OBJECTIVE: To present a report on prenatal diagnosis using direct SPG4 gene analysis in a family with autosomal dominant hereditary spastic paraplegia (AD-HSP). METHODS: Genetic linkage and haplotype analysis were previously carried out with chromosome 2p markers. DNA was obtained from affected individuals, the affected father, the mother, and fetal DNA from an ongoing pregnancy by chorionic villus sampling (CVS) in the first trimester. The spastin gene (SPG4) was completely sequenced. RESULTS: A novel 832insGdelAA frameshift mutation, predicted to cause loss of functional protein, was identified in the affected father and in the fetal DNA. CONCLUSIONS: This is the first report on direct prenatal diagnosis of chromosome 2p-linked AD-HSP (SPG4). In addition, we report a novel SPG4-combined small insertion/deletion mutation in exon 5, which may be the first SPG4 mutational hot spot.