Ataxia caused by mutations in the alpha-tocopherol transfer protein gene.

A 48 year old woman with ataxia with vitamin E deficiency is described. Gene analysis identified two point mutations in exon 1 of the alpha-tocopherol transfer protein (alpha-TTP) gene, one missense mutation and an upstream initiation codon mutation in the 5'-untranslated region (Kozak sequence). The latter mutation is the first one identified in the translation regulatory region. This mutation decreased the level of alpha-TTP protein expression. The clinical features included uncommon urinary disturbance and deafness and relatively rare retinitis pigmentosa. Supplementary therapy increased her serum vitamin E concentration to the normal range with mild improvement of the deep senses.