<unk>  can be caused by genetic mutations in which both parents must contain this gene for the child to carry the disease (so-called primary<unk> .<unk>  can also be caused by irritable bowel syndrome, aging, or small intestine disease (secondary<unk> . There are specific tests used to help determine if a person has<unk> . The most accurate test is the enzyme activity determination, which is done by biopsying the small intestine. This test is a diagnostic for GSID. Other tests which can aid in the diagnosis of GSID but which are not truly diagnostic for the disease are the<unk>  breath test, and a genetic test which tests for the absence of certain genes which are thought to be responsible for GSID.<unk>  (also called saccharose) is a disaccharide and is a two-sugar chain composed of glucose and fructose which are bonded together. A more familiar name is table, beet, or cane sugar. It was believed that most cases of<unk>  were due to an autosomal recessive, genetic, metabolic disease. Based on new data patients with heterozygous and compound heterozygous genotypes can have symptom presentation as well. GSID involves deficiency in the enzyme<unk> -isomaltase, which breaks the bond between the glucose and fructose molecules. When disaccharides are consumed, they must be broken down into monosaccharides by enzymes in the intestines before they can be absorbed. Monosaccharides, or single sugar units, are absorbed directly into the blood. A deficiency of<unk>  may result in malabsorption of sugar, which can lead to potentially serious symptoms. Since<unk> -isomaltase is involved in the digestion of starches, some GSID patients may not be able to absorb starches as well. It is important for those with<unk>  to minimize<unk>  consumption as much as possible. Dietary supplements or medications may be taken as a substitute for the missing enzyme or to introduce healthy bacteria into the immune system.
Sucrose intolerance
Lactose intolerance
Fructose malabsorption
Glucose-galactose malabsorption
Saccharopinuria
Hereditary fructose intolerance
Bile acid malabsorption
Chyluria