Trehalose is a disaccharide found in mushrooms, algae, and insect hemolymph; mushrooms and products containing baker's yeast are thus the only sources of trehalose in the human diet. The high concentration of trehalose in cryptobiotic plants is responsible for their remarkable ability to go through cycles of desiccation and rehydration without injury. This led to interest by the food industry in the addition of trehalose to foodstuffs to improve the longevity and quality of dried food. However, ingestion of a disaccharide in an individual who cannot digest it results in osmotic diarrhea, abdominal pain, and increased rectal flatulence (summary by Murray et al., 2000). Isolated trehalose intolerance due to deficiency of trehalase (TREH; 275360) is probably rare in adult white Americans (Welsh et al., 1978), but has been estimated at 8% in Greenlanders (Gudmand-Hoyer et al., 1988). [from OMIM]