Glucose-galactose malabsorption

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 dehydration, acidosis, 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.

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. 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.