How common is the Genetic Disorder: According to the NIH, “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” (“Huntington’s Disease Frequency”). If you have a parent that has or had Huntington's Disease, you would have a 50% chance of having it. Then, your children would have a 25% chance (“Huntington’s disease frequency ”)
According to Huntington’s NSW Act, it’ hard to keep track of how common HD is. But it’s more common in Western countries. In some Western European countries, HD is abnormally common. In Lake Maracaibo, Venezuela, Huntington’s Disease affects roughly 700 per 100,000 people. In Australia over 1,800 people struggle with HD. And about 9,000 have a chance of having it. (How Common Is Huntington’s Disease (HD))