Galactosemia

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Galactosemia

Galactosemia

Definition:

Galactosemia is the inability of the body to use (metabolize) the simple sugar galactose (causing the accumulation of galactose 1-phosphate), which then reaches high levels in the body, causing damage to the liver, central nervous system, and various other body systems.

Alternative Names:
Galactose-1-phosphate uridyl transferase deficiency; Galactokinase deficiency; Galactose-6-phosphate epimerase deficiency
Causes, incidence, and risk factors:

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Galactosemia is an inherited disorder (transmitted as an autosomal recessive trait). It occurs at a rate of approximately 1 out of 60,000 births. There are 3 forms of the disease: galactose-1 phosphate uridyl transferase deficiency (classic galactosemia, the most common and most severe form), deficiency of galactose kinase, and deficiency of galactose-6-phosphate epimerase.

People with galactosemia are unable to fully break down the simple sugar galactose. Galactose makes up half of lactose, the sugar found in milk. Lactose is called a disaccharide (di meaning 2 and saccharide meaning sugar) because it is made up of two sugars, galactose and glucose, bound together.

If an infant with galactosemia is given milk, derivatives of galactose build up in the infant's system, causing damage to the liver, brain, kidneys, and eyes. Individuals with galactosemia cannot tolerate any form of milk (human or animal) and must carefully watch intake of other galactose-containing foods. Exposure to milk products may result in liver damage, mental retardation, cataract formation, and kidney failure.

After drinking milk for a few days, a newborn with galactosemia will develop intolerance of feeding, jaundice, vomiting, lethargy, irritability, and convulsions. The liver will be enlarged and the blood sugar may be low. Continued feeding of milk products to the infant leads to cirrhosis of the liver, cataract formation in the eye (which may result in partial blindness), and mental retardation.