Huntington's disease is also known as Huntington’s chorea, chorea major or HD. It is named after the physician George Huntington who described it in 1872. This is a genetic neurological disorder the characteristic features of which are abnormal body movements called chorea accompanied by a lack of coordination. Huntington’s disease is known to affect certain aspects of behavior and may result in various mental disabilities.

In 1993, the gene responsible for the development of this debilitating disorder was discovered making it one of the first inherited genetic disorders for which an accurate test can be performed. This has made it possible for large scale research to be conducted on the characteristics HD shared with various other neurological disorders such as Alzheimer’s disease. The gene causing the disorder is dominant and may be inherited from a single parent. Evidence varies 3 to 7 percent per 100,000 people of Western European descent down to 1 per 1,000,000 of Asian and African descent. The onset of physical symptoms occurs mainly in the late forties or early fifties. If the symptoms become prominent before a person is twenty, the condition is known as Juvenile Huntington’s disease.

Etiology:

HD is one of the many polyglutamine diseases caused by a trinucleotide repeat expansion in the Huntington’s gene which usually codes for Huntington protein of neuron cell death in select areas of the brain resulting in the production of mutant Huntingtin. This accelerates the death rate of neuron cells affecting neurological functions. The loss of neurons is not fatal but the complications induced by the symptoms reduce the life expectancy of the patient.

Symptoms of Huntington’s disease:

The primary symptoms of this disorder include personality changes and decreased cognitive abilities. They are characterized by irritability, anger, depression, difficulty in making decisions, lack of judgment, difficulty in learning new skills and information and the ability to retrieve information.

Physical symptoms of the disorder may include problems related to balance, gaucheness and involuntary facial gestures such as grimacing. Other symptoms include:

• Sudden and jerky involuntary movements throughout the body
• Problems in maintaining balance and coordination
• Difficulty in shifting the gaze without movement of the head
• Slurred speech
• Problems with swallowing
• Dementia