In addition to rare metabolic disorders typically diagnosed in childhood, there are several health conditions considered by many to be absolute contraindications to initiating KDs in adults; these include acute pancreatitis, nephrolithiasis, renal failure, liver failure, congestive heart failure, anorexia nervosa, and concurrent use of SGLT2 inhibitors. The gene discussed is SLC5A2; the disease is nephrolithiasis.