Also known as: Two sets of DNA in one person
A young boy presents with rectal bleeding and hallucinations of alien abduction. The team discovers he is a chimera—two embryos that fused in utero—with foreign DNA throughout his body causing intermittent bleeding disorder, hypertensive crises, visual problems, and seizures. Surgery successfully removes the affected tissue from his heart, bone marrow, retina, and brain.
Also known as: Bleeding disorder
Clancy tests positive for Von Willebrand's disease, explaining his intermittent bleeding issues. The bleeding disorder is caused by affected bone marrow cells containing foreign DNA from his chimeric twin.
Also known as: High blood pressure emergency
Clancy experiences multiple episodes of stage-two hypertensive crisis with systolic pressure around 170, causing pulmonary edema. The hypertension is caused by affected myocytes in his heart from the chimeric DNA and paradoxically helps him clot despite his Von Willebrand's disease.
Also known as: Addison's disease
A patient from House's previous case was in a vegetative state but recovered completely after one shot of cortisol, confirming House's diagnosis of Addison's disease. Cuddy had lied to House about this case being wrong as part of a plan with Wilson to make House more humble.
Also known as: Chronic pain
House's chronic leg pain appears to be returning after his ketamine treatment. His team notices he's limping again and favoring his left side. Wilson and Cuddy are concerned the ketamine treatment is failing and that lying to House about his previous case may be causing depression that's preventing him from exercising and rehabilitating properly.