Localization of the gene for rapidly progressive autosomal dominant parkinsonism and dementia with pallido-ponto-nigral degeneration to chromosome 17q21

Rapidly progressive autosomal dominant parkinsonism and dementia with pallido-ponto-nigral degeneration (PPND) is a neurodegenerative disorder which begins later in life (>30 years of age) and is characterized by rapidly progressive parkinsonism, dystonia, dementia, perservative vocalizations and pyramidal tract dysfunction. The disease is observed in a large American family that includes almost 300 members in nine generations with 34 affected individuals. In this kindred evidence for linkage to chromosome 17q21 was obtained with a maximum lod score of 9.08 for the D17S958 locus. Multilocus analysis positions the disease gene in an similar to 10 cM region between 017S250 and 017S943. Notably, the disease locus for a clinically distinct familial neurodegenerative disease named 'disinhibition-dementia-parkinsonism-amyotroph complex' (DDPAC) was recently mapped to the same region of chromosome 17, suggesting that PPND and DDPAC may possibly originate from mutations in the same gene.