Galactosemia is the inability of the body to use (metabolize) the simple sugar galactose, causing the accumulation of galactose 1-phosphate in the body. This causes damage to the liver, central nervous system, and other body systems.
Alternative Names of Galactosemia are: Galactose-1-phosphate uridyl transferase deficiency; Galactokinase deficiency; Galactose-6-phosphate epimerase deficiency.
Complications of Galactosemia
Severe infection with bacteria (E. coli sepsis)
Delayed speech development
Severe mental retardation
Irregular menstrual cycles, decreased function of ovaries, leading to ovarian failure
Tremors and uncontrollable motor functions
Death, if diet is not adhered to
Causes of Galactosemia
Galactosemia is an inherited enzyme disorder (transmitted as an autosomal recessive trait). It occurs in approximately 1 out of every 60,000 births among Caucasians, while the rate is different for other groups.
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 refuse to eat and develop 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.
Signs & Symptoms of Galactosemia
Jaundice (yellowish discoloration of the skin and the whites of the eyes)
Poor feeding (baby refusing to drink milk-containing formula)
Poor weight gain
Diagnosis of Galactosemia
Hepatomegaly (enlarged liver)
Hypoglycemia (low blood sugar)
Aminoaciduria (amino acids are present in the urine and/or blood plasma)
Ascites (fluid collects in the abdomen)
Prenatal diagnosis by direct measurement of the enzyme galactose-1-phosphate uridyl transferaseA
The presence of "reducing substances" in the infant's urine with normal or low blood sugar while the infant is being fed breast milk or a formula containing lactose. A simple test on the urine indicates the presence of a reducing substance, and a specific enzymatic study on the urine can prove the substance to be galactose.
Presence of chemicals, called ketones, in the urine
Measurement of enzyme activity in the red blood cells
Blood culture for bacteria infection (E. coli sepsis)
Treatments of Galactosemia
Once the disease is recognized, treatment consists of strictly avoiding all milk, milk-containing products, and other foods that contain galactose. The infant can be fed with soy formula, meat-base formula, or Nutramigen (a protein hydrolysate formula), or other lactose-free formula.
The condition is lifelong and requires abstinence from milk, milk products, and galactose-containing foods for life. Calcium supplements are recommended.
Parents need to take care and educate the child to avoid not only milk and milk products, but also those foods that contain dry milk products. For this reason, it is essential to read product labels and be an informed consumer.
Prevention of Galactosemia
A personal knowledge of family history is helpful. If there is a family history of galactosemia, genetic counseling will help prospective parents make decisions about pregnancy and prenatal testing. Once the diagnosis of galactosemia is made, genetic counseling is recommended for other members of the family.
Many states have mandatory screening of newborns for galactosemia. Parents may receive a call from a health care provider that says the screening test indicates possible galactosemia. At that time, the parents should promptly stop milk products and have a blood test done for galactosemia through their doctor.
When to seek Medical Advice
If your infant shows a combination of galactosemia symptoms
If you have a family history of galactosemia and are considering having children.