Since HD is believed to have major origins in Northern Europe, 2 it is not surprising that populations of Northern European descent are recorded as having the highest prevalence of HD in theworld.
Huntington's disease is currently found in many different countries and ethnic groups around the world. The highest frequencies of HD are found in Europe and countries of European origin, such as the United States and Australia. The lowest documented frequencies of HD are found in Africa, China, Japan, and Finland.
o How many Australians have Huntington's disease? The best available published evidence of relevance to Australia suggests a prevalence rate of 8.4 per 100,000 people. This indicates that with a current population of 25.7 million people in Australia1, there is currently around 2,160 people with a diagnosis of HD.
Huntington disease affects an estimated 3 to 7 per 100,000 people of European ancestry. The disorder appears to be less common in some other populations, including people of Japanese, Chinese, and African descent.
Other countries where Huntington's is particularly prevalent include Ireland (10.6 per 100,000); Norway (6.7); Italy (6.35); Australia (6.3); Denmark (5.8); Great Britain (5.4); Slovenia (5.2); and Sweden (4.7).
The highest risk HD haplotypes (A1 and A2), are absent from the general and HD populations of Japan, and therefore provide an explanation for why HD prevalence is low in Japan. Such differences, therefore, suggest that the HTT allele originated independently in these three regions.
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.
It affects males and females equally and crosses all ethnic and racial boundaries. Typically, symptoms begin between age 30 and 55. Children of parents with Huntington's disease have a 50 percent chance of inheriting the HD gene.
Nine patients have died, and seven have been lost to follow up. The range of disease duration was between 2 and 17 years, the oldest living to age 91.
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.
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.
Because Huntington's is a genetic disease, you can't do anything to prevent it if you have inherited it. If you have a history of Huntington's disease in your family, you may wish to have genetic counseling before having children of your own.
While the cause of the disease is known — a single mutated gene — there is no cure. “Our plan is to conduct human clinical trials that deliver stem cells to replace damaged brain cells, reducing levels of harmful proteins that build up in the brains of Huntington's disease patients.”
It's possible to develop HD even if there are no known family members with the condition. Around 10% of people with HD don't have a family history.
In addition to the symptoms of the adult disease, early signs in children may include seizures and stiffness. Children with JHD most often inherit the disease from their fathers.
Huntington's disease is inherited in an autosomal dominant fashion. The probability of each offspring inheriting an affected gene is 50%. Inheritance is independent of gender.
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.
They may lack inhibition, and do or say things that one would normally find embarrassing. People with Huntington's may also be less able to control their emotions, possibly leading to outbursts of screaming, swearing, slamming doors, hitting walls, or the like. Patterns of behavior can change as the disease progresses.
The most painful conditions in Huntington's, said Achterberg, are limb pain, headache, abdominal pain and fractures. “I think we should do more work in validation of pain tools, including observational pain instruments,” he said. “And for clinicians, I suggest you be especially aware of abdominal pain.”
Weight loss can make symptoms worse and weaken the patient's immune system, making them more vulnerable to infections and other complications. Huntington's disease itself is not usually fatal, but it can lead to choking, pneumonia, or other infections that can lead to death.
Symptoms of Huntington's disease usually develop between ages 30 and 50, but they can appear as early as age 2 or as late as 80. The hallmark symptom of Huntington's disease is uncontrolled movement of the arms, legs, head, face and upper body.
The worldwide service-based prevalence of HD, based on a meta-analysis (n = 13 studies), was 2.71 per 100,000 (95% CI: 1.55-4.72). Eleven studies were conducted in Europe, North American, and Australia, with an overall prevalence of 5.70 per 100,000 (95% CI: 4.42-7.35).