Abstract
Purpose:
To identify gene mutations in two Chinese families with X-linked congenital stationary night blindness (CSNB)
Methods:
Two families with X-linked congenital stationary night blindness (CSNB) were recruited and patients underwent ophthalmological and electroretinography (ERG) examinations. Blood samples were collected and DNA was extracted. Two candidate genes of NYX and CACNA1F were directly sequenced and mutations analyzed. Two online programs of Polymorphism Phenotype (PolyPhen) and Sorting Intolerant From Tolerant (SIFT) were used to predict the potential impact of an amino acid substitution on the function of the protein. The molecular model were built using Swiss-model.
Results:
Most affected males showed variable degrees of myopia, a nearly normal fundus appearance, nystagmus and strabismus, as well as abnormal ERG with absence of rod b-wave and oscillatory potentials under the scotopic condition. Two NYX gene mutations were detected in the families, including a missense mutation of c.214A>C (p.N72H) and a small deletion of c.371_377del GCTACCT (p.Y125TfsX138), which were absent in 100 normal controls after sequencing of the NYX.
Conclusions:
These two novel mutations would expand the mutation spectrum of NYX gene and contribute to the study of the NYX gene’s molecular pathogenesis.