Huntington's Disease Cause and Risk Factor
Having a parent with Huntington's is the risk factor. A child of an affected parent has a 50% chance of inheriting the disease.
The genetic mutation that occurs in gene IT-15, located on chromosome 4, alters the huntington protein, which is present in all human beings, and causes Huntington's disease. How the mutation of gene IT-15 alters the function of the protein is not well understood.