Background: Dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant spinocerebellar degeneration that exhibits a variety of neurologic manifestations. However, only a few reports have studied disturbances outside the central nervous system. We described 2 unrelated patients with DRPLA accompanied by corneal endothelial degeneration.
Patients and methods: A 52-year-old man presented with cerebellar ataxia and dementia. Magnetic resonance imaging of the brain showed cerebellar atrophy. Dentatorubral-pallidoluysian atrophy was diagnosed because of the detection of expansion of CAG repeats at the DRPLA locus. On admission, his visual acuity was severely impaired. Specular microscopy showed decreased endothelial cell density (500 cells/mm(2)) compared with that of healthy subjects. The second patient was a 69-year-old man with cerebellar ataxia. Magnetic resonance imaging of the brain showed cerebellar and brainstem atrophy. The diagnosis of DRPLA was based on expanded CAG repeats of the DRPLA gene. Specular microscopy showed significant decrease of endothelial cell density (1506 cells/mm(2)). Reverse transcriptase-polymerase chain reaction analysis showed DRPLA gene expression in corneal endothelial cells.
Conclusions: Mutant DRPLA protein may be directly associated with corneal endothelial degeneration. Corneal endothelial cell loss is an important sign of DRPLA, and the corneas of patients with DRPLA should be examined.