Huntington Disease

Huntington disease, formerly called Huntington's chorea (kor-EE-uh), is a rare disease that causes part of the brain to deteriorate. A person with the disease has involuntary and strange movements. It is a genetic disorder, meaning that is inherited by the child from a parent's genes.

Huntington affects the basal ganglia (GANG-lee-a, nerve cell bodies in part of the white matter of the brain). This part of the brain acts as an important pathway for the central nervous system * . Huntington disease causes erratic movements, usually first affecting the face and speech. Memory, reasoning, and speech become affected. Eventually, the abilities to walk, swallow, and take care of oneself are lost.

Males and females are equally affected. A person with Huntington disease usually first exhibits symptoms between the ages of 35 and 50. A person with the disease may live for another 10 to 20 years, but the condition is progressive (becomes worse over time). A less common form of Huntington disease known as early-onset or juvenile Huntington disease begins in childhood or adolescence, usually before the age of 20. Signs of the juvenile form include slow movements, clumsiness, frequent falling, rigidity, slurred speech, and drooling. School performance declines as thinking and reasoning abilities become impaired. Seizures occur in 30 to 50 percent of children with this condition. Juvenile Huntington disease tends to progress more quickly than the adult-onset form; affected people usually live 10 to 15 years after signs and symptoms appear.

A person with Huntington disease may first make unusual or strange facial grimaces and become clumsy. Also, the person may become irritable or forgetful. The person may appear to be drunk even without having consumed any alcohol. The awkwardness that comes from the disease may put the person in danger, for example, by losing her balance while crossing the street.

There is no cure for Huntington disease, but there is medicine to control the erratic movements caused by the disease. This medicine blocks the production of dopamine * in the brain.

Offspring of someone with Huntington disease are advised to seek genetic counseling before deciding whether to have children of their own, as these children also could inherit the disease. A particular blood test can determine whether a person has the gene for Huntington disease.

There was no cure as of 2016 for Huntington disease, but knowing if a person has the gene can influence that person's decision about having children who might develop this disease later in their lives. The test shows whether the person has the gene that causes the disease. Sometimes people who are at risk may not want to know if they have the gene, and they take the chance of having children before the onset of the disease is noticed. They feel that knowing they have the gene will make it impossible for them to live a normal life.

See also Genetic Diseases: Overview

* central nervous system (SEN-trul NER-vus SIS-tem) is the part of the nervous system that includes the brain and spinal cord.

* dopamine (DOE-puh-meen) is a neurotransmitter in the brain that is involved in the brain structures that control motor activity (movement).