Gene Therapy & Huntington's Disease

While there is no cure for the degenerative brain disease known as Huntington's Disease, there are some treatment options that can make life more comfortable for the patient and his family. Medications are currently used to treat the effects of Huntington's Disease, but gene therapy is being researched in the hopes that it may be able to restore brain function and perhaps reverse the effects of the disease.

What is Huntington's Disease?

• Huntington's Disease, or HD, is a brain disease that causes the degeneration of genetically programed neurons. Degeneration occurs in certain areas of the brain, particularly in those areas that control intelligence, emotional responses and movement.
  The age of onset and progression of Huntington's Disease can vary from one person to another.

Causes & Symptoms

• The disease is typically passed on from parent to child via a mutation of a normal gene. Approximately 30,000 people in the United States are affected by Huntington's Disease, and children of HD parents have a 50 percent chance of inheriting the HD gene. Inheriting the gene means that an individual will develop the disease sooner or later.
  Early symptoms of Huntington's Disease are depression, mood swing, irritability, and trouble with driving, remembering facts, learning new things and making decisions. As the disease takes hold and progresses, the ability to concentrate on an intellectual task increases in difficulty. An HD person may also have difficulty with swallowing and feeding herself.
  As of October 2009, there is no cure for Huntington's Disease. There is no way to reverse the course of it or stop it entirely. However, medication and gene therapy can help to control many of the problems associated with the disease.

What is Gene Therapy?

• Gene therapy is the process of inserting specific genes into a individual's cells in order to treat a disease. Gene therapy is typically used to treat hereditary diseases, such as Huntington's Disease. Its purpose is to provide a defective or degenerated gene with alternative genes that are still fully functional. As of October 2009, gene therapy is still in the very early stages of development, though it has shown success with some hereditary diseases.

Treating Huntington's Disease with Gene Therapy

• Gene therapy is appealing for Huntington's Disease patients because of its potential to replace dying neurons with healthy ones, thus improving and even restoring brain function. Animal and human pilot studies have shown success with the use of embryonic stem cells. In the studies, transplanted cells not only survived, but flourished in their new environment by growing and establishing connections with other neurons. However, the use of human embryonic cells is controversial, and raises ethical questions. It is suggested by some that HD researchers will need to find another source of neuronal cells.

Other Treatment Options

• While gene therapy continues to be researched, physicians and medical teams are using medication to help manage the effects of Huntington's Disease. Because depression, delusions, violent outbursts and mood swings are common side effects of the disease, anti-psychotic drugs, anti-depressants, tranquilizers and mood stabilizers are used. These types of medications often have significant side effects, so most physicians prescribe the lowest possible dose.
  Because HD patients can have trouble with meals due to movement problems, difficulty swallowing and jaw clenching, it is recommended that food be cut into small pieces, or softened or pureed. Patients should avoid dairy products because of their tendency to increase mucus secretions. Vitamins and nutritional supplements are recommended for patients who are having difficulty consuming enough calories.
  As the disease progresses, bendable straws for drinking may be necessary, and feeding tubes might also need to be considered.
  Because there is no cure for Huntington's Disease, it will continue to progress, and will usually run its full course in 10 to 30 years. In the final stages of the disease a patient will often become bedridden, and will most likely die from heart failure, pneumonia or a related complication. (See Reference 4)