A medical workup for delirium revealed normal complete blood count, a comprehensive metabolic panel with mildly elevated transaminases [aspartate aminotransferase (AST) 94 U/L; alanine transaminase (ALT) 72 U/L], and a noncontrast computed tomogram of the brain with mild diffuse volume loss greater than expected for her age. The gene discussed is GPT; the disease is delirium.