We have investigated the effect of glyceroltrioleate/glyceroltrierucate (GTO/GTE) therapy on X-chromosomal adrenoleukodystrophy in 16 patients with adrenoleukodystrophy (n = 6), adrenomyeloneuropathy (n = 3), Addison disease without neurological involvement (n = 2), and neurologically and endocrinologically asymptomatic patients (n = 5). Therapy was carried out for 19.4 +/- 10 months. All patients showed a normalization of C 26:0 plasma fatty acid concentrations. None of the seven neurologically asymptomatic patients developed neurological symptoms. Somatosensory evoked potentials of the tibialis nerve was the most sensitive electrophysiological parameter, showing a slight improvement in neurologically asymptomatic patients during therapy. In none of the patients with normal cranial MRI at start of therapy (n = 6) has MRI deterioration been observed whilst on therapy. Follow up of the neurologically asymptomatic children supports the hypothesis that GTO/GTE therapy might prevent the development of neurological symptoms. Six of the nine neurologically symptomatic patients deteriorated to varying degrees whilst on therapy. MRI alterations have worsened in all patients with clinical deterioration.
Conclusion: GTO/GTE treatment should be initiated in all neurological asymptomatic boys before first neurological symptoms develop. To discover these patients very long-chain fatty acid determination should be performed in all family members at risk when adrenoleukodystrophy or adrenomyeloneuropathy is diagnosed.