Huntington’s disease is a family disease. Though everyone is born with the huntingtin gene, the disease is caused by an abnormal copy of the gene that is passed from parent to child. Only a person who is born with the abnormal gene can get the illness and pass it on to their children. Every person who carries the abnormal gene will eventually develop symptoms if they live long enough.
Soon after the HD gene was identified in 1993, a specific gene test was developed which allows a person to find out if they carry the abnormal HD gene and will someday develop the disease. While the test is very accurate, it cannot determine when the symptoms of the disease will begin or how severe the symptoms will be. People without symptoms of HD who test positive for the gene may remain unaffected for many years.
People at-risk for the disease face a difficult choice about genetic testing for HD, given the current absence of an effective treatment or cure. Many people see no benefit in knowing that they will someday develop the disease. Others want an end to uncertainty so that they can make informed choices about the future. The decision whether to test or not is intensely personal and there is no “right” answer.
The Huntington’s Disease Society of America recommends that at risk individuals who are considering genetic testing do so at a genetic testing center that follows the HDSA guidelines. Testing procedures at these centers involves sessions with professionals who are knowledgeable about HD and the local services available. It may take several weeks to receive the results once the genetic test is complete.
Genetic testing for children is typically prohibited before the age of 18, as the child may not understand the full implications of testing and may be vulnerable to pressure from others. However, a child under the age of 18 may be tested to confirm a diagnosis of juvenile onset HD after a thorough neurological exam.
If you have questions, or need further information, please contact our National Helpline at 800-345-HDSA. For a listing of HDSA Genetic Testing Centers CLICK HERE.
For families wishing to have a child who does not have the gene that causes HD, there are a few options. Pre-implantation genetic diagnostic (PGD) testing can be used with In Vitro Fertilization (IVF) to make sure that any fertilized egg implanted does not have the abnormal gene. This can be done without informing the at-risk patient whether or not they have the gene that causes HD. If a woman is already pregnant, she can receive testing for the fetus with a chorionic villus biopsy at 10-11 weeks or via amniocentesis at 14-18 weeks.
If you have questions, or need further information, please contact our National Helpline at 800-345-HDSA.
For a listing of HDSA Centers of Excellence CLICK HERE.