Clinical and genetic studies of a family from Peru affected by spinocerebellar ataxia type 7

INTRODUCTION: Recently the clinical and genetic investigation of cerebellar diseases has experienced an extraordinary advance due to localization of the disorders in different chromosomal loci. This type of investigation has been done in Peru in the last decade, studying a Peruvian family from the Huarochiri province. PATIENTS AND METHODS: A Peruvian family of 65 individuals in five generations, affected by several neurological disturbances associated with ataxia, were studied by clinical, neurological, ophthalmological, neuroradiological and genetic methods. The genetic study was done in the neurogenetics laboratory of the University of Utah (Salt Lake City, United States). RESULTS: The patients showed equilibrium disturbances, gait difficulties, ophthalmoplegia, corticospinal signs, cognitive deficiencies, visual weakness, maculopathy, retinal degeneration, optic nerve atrophy and atrophy of the cerebellum, brain stem and cerebral hemispheres. The DNA in 30 individuals showed, in the neurologically affected, repeated expansion of CAG triplets in the short arm of chromosome 3p. CONCLUSIONS: The findings in this family suggests that they suffer from spinocerebellar ataxia type 7. This could be the first description of the disease in Latin-America.