TREH (Trehalase): TREH is a gene that encodes the enzyme trehalase, which is involved in breaking down trehalose, a disaccharide sugar. Trehalase plays an important role in carbohydrate metabolism, especially in the gut where trehalose is hydrolyzed. Deficiencies in trehalase activity can cause trehalose intolerance, leading to gastrointestinal symptoms after trehalose consumption.