Huntington's disease, a neurodegenerative disease, affects 30.000 Americans and is incurable and fatal. But a new discovery about how cells repair DNA indicates a possible way to stop or slow the onset of the disease process. The study was founded by the National Institute for Health (NIH). "What happens often, research touch with a biological process - in this case the enzymes involved in DNA repair - leads to new discoveries about this illness and ways to prevent and deal with them." said Dr. Elias A. Zerhouni, NIH director.



The study was published on April 22, as an advanced online publication in the Nature journal and was led by Dr. Cynthia T. McMurray, professor of pharmacology at the Mayo Clinic in Rochester, Minnesota.Unlike other genetic diseases, symptoms of Huntington's disease usually appear not only to middle aged people, which put scientists on thoughts on the cause of the onset of symptoms and determine whether or not they can be countered, or at least slowed down.

Patients with this disease have a version of a gene called Huntington that carries an extra segment with a certain sequence of repetitive units. If the segment is too large, erroneous gene produces a protein with brain damaging effect. "Huntington's disease is a progressive disease, but no one knows exactly why." McMurray says. "Our work supports the idea of disease progresses when the extra segment increased during non-dividing cells such as neurons."

McMurray's study shows that the inserted segment increased when the cell tries to remove oxidative lesions are caused by byproducts of oxygen breathing. DNA repair enzymes initially manage to repair oxidative damage, but over time, increased the number of lesions make the capacity of the system outdated. Oxidative lesions also accumulate in people who have Huntington's disease, but the absence of extra segments on the Huntington gene does not lead to manifestations. Although scientists have hypothesized that oxidative lesions play an important role in Huntington's disease for a long time, the appropriate place of injury is still unknown.

"No one has yet linked these indicators with each other." McMurray says. To show that further segments grow in time, the researchers inserted the human genome in mice, which contained a Huntington gene with an inserted segment and big enough for the disease to be manifest in humans. Over several months - when mice were much older - researchers analyzed gene and found that the segment is high.

Because Huntington's disease affects the mind, body, and emotions, symptoms often mimic other conditions. The general symptoms of Huntington’s disease in early stages can include poor memory; difficulty making decisions; mood changes such as increased depression, anger or irritability; a growing lack of coordination, twitching or other uncontrolled movements; difficulty walking, speaking, and/or swallowing. The order in which symptoms develop will vary from person to person. This disease generally develops in adult people.