What is Huntington's Disease... in 30 seconds?
HD is an autosomal, genetic, neurodegenerative disease that affects your cognition, movement, and behavior. HD can be difficult to visualize so for those who are unfamiliar with it, it has been described as a combination of Parkinson's, Alzheimer's, and ALS all at once, stretched over a 10-20 year (ish) period. There are many nuances and differences in HD in comparison to these more commonly known illnesses, that we will break down further.
Chorea- what's that?
Chorea consists of involuntary, unpredictable jerking movements. This is a distinguishing feature of HD.
What are CAG repeats?
The gene responsible for HD contains a sequence with several CAG repeats (Cytosine, Adenine, Guanine). We all have these CAG repeats in the gene that codes for the huntingtin protein, and a normal amount of repeats is what most of us have. HD is caused by a mutated gene, which means there are too many CAG repeats. For people with HD, they inherit that gene from one of their parents. For a deep dive into genetics, check out our Genetics of HD
That makes sense, I've heard of those. Now I'm ready for the full story.
Huntington’s disease (HD) is a neurodegenerative illness that causes damage to the brain that results in changes in movement, thinking and behavior (psychiatric symptoms). HD is caused by abnormal genes that are present at birth. However, the symptoms don’t start to appear until a person is around 35-50 years old. Once the symptoms start, they will become worse over a 10 to 20 year period before a person sadly passes away.
Much is known about the defective gene that causes HD, but a cure has not been developed yet. Many researchers around the world are working to find ways to slow down the disease or stop the symptoms from starting. In the meantime, there are medical treatments and evidence-based strategies to treat the physical and mental symptoms.
HD is an inheritable disease. If a parent has HD, each of their children has a 50/50 chance of having the abnormal gene and developing the symptoms of HD.
An abnormal HD gene is much longer than usual because of CAG repeats. If the CAG sequence is repeated 40 or more times, a person will develop the symptoms of HD. If they have somewhere between 27-39 CAG repeats, they have a smaller risk of getting the symptoms and passing the disease on to children. If a person has fewer than 27 CAG repeats, they won’t have HD or pass it on.
Okay.. What now?
HD Reach is here to help! On our site you'll find information and resources for genetic testing, symptoms/treatments, guides/strategies for caregivers, ways to connect with other HD families, and so much more.
It's okay to be overwhelmed, contact us and we can help guide you through the storm. Sometimes we have to say "Yikes!" and move on.
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Subtle symptoms may be present decades before diagnosis. -
Of people experience motor symptoms at clinical onset -
Functional abilities diminish as disease becomes more advanced -
Of people with HD experience chorea
