Disaccharidase deficiencies of lactase, sucrase-isomaltase (palatinase), and maltase-glucoamylase may present with flatulence, bloating, and diarrhea, with 46.7% of adults presenting with gastrointestinal symptoms having at least 1 disaccharidase deficiency.59 The gene discussed is MGAM; the disease is hyperinsulinemic hypoglycemia, familial, 4.