Topic: Huntington Chorea
Subject: Medicine
A patient previously diagnosed with Huntington chorea (HC) comes for a family planning consult with his wife. He states that his father had the disease and his mother was unaffected. They ask you what is the likelihood having a son with this condition?

Huntington chorea (HC), is an inherited disease characterized by choreiform movements and progressive dementia. It is inherited as an autosomal dominant disorder. There is a 50% chance of the man passing the disease to his child. There is a 50% chance of having a son. 0.5x0.5=0.25 = 25% Therefore, there is a 25% chance of the man passing the disease to his son.