Galactosemia is a treatable inherited disease that reduces the body's ability to metabolize galactose, a simple sugar found in milk. The classic form of galactosemia can be fatal without prompt treatment and careful management. Because milk is a staple of an infant's diet, diagnosis and treatment within the first week of life is critical to avoiding mental retardation and life-threatening complications.
Classic galactosemia, the most severe form of the disease, is caused by a deficiency in an enzyme called galactose-1-phosphate uridyltransferase. People with classic galactosemia have less than 5% of the normal activity in this enzyme. After only a few days of drinking milk, including breast milk, an infant with classic galactosemia will show symptoms including loss of appetite, jaundice, vomiting, lethargy, and convulsions. Without immediate and vigilant lifelong treatment, children with the condition will experience life-threatening complications such as severe infections, cirrhosis of the liver, and mental retardation. Even with treatment, children can still develop cataracts, speech problems, stunted growth and motor function, and learning disabilities, and most females will eventually develop menstrual irregularities and go through premature menopause.
Duarte galactosemia is a much milder form of the disease in which a person has 25 to 50% of the normal amount of galactose-1-phosphate uridyltransferase. People with Duarte galactosemia generally do not suffer any of the symptoms of classic galactosemia.
Please note that galactosemia is not the same as lactose intolerance, a more common and less serious condition.
Classic galactosemia affects approximately 1 in 30,000 newborns. It is thought that 6% of the U.S. population (6 in 100) is a carrier of Duarte galactosemia.
People with classic galactosemia must monitor their galactose-1-phosphate levels with regular blood tests follow a lifelong diet free of milk, milk products, or other foods containing lactose. Infants should be fed with galactose-free formulas such as soy formula or Nutramigen, a hypoallergenic formula with no galactose, lactose, or soy. As children learn to feed themselves, parents must teach them how to read product labels so they can avoid any food containing milk, dry milk, milk products, and other galactose-containing foods. Often they require calcium supplements to avoid calcium deficiency.
There is debate on whether people with Duarte galactosemia need to adhere to a galactose-free diet. Some medical professionals recommend modifying an affected person's diet while others do not. The decision whether or not to treat a person with Duarte galactosemia may depend upon his or her level of enzyme activity.
People with galactosemia should work with a nutritionist to determine the best course of treatment.
Most people who are diagnosed early with classic galactosemia and carefully follow a galactose-free diet can have a normal lifespan. They are still at risk, however, for cataracts, speech defects, poor growth, poor intellectual function, neurologic deficits and ovarian failure (in women). If the treatment of classic galactosemia is not prompt and consistent, life-threatening complications and irreversible mental retardation can result.
Duarte galactosemia has not been associated with any long-term health problems.
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