X-linked spastic paraplegia: evidence for homogeneity with a variable phenotype.

Hereditary spastic paraplegia (HSP) is rarely inherited in an X-linked recessive mode in pure and complicated forms. Recently, molecular linkage studies have suggested that these variant X-linked HSP conditions result from locus heterogeneity. In this paper we report on the clinical and linkage analysis of a kindred with complicated X-linked HSP. The finding in this family of a map location of the putative HSP gene in the same region as the documented for the pure HSP gene provides evidence that allelic mutations might also be responsible for the variable phenotype encountered in these X-linked disorders.