Define Huntington Disease
Huntington disease, commonly known as Huntington’s, usually occurs in middle age and is a neuro-degenerative genetic disorder. It occurs more often in people of Western European descent than in people of Asian and African heritage. Among the best-known victims of the disease was folk singer Woody Guthrie, who died in 1967 after suffering from the illness for 13 years.
Huntington’s disease was first described in an 1842 letter in Robley Duglinson’s “Practice of Medicine.” Before that time, those who suffered from the disease were often accused of being possessed by spirits or of being witches. They were often exiled. By 1846, Charles Gorman noticed that the symptoms associated with the disease seemed to affect many people in particular regions. Johan Christian Lund produced the first description of the illness while working at Jefferson Medical College in 1860, with George Huntington making the first complete description in 1872.
Huntington’s disease is caused by a mutation of a specific gene. This gene, known at the Huntingtin gene, provides genetic code for the protein huntingtin. The mutation causes different forms of the protein that damage specific areas of the brain. The Huntingtin gene, when mutated, is dominant and the disease results when either of your Huntingtin genes is mutated. If your parent has Huntington’s disease, you have a 50 percent change of inheriting the gene, which always results in the disease if you live long enough to develop the illness.
The primary symptom of Huntington’s is chorea. Chorea, also spelled choreia, is a condition that causes involuntary movements. The first symptoms to be noted are usually lack of coordination and an unsteady gait when walking. As the disease progresses, chorea begins to present itself, resulting in jerky body movements. Along with the chorea, there is a decline in mental abilities and an increase in behavioral and psychiatric issues. Complications from pneumonia, heart disease or physical injury usually result in the condition being fatal within 20 years of the onset of symptoms.
When Huntington’s disease symptoms manifest themselves, diagnosis is often made based on the physical symptoms. Genetic testing may be used to confirm the diagnosis, especially if there is no family history of the disease. MRI and PET scans may be used to determine if there have been changes in the brain’s activity. The diagnosis is most often made by a neurologist who will ask questions about the patient’s personal, family and medical history before ordering additional diagnostic testing.
Huntington’s disease cannot be cured. However, there are treatments that help patients to manage their symptoms and that reduce the severity if the disease. Tetrabenazine is often prescribed to reduce chorea, and was approved for this use in the United States in 2008. Neuroleptics and benzodiazepines may also be prescribed for this purpose. Psychiatric medications, such as SSRIs and mirtazapine, are often prescribed for accompanying psychiatric symptoms. Physical and speech therapies are also beginning to be used in helping victims of Huntington’s manage their symptoms.