Serum Vitamin E and Lipid-adjusted Vitamin E Assessment in Friedreich Ataxia Phenotype Patients and Unaffected Family Members

Abstract

Friedreich ataxia (FA) is an autosomal recessive spinocerebellar syndrome with onset before age 25, characterized by progressive cerebellar ataxia, dysarthria, areflexia, sensory loss in lower limbs, pyramidal weakness, and Babinski signs (1). It is caused by an intronic expanded unstable GAA repeat in the frataxin gene (2) located on chromosome 9q13-q21 (3). Investigating five Tunisian families with typical FA phenotype, Ben Hamida et al. (4) had excluded linkage to the locus of FA in two families and provided evidence for genetic heterogeneity of the disease. Patients belonging to families not linked to the locus of FA showed very low serum vitamin E (VE) with no evidence of lipid malabsorption. The role of VE in maintaining human nervous system function is established, and the role of VE deficiency in neurologic disorders of a-β-lipoproteinemia and biliary atresia is well accepted (5)(6). Several reports (4)(7)(8)(9)(10) have described patients with a progressive spinocerebellar syndrome associated with very low serum VE in the absence of fat malabsorption or a-β-lipoproteinemia. This disease, termed ataxia with VE deficiency (AVED), is inherited with an autosomal recessive pattern (3)(4). The abnormal gene was mapped to chromosome 8q (11) and identified as the gene encoding for α-tocopherol transfer protein (α-TTP) (12). Because it is difficult to distinguish on the basis of clinical features between AVED patients in whom VE supplementation may be beneficial (7)(13)(14) and those with classic FA, we assessed serum VE, total cholesterol (TC), and triglycerides (TGs) in our patients with FA clinical phenotype …