Increased Synthesis of Hexacosanoic Acid (C26 :0) by Cultured Skin Fibroblasts from Patients with Adrenoleukodystrophy (ALD) and Adrenomyeloneuropathy (AMN)1

Abstract
We studied the metabolism of radioactive stearic acid by cultured skin fibroblasts from patients with adrenoleukodystrophy (ALD) and its variant, adrenomyeloneuropathy (AMN), to clarify the mechanism of the increased content of very long chain saturated fatty acids in cholesterol esters and sphirigolipids, which are known to be the characteristic biochemical changes in ALD and AMN. A substantial amount of hexacosanoic acid (C26 : 0) was synthesized from stearic acid by ALD and AMN fibroblasts, whereas only a trace amount of hexacosanoic acid was synthesized by control fibroblasts. This indicates that the primary biochemical defect in ALD and AMN may involve the elongation system of very long chain fatty acids.