A total of 8 members of two consanguineous Tunisian families affected with Friedreich’s ataxia (FA) phenotype not linked to chromosome 9 were found to have very low levels of serum vitamin E (0.5 mcg/ml cf 8 mcg/ml in controls) in a study at the Institut National de Neurologie, Tunis, and at Centers in Cyprus and France. All patients had typical signs of FA: severe ataxia, bilateral Babinski signs, pes cavus, scoliosis, and absent tendon reflexes and proprioception. The mean age at onset was 11 years, and 6 patients were wheelchair-bound at examination at 20 - 30 years of age. Cardiomyopathy was found in 5. Parents and healthy sibs had normal serum vitamin E levels, pointing to an autosomal recessive trait in affected members. Cystic fibrosis, abetalipoproteinemia, and fat malabsorption syndromes were excluded as possible causes of vitamin E deficiency. This FA with selective vitamin E deficiency was mapped to chromosome 8q, confirming its specificity. [1]

COMMENT. The neurological syndrome of vitamin E deficiency is reviewed in an editorial by Dr HJ Kayden, Dept of Medicine, New York University Medical Center, New York [2]. Abetalipoproteinemia and cholestatic liver disease are characterized by fat malabsorption, resulting in steatorrhea and vitamin E deficiency. In familial isolated vitamin E deficiency, lipid and vitamin E absorption and plasma lipoproteins are normal but conservation of plasma a-tocopherol is poor due to impaired secretion in very low-density lipoproteins. Patients must maintain continuous supplementation with vitamin E (600 IU twice daily, 5-10 mg/kg).

The observation that some patients with typical signs of Friedreich’s ataxia have a familial vitamin E deficiency syndrome emphasizes the recommendation that all patients with ataxia and neuropathy should have plasma vitamin E determinations. Early supplementation with vitamin E should halt progression of ataxia, and genetic linkage analysis may establish the diagnosis. Asymptomatic sibs should be tested in early childhood, since vitamin E may prevent the onset of ataxia in those affected.