYX and enrich the clinical information related to NYX mutation. The importance of associated myopia with NYX mutations is discussed.