X-linked Dystonia Parkinsonism (XDP)/DYT3 is a combined dystonia characterized by generalized adult-onset dystonia and concurrent parkinsonism in about 50% of cases. XDP is highly prevalent on Panay Island in the Philippines. Neuropathologically, neurodegeneration occurs in the striatum where medium spiny neurons (MSNs) degenerate. Presently, this is the only dystonia documented to have neurodegeneration. We are using Bacterial Artificial Chromosome Transgenesis to develop mouse models of XDP.