A novel ABCR nonsense mutation responsible for late-onset fundus flavimaculatus.

ABSTRACT

PURPOSE: To report the ophthalmologic features of a novel truncating mutation in the ABCR gene in a patient affected with late-onset fundus flavimaculatus (FFM). METHODS: A complete ophthalmologic examination was performed in a 70-year-old patient, including best-corrected visual acuity measurement, slit lamp and fundus examination, fundus photographs, frequent fluorescein and indocyanine green angiographies, visual field testing, color vision analysis, electroretinogram, and electro-oculogram. The 50 exons of the ABCR gene were analyzed using direct sequencing. RESULTS: Fluorescein and indocyanine green angiographies confirmed the diagnosis of FFM. A heterozygous base change was found, resulting in the substitution of an arginine to a stop at codon 152 of the ABCR gene. CONCLUSIONS: A heterozygous nonsense ABCR gene mutation was found in a patient affected with FFM. No other mutation has been identified in the entire coding sequence and the promoter region, suggesting that a heterozygous severe ABCR mutant may be responsible for a mild and delayed FFM phenotype, different from that of age-related macular degeneration.