| Subject | Contents |
| 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 | 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) and deficiency of galactose kinase or galactose-6-phosphate epimerase. Of these, the galactose-1-phosphate transferase deficiency is the most severe (and more common). People with galactosemia are unable to fully metabolize the simple sugar galactose. Galactose makes up half of the sugar, called lactose, that is found in milk. Lactose is called a disaccharide (di meaning 2 and saccharide meaning sugar) since lactose is made up of two sugars, galactose and glucose, bound together. If an infant with galactosemia is given milk, derivatives of galactose builds up in the infants system causing damage to the liver, brain, kidneys, and eyes. Individuals with galactosemia cannot tolerate any form of milk (human or animal), or 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 infant with galactosemia, will develop intolerance of feeding, jaundice , vomiting , lethargy , irritability , and convulsions . The liver is 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 . |
| Symptoms | Jaundice (yellowish discoloration of the skin and the whites of the eyes) VomitingPoor feeding (baby refusing to drink milk-containing formula) Poor weight gainLethargyIrritabilityConvulsions |
| Signs and tests | Hepatomegaly (enlarged liver) Hypoglycemia (low blood sugar) Aminoaciduria (amino acids are present in the urine) CirrhosisAscites (fluid collects in the abdomen) Mental retardationCataract formation Tests include: Prenatal diagnosis by direct measurement of the enzyme galactose-1-phosphate uridyl transferase . Reducing substances in infants urine with simultaneous normal or low blood sugar while the infant is being fed breast milk or a formula containing lactose. One simple test on the urine with Clinitest indicates the presence of a reducing substance, and a specific enzymatic study on the urine can prove the substance to be galactose. Presence of chemical, called ketones, in urine. Measurement of enzyme activity in erythrocytes (red blood cells). Blood culture for bacteria infection ( E. coli sepsis ). |
| Treatment | Once the disease is recognized, treatment consists of strictly avoiding all milk and milk-containing products. 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 and milk products for life. 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. |
| Support Groups | Parents of Galactosemic Children, Inc. www.galactosemia.org 775-626-5811 |
| Expectations (prognosis) | If diagnosis is made early and milk products are strictly avoided, the prognosis is for a relatively normal life. Despite strict avoidance of galactose, mild intellectual impairment may still develop. |
| Complications | CataractsCirrhosis Severe infection with bacteria ( E. coli sepsis ) Delayed speech development Severe mental retardation Irregular menstrual cycles, decreased function of ovaries, leading to ovarian failure Death, if diet is not adhered to |
| Calling your health care provider | If your infant shows a combination of galactosemia symptoms If you have a family history of galactosemia and are considering having children. |
| Prevention | 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 for galactosemia in newborn's blood. 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. |
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