Mapping of a new form of pure autosomal recessive spastic paraplegia (SPG28).

Pure hereditary spastic paraplegias are characterized by isolated and progressive spasticity in the lower limbs. We mapped the spastic paraplegia 28 (SPG28) locus to chromosome 14q21.3-q22.3 in a Moroccan family with autosomal recessive hereditary spastic paraplegia. Affected patients experienced development of progressive spastic gait during childhood and required help walking in their early 40s. Nine additional hereditary spastic paraplegia families were not linked to this locus, demonstrating further genetic heterogeneity. No mutations were found in exons of GCH1 and SPG3A, two genes from the candidate region involved in movement disorders.