Very long chain fatty acid levels in patients diagnosed with multiple sclerosis.

In clinical practice it is not uncommon for patients with adrenomyeloneuropathy or female carriers of adrenoleucodystrophy to have a presenting history and examination compatible with multiple sclerosis. This suggests that there may be an under-diagnosis of adrenoleucodystrophy and its variants in the multiple sclerosis population. We measured levels of very long chain fatty acids, which are typically elevated in the plasma of patients with adrenoleucodystrophy, in a large cohort of patients diagnosed clinically with multiple sclerosis. We tested serum samples from patients with either a first degree relative with multiple sclerosis or those with a primary progressive phenotype. No elevations in very long chain fatty acids were found in the cohort. This study suggests that the number of cases of adrenomyeloneuropathy or adrenoleucodystrophy amongst patients diagnosed clinically with multiple sclerosis is likely to be extremely low. This has important diagnostic implications.