X-linked Congenital Stationary Night Blindness - Genetics

Genetics

Only three rhodopsin mutations have been found associated with congenital stationary night blindness (CSNB). Two of these mutations are found in the second transmembrane helix of rhodopsin at Gly-90 and Thr-94. Specifically, these mutations are the Gly90Asp and the Thr94Ile, which has been the most recent one reported. The third mutation is Ala292Glu, and it is located in the seventh transmembrane helix, in proximity to the site of retinal attachment at Lys-296. Mutations associated with CSNB affect amino acid residues near the protonated Schiff base (PSB) linkage. They are associated with changes in conformational stability and the protonated status of the PSB nitrogen.