an autosomal recessive genetic disorder characterized by an inability to coordinate voluntary muscle movements (see ataxia) and by the dilation of small blood vessels in the eyes, nose and ears. Initial symptoms may include limb ataxia and truncal ataxia which eventually become so severe that the individual must move in a wheelchair. Other symptoms include slowed speech, the appearance of involuntary movements like intention tremors, and a susceptibility to infection, particularly respiratory infection.