Unusual retinal phenotypes in an SCA7 family.

We report the cases of a father and his son with spinocerebellar ataxia type 7 (SCA7), a disorder rarely reported in Japan. The father had noticed dysarthria at age 38, and gait instability at age 46. Visual disturbance was noted 3 years later. Neurological examination at age 54 revealed visual disturbance, dysarthria, and cerebellar ataxia in all four extremities and the trunk. Cranial MRI showed moderate atrophy of the brain stem and cerebellar hemispheres. However, no retinal degeneration was found. The son was 16 years old at our first examination. Since age 6, his visual acuity began to decrease; at age 10, he noticed clumsiness in his hands. Six years later he began to experience gait instability. Neurological examination revealed visual disturbance and cerebellar ataxia. He was diagnosed with SCA7 by genetic analysis. His ophthalmologic examination showed retinal degeneration without pigmented spots, which is different from those of retinal phenotypes previously described in SCA7.