ABCD1 and X-linked adrenoleukodystrophy: We previously reported that acyl-CoA and phosphatidylcholine species with 24 and 26 carbons accumulate in fibroblasts from X-ALD patients, whereas SM with 26 carbons but not with 24 carbons accumulate in fibroblasts from X-ALD patients [17], indicating that C24-CoA increases in the absence of ABCD1, leading to the increase C26-CoA through a FA elongation pathway.