Developments in Brief : New Huntington’s Disease Test Found

Researchers at UCLA have developed a test to identify those most likely to develop Huntington’s disease long before they experience its crippling symptoms.

The test, which involves measuring diminished activity in parts of the brain involved in the inherited disease, may even be able to project how long it will be before the debilitating effects begin, they said.

But the UCLA School of Medicine scientists who developed the test said more research is needed to determine the test’s accuracy before it is made available to potential victims who want to use the results to plan their lives. One drawback is that in some cases the test has been found to produce false results.

“Every child who has a parent who has had Huntington’s disease spends a great amount of time wondering,” said Mary Fitzpatrick of the Huntington’s Disease Society of America. “It can be extremely depressing and debilitating.”

Huntington’s disease causes memory and speech loss and uncontrolled body movements, usually beginning between ages 35 and 50. Victims usually die after 15 or 20 years. The cause is unknown and there is no effective treatment.

There are about 25,000 people in the United States with Huntington’s disease and about 125,000 who are at some degree of risk for the disease. Children of victims have about a 50% chance of having inherited the disease.

One recently developed test can determine whether someone has inherited the defective gene believed responsible for the disease. But it requires genetic information from other family members, who are often unavailable.

The new test requires only the person being tested. It involves injecting subjects with a form of sugar attached to a radioactive substance and then measuring the metabolic activity in the brain using a computerized procedure known as positron emission tomography.