LESSON OF THE MONTH X-linked adrenoleukodystrophy presenting as autosomal dominant pure hereditary spastic paraparesis

We present a family in which an initial clinical diagnosis of autosomal dominant pure hereditary spastic paraparesis (HSP) was made on the basis of a three generation pedigree in which both males and females presented with a spastic paraparesis. Subsequent biochemical and genetic analysis revealed that the family was in fact affected by the adrenomyeloneuropathy subtype of X-linked adrenoleukodystrophy. In the family described, both males and females were affected by a spastic paraparesis, and there was no male to male transmission, consistent with both autosomal dominant and X-linked inheritance. This report illustrates the importance of assaying very long chain fatty acids (VLCFAs) in any HSP family where there is no male to male transmission.