Tracking Huntington’s Disease

About 3,000 Canadians have Huntington’s Disease, and another 15,000 may be at risk of developing it. Usually afflicting people between the ages of 30 and 50, the disease slowly kills brain cells and results in deterioration of control of movement and of different psychological functions. Every child with a parent with the condition has a 50-50 chance of developing Huntington’s, which currently has no cure or effective treatment.

Researchers with the Canadian Genetics Diseases Network (CGDN) have confirmed that a specific genetic error is associated with almost all cases of Huntington’s Disease. In an article appearing in the prestigious New England Journal of Medicine, CGDN Scientific Director Dr. Michael Hayden and his colleagues report that a specific pattern of DNA changes appears in patients from 43 different countries and across five racial groups, and clearly delineates those affected from normal persons.

"This confirmation will help us to predict who will get the disorder, and to understand the basis for its worldwide distribution," says Dr. Hayden, who leads a team of researchers at the University of British Columbia. The group recently succeeded in cloning the gene for the mouse version of Huntington’s Disease, a development that will be important for understanding the normal function of this gene and the establishment of a model for the illness. "One of our major goals is to determine the function of this gene and to determine how changes in this gene cause illness," says Dr. Hayden.

The cloning achievement, which was published early in 1994 in the journal Human Molecular Genetics, caps a year of progress for the Vancouver researchers, who are trying to understand this inherited disorder. The Vancouver scientists benefitted from new gene tracking and screening techniques developed at Toronto’s Hospital for Sick Children by a team led by Dr. Johanna Rommens.

Dr. Hayden credits much of this success to the support of the Medical Research Council and the Networks of Centres of Excellence, which has enhanced efforts to understand Huntington’s Disease and search for effective methods of treatment."Our collaboration with the Core Technology Facilities of the Canadian Genetic Diseases Network is essential to hasten our research goals of understanding the biochemical cause of this disease," he says.

For more information please visit the CGDN Web site.