National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Glucose-galactose malabsorption



Other Names:
Glucose galactose malabsorption deficiency; Carbohydrate intolerance of glucose galactose; Complex carbohydrate intolerance; Glucose galactose malabsorption deficiency; Carbohydrate intolerance of glucose galactose; Complex carbohydrate intolerance; Monosaccharide malabsorption; GGM See More
Categories:

Glucose-galactose malabsorption (GGM) is a genetic condition in which the sugars glucose and galactose cannot be properly absorbed by the body. Infants with GGM develop severe diarrhea resulting in life-threatening dehydrationacidosis, and weight loss in the first few weeks of life. GGM is caused by mutations in the SLC5A1 gene and is inherited in an autosomal recessive manner. This gene normally makes a special protein which helps the two sugars cross through the cell membranes of the epithelial cells lining the small intestine and special tubes in the kidneys. When the protein is missing, the cells cannot take in the glucose and galactose needed by the body.[1] 

Diagnosis of glucose-galactose malabsorption (GGM) is made by the early onset of severe diarrhea, ruling out infections, and the improvement of symptoms when glucose and galactose are avoided. The diagnosis can be confirmed by genetic testing. Treatment involves a fructose based formula and a continued diet low in foods with glucose and galactose. Many children are able to tolerate more glucose and galactose as they near adulthood, although why this happens is not understood.[1] People with GGM (even during infancy and childhood) are at an increased risk of developing kidney stones or more widespread deposits of calcium within the kidneys. [2]
Last updated: 11/29/2016

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
Percent of people who have these symptoms is not available through HPO
Abdominal distention
Abdominal bloating
Abdominal swelling
Belly bloating
Bloating
[ more ]
0003270
Abnormal oral glucose tolerance 0004924
Autosomal recessive inheritance 0000007
Chronic diarrhea 0002028
Failure to thrive
Faltering weight
Weight faltering
[ more ]
0001508
Glycosuria
Glucose in urine
0003076
Hyperactive bowel sounds
Increased bowel sounds
0030143
Hypertonic dehydration 0001986
Malabsorption
Intestinal malabsorption
0002024
Metabolic acidosis 0001942
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Last updated: 7/1/2020

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease


These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Glucose-galactose malabsorption. This website is maintained by the National Library of Medicine.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Glucose-galactose malabsorption. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.


  1. Berni Canani R, Pezzella V, Amoroso A, Cozzolino T, Di Scala C, and Passariello A. Diagnosing and Treating Intolerance to Carbohydrates in Children. Nutrients. 2016. March 2016; 8(3):157. https://www.ncbi.nlm.gov/pmc/articles/PMC4808885/.
  2. Saadah OI, Alghamdi SA, Sindi HH, Alhunaitti H, Bin-Taleb YY, and Alhussaini BH. Congenital glucose-galactose malabsorption: a descriptive study of clinical characteristics and outcome from Western Saudi Arabia. Arab J Gastroentero. March 2014; 15(1):21-23. https://www.ncbi.nlm.nih.gov/pubmed/24630509.