In House M.D., what rare genetic disorder does Thirteen have?

In House M.D., Thirteen has Huntington’s disease.

Remy Hadley, known as Thirteen, learns that she carries the gene associated with Huntington’s disease, a progressive inherited neurological disorder. The diagnosis becomes one of her defining storylines and influences her decisions about relationships, treatment, and the possibility of future disability.

Huntington’s disease is caused by a mutation in the HTT gene and is inherited in an autosomal dominant pattern. A person with an affected parent has a 50 percent chance of inheriting the altered gene. Symptoms can include involuntary movements, changes in mood or behavior, and progressive cognitive impairment, although onset and progression vary.

The show uses Thirteen’s diagnosis to explore ethical and emotional questions rather than treating it as a simple case-of-the-week reveal. The condition is not Wilson’s disease, despite the similar-sounding name; Wilson’s disease is a different inherited disorder involving copper accumulation. Thirteen’s storyline also should not be confused with the unrelated medical diagnoses featured in individual episodes.