Therapy of X-linked adrenoleukodystrophy: Prognosis based upon age and MRIabnormality and plans for placebo-controlled trials

Evaluation of the therapy of X-linked adrenoleukodystrophy (X-ALD) is hampe red by its rarity and by the striking and unpredictable variation in phenot ypic expression. We present two approaches that may facilitate therapy eval uation. (1) We have analysed data on 377 X-ALD patients who have been follo wed at the Kennedy Krieger Institute for a mean period of 38 months and hav e subdivided them into 18 subgroups on the basis of age and the degree of a bnormality in brain magnetic resonance imaging (MRI) as assessed by the Loe s score (Am. J. Neuroradiol 1994; 15: 1761). We find that grouping on the b asis of age and MRI score provides information that is of significant progn ostic value. (2) We present plans for the development of a placebo-controll ed multicentre international study that will have sufficient biostatistical power to provide objective evaluation of new therapeutic interventions.