$Unique_ID{BRK03774} $Pretitle{} $Title{Glucose-Galactose Malabsorption} $Subject{Glucose-Galactose Malabsorption Carbohydrate Intolerance Complex Carbohydrate Intolerance Irritable Bowel Syndrome Lactose Intolerance Crohn's Disease Galactosemia} $Volume{} $Log{} Copyright (C) 1990 National Organization for Rare Disorders, Inc. 749: Glucose-Galactose Malabsorption ** IMPORTANT ** It is possible that the main title of the article (Glucose-Galactose Malabsorption) is not the name you expected. Please check the SYNONYM listing to find the alternate names and disorder subdivisions covered by this article. Synonyms Carbohydrate Intolerance Complex Carbohydrate Intolerance Information on the following diseases can be found in the Related Disorders section of this report: Irritable Bowel Syndrome Lactose Intolerance Crohn's Disease Galactosemia General Discussion ** REMINDER ** The information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section of this report. Glucose-Galactose Malabsorption (carbohydrate intolerance) is a genetic disorder characterized by the small intestine's inability to transport and absorb glucose and galactose (sugars which can be broken down no further, or monosaccharides). Glucose and galactose have almost identical chemical structures, and normally the same transport enzyme provides them with entry into specialized cells in the small intestine where they are absorbed and transferred to other cells. At the present time, this transport enzyme has not been identified. However it is known to be defective in individuals with glucose-galactose malabsorption. The glucose and galactose which have not been absorbed through the specialized cells of the small intestine are then poorly absorbed much further along in the intestine. This abnormal absorption may interfere with other intestinal absorption processes. Symptoms Symptoms of glucose-galactose malabsorption in children may include diarrhea, dehydration and failure to gain weight. There may also be sugar in the stool after eating any dietary carbohydrate, as all carbohydrates contain either glucose or galactose. There is usually no rise in blood sugar after eating. If untreated, a child may eventually show severe malnutrition or dehydration. In adults, symptoms of glucose-galactose malabsorption may include bloating, nausea, diarrhea, abdominal cramps, rumbling sounds caused by gas in the intestine (borborygmi) and excessive urination. Causes Glucose-galactose malabsorption is inherited as an autosomal recessive trait. Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother. In recessive disorders, the condition does not appear unless a person inherits the same defective gene for the same trait from each parent. If one receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will show no symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is twenty-five percent. Fifty percent of their children will be carriers, but healthy as described above. Twenty-five percent of their children will receive both normal genes, one from each parent, and will be genetically normal. Affected Population Glucose-galactose malabsorption is an extremely rare disorder. There are no statistics available on whether it affects males or females more frequently, nor whether certain ethnic groups are affected more often than others. Related Disorders Symptoms of the following disorders can be similar to those of glucose- galactose malabsorption. Comparisons may be useful for a differential diagnosis: Irritable Bowel Syndrome, also called spastic colon, is a disorder involving the muscles of the small intestine, which fail to ingest food at the proper rate. Overly rapid ingestion of food results in diarrhea, and slow ingestion results in constipation. Symptoms include abdominal pain, erratic bowel movements, variation in stool consistency, bloating, flatulence, nausea, headache, fatigue, depression, anxiety and difficulty concentrating. (For more information on this disorder, choose "Irritable Bowel Syndrome" as your search term in the Rare Disease Database). Lactose Intolerance is a disorder characterized by a lack of the enzyme lactase which normally breaks down the sugar in milk known as lactose, into simpler sugars. The unabsorbed lactose remains in the intestine, causing symptoms of diarrhea, bloating, cramping pain, nausea and flatulence. People with this disorder must avoid milk and milk products, but can eat other carbohydrates. (For more information on this disorder, choose "Lactose Intolerance" as your search term in the Rare Disease Database). Crohn's Disease is a chronic inflammatory disorder which affects the large intestine. Symptoms may include chronic diarrhea, abdominal pain, fever and weight loss. (For more information on this disorder, choose "Crohn's Disease" as your search term in the Rare Disease Database). Galactosemia is an inherited disorder involving the conversion of galactose to glucose. Symptoms in children may include vomiting, lack of appetite, jaundice and neurological problems. (For more information on this disorder, choose "Galactosemia" as your search term in the Rare Disease Database). Therapies: Standard Treatment of glucose-galactose malabsorption requires the elimination of all dietary carbohydrates, including milk and milk products which contain the sugar lactose. Lactose is broken down further into glucose and galactose. Fructose, which is a sugar absorbed differently than either glucose or galactose, may be substituted as a source of carbohydrate calories. Some patients will tolerate the sugar sucrose since it is partially composed of the easily absorbed fructose. Therapies: Investigational This disease entry is based upon medical information available through January 1990. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on Glucose-Galactose Malabsorption, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 National Digestive Diseases Information Clearinghouse Box NDIC Bethesda, MD 20892 (301) 468-2162 For genetic information and genetic counseling referrals: March of Dimes Birth Defects Foundation 1275 Mamaroneck Avenue White Plains, NY 10605 (914) 428-7100 Alliance of Genetic Support Groups 35 Wisconsin Circle, Suite 440 Chevy Chase, MD 20815 (800) 336-GENE (301) 652-5553 References MENDELIAN INHERITANCE IN MAN, 8th ed.: Victor A. McKusick; Johns Hopkins University Press, 1986. Pp. 957. THE METABOLIC BASIS OF INHERITED DISEASE, 5th Ed.: John B. Stanbury, et al., eds.; McGraw Hill, 1983. Pp. 1729-1740. INTERNAL MEDICINE, 2nd Ed.: Jay H. Stein, ed.-in-chief; Little, Brown and Co., 1987. Pp. 140, 880. THE MERCK MANUAL, Volume 1, 14th Ed.: Robert Berkow, M.D., ed.-in-chief; Merck Sharp & Dohme Laboratories, 1982. Pp. 796-797. GLUCOSE-GALACTOSE MALABSORPTION: DEMONSTRATION OF SPECIFIC JEJUNAL BRUSH MEMBRANE DEFECT. I.W. Booth et al.; GUT (December, 1988; issue 29(12): Pp. 1661-1665.) COMPLEX CARBOHYDRATE INTOLERANCE: DIAGNOSTIC PITFALLS AND APPROACH TO MANAGEMENT. J.D. Loyd-Still et al.; J PEDIATR (May, 1988: issue 112(5): Pp. 709-713.)