For individuals who are at risk of carrying the HD gene, testing can be performed before symptoms occur. Information from brain scans such as computed tomography (CT), electroencephalography (EEG) and magnetic resonance imaging (MRI) may be part (magnetic resonance imaging) and may be reviewed as part of the diagnosis.
The most effective and accurate method of testing for HD—called the direct genetic test—counts the number of CAG repeats in the HD gene, using DNA taken from a blood sample. The presence of 36 or more repeats supports a diagnosis of HD.
People can start to show the symptoms of Huntington's disease at almost any age. Most will develop problems between the ages of 30 and 50. The condition gradually gets worse for around 10-25 years, until the person dies.
Pre-symptomatic testing for Huntington's disease, also known as predictive testing, is a bit more complicated than diagnostic testing. Pre-symptomatic testing happens when people who know they may be at risk for HD but who do NOT have symptoms seek testing to learn whether they will get HD in their lifetimes.
Lots of people at risk of Huntington's disease decide they'd rather not know until any symptoms appear. If you do want to know, ask your GP for a referral to a genetic counsellor. You'll have several appointments with the counsellor. It's only done once all the benefits and risks have been explained.
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.
Medical imaging techniques, such as computerized tomography (CT) and magnetic resonance imaging (MRI) can reveal atrophy of the caudate nuclei, which is observed in the early stages of Huntington's disease.
In order to receive a diagnosis, you will need to obtain a referral from your GP to see a Huntington's disease specialist. The initial consultation may include: Discussion of family history. Your current knowledge of Huntington's disease.
Among X‑linked conditions, McLeod syndrome can mimic the clinical features of HD. Although less frequently, sporadic conditions, such as tardive dyskinesia and non-Wilsonian hepatolenticular degeneration, can also mimic HD.
Overview. Huntington's disease is a rare, inherited disease that causes the progressive breakdown (degeneration) of nerve cells in the brain.
Average age of onset is about 40 years old, with a range from childhood to the eighth decade [2,3]. It has been suggested that older onset patients are more likely to present with motor manifestations, and younger patients with psychiatric/behavioral manifestations [4].
You're usually only at risk of developing it if one of your parents has or had it. Both men and women can get it. If a parent has the Huntington's disease gene, there's a: 1 in 2 (50%) chance of each of their children developing the condition – affected children are also able to pass the gene to any children they have.
HD is a rare, adult-onset, autosomal dominant, progressive neurodegenerative disease. George Huntington (Figure 1) was the first person to provide a comprehensive description of adult-onset HD in 1872; he was only 22 years old at the time.
Early signs and symptoms can include irritability, depression, small involuntary movements, poor coordination, and trouble learning new information or making decisions. Many people with Huntington disease develop involuntary jerking or twitching movements known as chorea.
Although anyone can develop HD, it tends to run in people of European descent (having family members who came from Europe). But the main factor is whether you have a parent with HD. If you do, you have a 50% chance of also having the disease.
Parkinson's disease and Huntington's disease are both model diseases. Parkinson's disease is the most common of several akinetic-rigid syndromes and Huntington's disease is only one of an ever growing number of trinucleotide repeat disorders.
Although a diagnosis of HD is largely based on clinical symptoms, the gold standard for diagnosis is genetic testing.
It is possible to be tested for Huntington's disease before any symptoms appear, if there is a known family history of the disease. However, a diagnosis can be difficult if there are between 36 to 40 CAG repeats, as the disease may or may not develop in the person.
A positive test result means you do carry the faulty HD gene. Due to the genetic nature of HD, your test results may impact others in your family who are at risk. If you have a positive test result, it means that your parent also has the faulty gene, and your siblings may as well.
Currently, there are no treatments available for Huntington's disease that change the course of the disease.
Typically, HD progresses for 10 to 30 years. Most people with HD die from complications related to the disease. There is no cure for HD, and current medications can only relieve its symptoms, not slow or delay the progression. If Huntington's disease runs in your family, you may want to have genetic testing.
In early stage HD, individuals are largely functional and may continue to work, drive, handle money, and live independently. Symptoms may include minor involuntary movements, subtle loss of coordination, difficulty thinking through complex problems, and perhaps some depression, irritability, or disinhibition.