is a metabolic condition in which the body is not able to convert trehalose, a disaccharide found in mushrooms, algae and insects, into glucose. Individuals with this deficiency experience vomiting, abdominal discomfort and diarrhea after eating foods containing trehalose. Studies suggest that this condition is very rare in white Americans, very frequent in Greenland natives (where it has been reported in 8% of the population), and not infrequent among Finns. However, since ingestion of large quantities of foods containing trehalose in not common, the real frequency in unknown. Most cases appear to be inherited in an autosomal recessive manner. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.