The function of ENSG00000090402 (SI, sucrase-isomaltase) is as follows. Bifunctional enzyme with both sucrase and isomaltase activities involved in breakdown of dietary starch oligosaccharides in small intestine. The isomaltase domain hydrolazes alpha-1,6-glycosidic linkages in isomaltose. The sucrase domain cleaves the alpha-1,2- glycosidic linkages in sucrose to form glucose and fructose, and contributes to the cleavage of the alpha-1,4-glycosidic linkage in maltose to form two glucose monosaccharides. .