By: Hannah Devlin || Neuroscience | The GuardianHuntington’s patient Peter Allen and his siblings – who also carry the gene – watched their mother and grandmother slowly die from the disease. But a new trial has given the family a glimmer of hopeHuntington’s has blighted Peter Allen’s family for generations. He watched his mother, Stephanie, slowly die from the disease and before that his grandmother, Olive, fell victim to the same illness. At 51 years old, Peter is the first of his generation to show signs of the illness, but his sister, Sandy, and brother, Frank, know they are also carrying the gene. The onset of Huntington’s is insidious. Psychological changes typically come first – tiredness, mood swings, apathy and anger. Four years ago, Peter was formally diagnosed as symptomatic when he began suffering anxiety and panic attacks so severe he would become convinced that he couldn’t swallow. In retrospect, the depression he suffered in his thirties may have been an earlier manifestation of changes happening his brain. Huntington’s disease is a congenital degenerative condition caused by a single defective gene. Most patients are diagnosed in middle age, with symptoms including mood swings, irritability and depression. As the disease progresses, more serious symptoms can include involuntary jerky movements, cognitive difficulties and issues with speech and swallowing.