Due to the incredible collaborative efforts of Huntington’s disease patients who donated their DNA samples and the Huntington’s Disease Collaborative Research Group, the mutated Huntingtin gene was discovered in 1993. The discovery of the gene now meant we now had scientific evidence that if you inherit the mutated gene, you will develop Huntington’s disease. As a result, in 1993 the community had access to predictive testing that would identify whether you inherited the faulty Huntingtin gene, and would one day, exhibit symptoms of Huntington’s disease. The process of predictive testing includes extracting your DNA from a blood sample to identify whether you are carrying the mutated Huntingtin gene. However, the test cannot determine when symptoms will begin or how severe symptoms are likely to be.

The testing process usually includes the following steps but can vary in the number of appointments:

• An initial appointment with a genetic counsellor during which you may discuss the history of Huntington’s disease in your family, the genetics of Huntington’s disease, the reason that you’re seeking testing, and potential impacts of any test result.
• A second appointment, which will include a blood test and potentially a neurological examination test if you decide to go ahead with one.
• Another appointment once your test results are ready. The time between the initial blood test and receiving your results is generally 6 to 8 weeks. 
• Follow up counselling support may also be required and is recommended by the genetic counsellor regardless of your test results.

Genetic counselling is a supportive fact-based process that walks you through the genetics of Huntington’s disease, and also can explore your family history with you. In addition, genetic counsellors can assist you to explore IVF/PGD family planning options.

According to international guidelines, if you are 18 years of age or older and have a blood relative who has been diagnosed with Huntington’s disease, you are eligible for the genetic test. If you are under 18 years of age and have questions about testing, please get advice from your local Huntington’s disease association. However, in most cases, genetic testing is not legally permitted for minors even with parental consent.