X-linked adrenoleukodystrophy: Overview and prognosis as a function of ageand brain magnetic resonance imaging abnormality. A study involving 372 patients

The phenotypic expression of X-linked adrenoleukodystrophy (X-ALD) ranges f rom the rapidly progressive childhood cerebral form to the milder adrenomye loneuropathy (AMN) in adults. It is not possible to predict phenotype by mu tation analysis or biochemical assays. This study reports on 372 patients r anging in age from less than 3 years to adulthood, who have been followed a t the Kennedy Krieger Institute. With the aim of determining whether a meth od could be developed to predict clinical course by analysis of data availa ble at time of first contact, the patients were subdivided into 18 subgroup s on the basis of age and the extent of brain magnetic resonance (MRI) abno rmality utilizing the MRI scoring system devised by Lees et al. Scores to g rade degree of neurologic and neuropsychologic impairment were also develop ed. There was strong correlation between MRI and the neurology and neuropsy chology scores at baseline. Information based exclusively on age and MRI sc ore at time of first contact was highly predictive of future clinical cours e and should aid the evaluation of the effects of bone marrow transplantati on and the selection of patients for this procedure, as well as the evaluat ion of other therapies that may be developed in the future.