Last updated: April 26, 2013
1983: First Disease Gene Mapped
A genetic marker linked to Huntington disease was found on chromosome 4 in 1983, making Huntington disease, or HD, the first genetic disease mapped using DNA polymorphisms.
HD is inherited as an autosomal dominant disease. (In other words, only one of the two copies of the gene need to be mutated to cause disease.) HD causes the death of specific neurons, leading - usually in midlife - to characteristic jerky movements, physical rigidity, and dementia, symptoms that worsen progressively. The gene was finally isolated in 1993. A collaborative group of 58 researchers in 6 research groups isolated a gene called huntingtin located on chromosome 4p16.3.
Gusella, J.F., Wexler, N.S., Conneally, P.M., Naylor, S.L., Anderson, M.A., Tanzi, R.E., Watkins, P.C., Ottina, K., Wallace, M.R., Sakaguchi, A.Y., et al. A polymorphic DNA marker genetically linked to Huntington's disease. Nature, 306(5940):234-8 1983. [PubMed]
Family studies show that the Huntington's disease gene is linked to a polymorphic DNA marker that maps to human chromosome 4. The chromosomal localization of the Huntington's disease gene is the first step in using recombinant DNA technology to identify the primary genetic defect in this disorder.