Presence of plasma branched-chain fatty acids in multineuronal degeneration, hepatosplenomegaly and adrenocortical insufficiency

We have previously reported a unique disorder in two brothers with multisystem neuronal degeneration, hepatosplenomegaly and adrenocortical deficiency. The clinical features were different from Refsum's disease. Biochemical analysis suggested that a metabolic defect of the ω6 polyenoic fatty acid pathway may be involved. In the present study, were have further identified by gas chromatography-mass spectrometry two branched-chain fatty acids, phytanate and pristanate, in these two patients' plasma. This small, but unequivocally elevated amount of branched-chain fatty acids was primarily localized in the triacylglycerols of plasma low density lipoprotein. Such branched-chain fatty acids were not detected in skin, liver and sural nerve samples. These two cases may represent an alternative metabolic error to that found in Refsum's disease leading to phytanate accumulation.