Myopia is the most common visual impairment worldwide, and high myopia is the leading cause of vision loss or even blindness, the high prevalence and blindness of which predispose individuals to a great deal of pain through their whole life.?In this study, we recruited a three-generations Guangxi family with high myopia. The clinical data and genome DNA of 17 people relatives of the family were collected. According to the results of whole exomes sequence, sanger sequence were applied to identifify the causative gene. A novel missense mutation c.790A>T(p.N264Y)in NYX gene was co-segregating with high myopia in this family. This mutation was absent in 100 controls and publically online available SNP databases including the 1000Genomes Project, ESP6500 and ExAc. Previous study reported a c.792C>G(p.N264K)mutation of NYX associated with congenital stationary night blindness. It is indicated that different amino acid changes at position 264 of NYX might lead to distinct phenotypes. Our finding expands the mutation spectrum of NYX and provides a useful information for further elucidation on genotype-phenotype relationships.