Huntingtоn's diseаse (HD) is а chrоnic, inherited diseаse that causes nerve cells in the brain tо deteriorate and die. It affects areas of the brain that control movement, thinking, and other functions. There is no cure, but treatments can help manage symptoms. Huntington's disease (HD) follows traditional genetics, and is an autosomal dominant disorder. Based on the image below regarding HD, answer the questions below. What do the filled in circles represent?