A: Huntington's disease is passed on by a dominant gene, so usually it can be said that if one parent has it then each child has a 50% chance of having it too. So, if neither of your parents have the disease, the odds are that you won't either because you can't pass on something you don't have.
Very occasionally, it's possible to develop Huntington's disease without having a history of it in your family. But this is usually just because one of your parents was never diagnosed with it.
Huntington's disease does not skip generations. Each child of a parent with Huntington's has a 50% chance of inheriting the defective gene. If a child does not inherit the gene, he or she cannot pass it on. If the child does inherit the gene, he or she can pass it on and will develop the disease.
Huntington's disease is a progressive brain disorder caused by a single defective gene on chromosome 4 — one of the 23 human chromosomes that carry a person's entire genetic code. This defect is "dominant," meaning that anyone who inherits it from a parent with Huntington's will eventually develop the disease.
Some facts about genetics and Huntington's
Every child conceived naturally to a parent who has the faulty gene has a 50 % chance of inheriting it and the disease. If both parents have the faulty gene the child has a 75 % chance of inheriting it.
Each child of a parent with HD has a 50 percent chance of inheriting the HD gene. A child who does not inherit the HD gene will not develop the disease, and generally, they cannot pass it on to their children or other future generations.
In the United States, Huntington's disease occurs in about one of every 10,000 to 20,000 people. It affects males and females equally and crosses all ethnic and racial boundaries. Typically, symptoms begin between age 30 and 55.
Onset occurring ≤20 years is classified arbitrarily as juvenile-onset HD (JHD). The youngest symptomatic child documented had an age of onset of 18 months,3 with other children developing symptoms in their teens, meaning that some individuals with JHD may now be in their twenties.
The symptoms usually start at 30 to 50 years of age, but can begin earlier than this (juvenile Huntington's disease) or much later. Once they start, the symptoms usually get gradually worse.
Early symptoms of Huntington's disease vary from person to person. In many cases, they go undetected, and a definite diagnosis isn't made until symptoms have progressed.
It is passed on from parents to children. If a parent has Huntington disease, the child has a 50% chance of developing it. If the child doesn't develop the disease, he or she won't pass it along to his or her children. For 1% to 3% of people with Huntington disease, no family history of the disorder is ever identified.
The future of Huntington's disease management
“The goal is to slow down the course of Huntington's disease, preferably preventing its progression entirely.” Younes indicated there might even be an opportunity to proactively start treatment for people who carry the genetic mutation that causes Huntington's disease.
Genetic Factors
The faulty gene can only be passed on at point of conception. You cannot “catch” Huntington's disease (it is not communicable), and it cannot skip a generation.
See your health care provider if you notice changes in your movements, emotional state or mental ability. The signs and symptoms of Huntington's disease can be caused by a number of different conditions. Therefore, it's important to get a prompt, thorough diagnosis.
DNA is passed down randomly
The DNA you inherit is random. One or both parents may have ethnicities that they didn't end up passing down to you–or they may have passed down only a small portion of a region they have.
Huntington's disease is caused by a faulty gene. Cells in parts of the brain are very sensitive to the effects of the faulty gene. This makes them function poorly and eventually die. A parent with the Huntington's disease gene has one good copy of the gene and one faulty copy.
In 1872, George Huntington gave the first complete description of the disease based on his studies of several generations of one family who exhibited similar symptoms.
Prenatal Diagnosis is the process of testing a baby while in the pregnant uterus to determine if the baby has inherited Huntington's disease (HD) or not. This can be done two different ways: CVS (Chorionic Villus Sampling) is done typically between 10-13 weeks of pregnancy.
The range of disease duration was between 2 and 17 years, the oldest living to age 91.
It is a hereditary, degenerative disease that causes a progressive loss of movement control, thinking abilities, and emotions. Average life expectancy is about 10 to 15 years after diagnosis. Usually, the first signs are declines in school performance. Handwriting and movement become awkward.
The disease is genetic, which means it is inherited from your parents. There is no cure, and it is fatal. People are born with the defective gene that causes the disease. But symptoms usually don't appear until middle age.
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that usually starts in mid-adult life. The clinical disease progresses to death over an average of 20 years.
With dominant diseases like Huntington's Disease (HD), it is usually pretty easy to figure out risks. Generally if one parent has it then each child has a 50% chance of having it too. And if neither parent has the disease, then odds are that none of the kids will either. Huntington's is a dominant genetic disease.