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Variable expression of vision in sibs with albinism
C G Summers1, D Creel, D Townsend
1Department of Ophthalmology, University of Minnesota, Minneapolis 55455.
American Journal of Medical Genetics
|September 1, 1991
Summary
Oculocutaneous albinism (OCA) presents with varied visual acuity, even in affected siblings. Early detection requires careful examination of foveal development in all family members, including those with normal vision.
Area of Science:
- Ophthalmology
- Genetics
- Dermatology
Background:
- Oculocutaneous albinism (OCA) is characterized by hypopigmentation of the skin and eyes, often leading to visual impairment.
- Key ocular features include nystagmus, iris transillumination, reduced retinal pigment, foveal hypoplasia, and optic nerve misrouting.
Observation:
- This report details two brothers with tyrosinase-related OCA exhibiting significantly different visual acuities.
- One brother had 20/100 vision, while the other presented with 20/20 vision, previously undiagnosed despite similar cutaneous pigmentation.
Findings:
- Both brothers demonstrated foveal hypoplasia and optic nerve misrouting at the chiasm.
- Biochemical analysis confirmed a tyrosinase-related form of OCA.
Implications:
- Subtle ocular findings like foveal hypoplasia can indicate albinism even with normal visual acuity.
- Comprehensive family screening, including visual-evoked potentials, is crucial for diagnosing all affected individuals.
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