It is passed from parent to child in an autosomal dominant manner, meaning you need only one copy of the gene to inherit the disease. This is in contrast to an autosomal recessive disorder which requires two altered genes to inherit the disorder or an altered gene from each parent. If you do not have the HD gene, you can not pass it on to your children and they can not pass it on to their children. The HD gene is present from birth, but the age of onset is usually in the third or fourth decade of life. While this is the most common time for symptoms to appear, there have been reports of onset as young as 2 and as old as 80.
Symptoms begin gradually and progress over time.
Because of this, quality care and attention to changes in the affected individual's condition can often prevent or minimize complications and increase quality of life. It is commonly seen as restless, wriggling movements of the fingers or toes in the early stages of the disease. Movements tend to become larger over time and can involve the face, arms, trunk and legs. Chorea may appear more pronounced when an individual is under stress or experiencing an extreme of emotion. Rigidity or muscle stiffness and slowness may also be present.