Discovery Sheds Light on Huntington's Disease

June 5 -- THURSDAY, June 4 (HealthDay News) -- Scientists have pinpointed a protein that plays a key role in cell death in Huntingdon's disease, a degenerative disorder that leads to uncontrolled movements and loss of intellectual functioning.

The discovery raises hope that drugs could be developed to slow or halt the disease, according to a study in the June 5 issue of Science.

In Huntington's disease, cells in the corpus striatum, the area of the brain that controls movement, gradually die off.

Previous research has shown that people with Huntington's have a genetic defect that produces a mutant version of the protein "huntingtin," which accumulates in cells throughout the body.

But for reasons scientists didn't understand, the protein only kills cells in the corpus striatum. The protein causes little damage to tissues elsewhere.

In the new study, researchers discovered that a tiny protein called "rhes" -- found only in the corpus striatum -- interacts with the mutant huntingtin proteins, causing cell death.

The findings explain the pattern of brain damage in Huntington's disease and suggest strategies for developing new drug therapies, researchers at Johns Hopkins University said.

"It's always been a mystery why, if the protein made by the HD (Huntington's disease) gene is seen in all cells of the body, only the brain, and only a particular part of the brain, the corpus striatum, deteriorates," said Dr. Solomon H. Snyder, a professor of neuroscience at Johns Hopkins. "By finding the basic culprit, the potential is there to develop drugs that target it and either prevent symptoms or slow them down."

Huntington's is a familial disease, passed from parent to child through a gene mutation. A child of someone with Huntington's has a 50-50 chance of inheriting the gene, according to the National Institute of Neurological Disorders and Stroke.

Because the damage from the faulty gene is limited to the corpus striatum, researchers went searching for proteins that interacted specifically and exclusively with the huntingtin protein in that part of the brain.