How is Huntington's disease (HD) diagnosed?
Because HD is an inherited condition, the doctor will need to know if anyone else in the family has the disease. The doctor will perform a physical examination of the patient, paying close attention to abnormal movements such as chorea, as well as balance, reflexes and coordination.
In addition, the doctor may order brain imaging tests such as magnetic resonance imaging (MRI) or computed tomography (CT) scans, and blood tests, to see if there are any diseases that may produce changes similar to HD symptoms.
If the blood tests are negative and the doctor feels that the patient has examination findings consistent with HD (usually with a family history), the doctor may consider genetic testing for HD.
The HD genetic test should only be performed after the patient has received thorough counseling, allowing for reflection about the risks and benefits of testing. In the majority of instances, this counseling should be done by a genetic counselor who specializes in HD. In some instances, family members who are well (no obvious symptoms) may want to be tested to know if they carry the abnormal gene. They also should be referred for genetic counseling prior to testing. The genetic test is similar to a routine blood test, but the result may take several weeks to obtain.