Human homolog of a mouse sequence from the dystonia musculorum locus is on Chromosome 6p12

Dystonia musculorum is a hereditary neurodegenerative disease in mice that affects sensory neurons. In an effort to clone the gene responsible for this disorder, we have assembled a genomic contig spanning 75 kb of the dystonia musculorum (dt) locus. Within this genomic contig, we have identified a small restriction fragment that shows evolutionary conservation to rat, hamster, rabbit, and human genomic DNA. Using this mouse sequence, we have cloned the conserved human genomic fragment. Sequence analysis of the mouse and human genomic fragments revealed that they share a sequence similarity of 82% over 175 bp. A panel of human/rodent somatic cell hybrids was used to map the human genomic sequence to Chromosome (chr) 6, and high-resolution in situ hybridization (FISH) allowed it to be sublocalized to 6p12. The human homolog of the mouse Bpag1 gene, a gene tightly linked to the mouse dt gene, also maps to Chr 6. Thus this comparative mapping reveals a new region of conserved synteny between the chromosomes of mouse and human. Mapping the human homolog of the mouse dt gene enables us to initiate linkage studies to identify neurodegenerative disorders that may be caused by mutations in this gene.