Thoroughly modern medicine.

Personalized medicine is receiving increasing attention in the medical literature and lay press as one way to optimize therapy and reduce complications of treatment for almost any disorder. However, understanding the systemic complexities necessary to implement the ambitious goals of personalized medicine is unlikely to arise from the study of common disorders. Rather, dissecting out the individual components to therapeutic response is far more feasible with defined disorders of known cause. Inborn errors of metabolism offer an attractive opportunity to better define the hyperbole surrounding development and institution of personalized medicine.