Effects of polyunsaturated fatty acid diets on plasma lipids of patients with adrenomultineuronal degeneration, hepatosplenomegaly and fatty acid derangement.

The effect on plasma fatty acid composition of 3-6 weeks feeding of standard diets supplemented with various omega 6 polyenoic fatty acids (18:2, 18:3, 20:3 or 20:4) was studied in two young brothers with multineuronal degeneration plus. These boys had mental retardation or maldevelopment, neurosensory hearing loss, retinitis pigmentosa, progressive muscular atrophy, hepatosplenomegaly and adrenal failure. The study objectives were to localize the site of metabolic block and to assess the safety and short-term clinical effect of dietary treatment. Our studies have shown that the low plasma levels of 20:4 omega 6 can be corrected by feeding ethyl arachidonate and that no adverse effects were experienced. A diet enriched in ethyl linoleate produced no obvious increases of 18:2 omega 6 metabolites, indicating that these patients do not have a linoleate deficiency in their omega 6 polyenoic fatty acid pathway. Lack of incorporation of 20:4 omega 6 and a retroconversion of 20:3 omega 6 to 18:2 omega 6 after a dihomo-gamma-linolenate-enriched diet suggest that a defect of delta 5 desaturase may be involved.