congenital sucrase-isomaltase deficiency (MONDO_0009114) is a disorder of carbohydrate absorption and transport caused by autosomal recessive mutation of the SI gene, characterized by malabsorption of sucrose and maltose. Also known as: CSID, congenital sucrase-isomaltose malabsorption, congenital sucrose intolerance, disaccharide intolerance, genetic sucrase-isomaltose malabsorption, sucrase-isomaltase deficiency.