Genetic anticipation in a large family with pure autosomal dominant hereditary spastic paraplegia

Abstract

We have reinvestigated a large kindred identified over 25 years ago segregating for a form of pure autosomal dominant hereditary spastic paraplegia (HSP). We have examined additional relatives in order to refine the clinical and genetic characteristics of this disorder, and performed an analysis to determine if anticipation is present in this family. Analysis of onset ages in parent-to-child transmissions of HSP is consistent with anticipation. These results provide support for dynamic mutation as the underlying mechanism of this form of HSP, and suggest a trinucleotide repeat instability occurring primarily in the female germ line. Am. J. Med. Genet. 83:392–396, 1999. © 1999 Wiley-Liss, Inc.