Purpose. To characterize the clinical phenotype and identify the disease-causing mutation in a family with X-linked ocular albinism (OA1). Methods. 32 members of a family affected with OA1 were examined, and linkage analysis was performed with markers from the OA1 locus. Exons 2 and 8 of the OA1 gene were assayed with the polymerase chain reaction (PCR). Results. The 6 affected males had visual acuities ranging from 20/40 to 20/200. All had nystagmus, iris transillumination, and foveal hypoplasia. The eldest affected male was asymptomatic with 20/40 vision. All 7 female carriers had normal visual function but were found to have iris transillumination defects and variable mosaic pigmentary patterns of the retinal pigment epithelium (RPE). Linkage analysis was consistent with a disease-causing mutation at the OA1 locus. PCR analysis revealed a deletion which includes at least the portion of the OA1 gene between exons 2 and 8. Conclusions. Males affected with OA1 can have a visual disability that ranges from almost none to legal blindness. In this family, the visual acuity seemed related more to the degree of nystagmus than to the degree of RPE pigmentation. Mutation screening of the OA1 gene can be used to confirm the diagnosis in isolated males of some families and genetic linkage analysis can be used to accurately identify carriers even when the specific mutation can't be identified.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience