Novel Mutations in Two Saudi Patients with Congenital Retinal Dystrophy

To report novel mutations in two Saudi children with clinical features of Leber congenital amaurosis (LCA) and Alström syndrome.

Case 1 was a child with phenotypic features of LCA including oculodigital sign, bilateral enophthalmos, nystagmus, pale disc, and retinal changes. Direct sequencing of the coding sequence of GUCY2D revealed a missense mutation affecting highly conserved position (c. 743C > T; p.S248 L). Case 2 describes a girl with marked nystagmus, photophobia, and retinal changes in both eyes with short and stubby fingers tapering at the distal phalanges. The electroretinograms were nonrecordable in each eye. She had a hearing aid in the left ear, mid-facial hypoplasia, bilateral enophthalmos, and insulin dependent diabetes. Mutation screening of candidates genes revealed a pathogenic mutation in ALMS1 gene (c. 8441C > A, p.S2814). Two novel mutations causing phenotypic LCA and Alström syndrome in Saudi patients from consanguineous families expand the genotypic spectrum of congenital retinal dystrophies.