Galactosemia is a recessive hereditary metabolic disorder in which the enzyme necessary to convert galactose into glucose is missing.
What is Galactosemia?
Hereditary galactosemia is among the most common carbohydrate metabolism disorders and can be a life-threatening illness during the newborn period.
- Galactosemia is a recessive hereditary metabolic disorder in which the enzyme necessary to convert galactose into glucose is missing.
- First described in a variant patient in 1935 by Mason and Turner, galactose-1-phosphate uridyltransferase (GALT) deficiency is the most common enzyme deficiency that causes hypergalactosemia.
- Removing lactose largely eliminates the toxicity associated with newborn disease, but long-term complications routinely occur, as reported by Komrower and Lee in 1970 and then delineated in a 1990 retrospective survey by Waggoner and associates.
Hypergalactosemia is associated with the following 3 enzyme deficiencies.
- Galactokinase converts galactose to galactose-1-phosphate and is not a common deficiency.
- Uridine diphosphate (UDP) galactose-4-epimerase epimerizes UDP galactose to UDP glucose and is also uncommon.
- GALT is responsible for hereditary galactosemia and is the most common deficiency. This enzyme catalyzes the conversion of galactose-1-phosphate and UDP glucose to UDP galactose and glucose-1-phosphate. Individuals with GALT deficiency manifest abnormal galactose tolerance.
Statistics and Incidences
Incidence is approximately 1 case per 40,000-60,000 persons.
- Incidence widely varies (ie, 1 case in 70,000 people in the UK but 1 case in 16,476 people in Ireland.); the disorder is thought to be much less common in Asians.
- Most patients appear to reach adulthood following institution of a galactose-restricted diet.
- Galactosemia occurs in all races; however, galactosemia variants are based on the exact gene defect.
- Galactosemia equally affects males and females.
- Galactosemia is most often diagnosed in infancy by newborn screening because all states include galactosemia as part of their newborn screen.
Untreated infants with severely deficient galactose-1-phosphate uridyltransferase (GALT) activity typically present with the following variable findings:
- Poor growth. Poor growth within the first few weeks of life of the infant.
- Jaundice. There is yellowish discoloration of the infant’s skin because of hyperbilirubinemia.
- Bleeding. Bleeding from coagulopathy is also a symptom of galactosemia.
- Feeding difficulties. Early feeding difficulties with vomiting and diarrhea severe enough to produce dehydration and weight loss and jaundice are primary manifestations.
- Cataracts. Cataracts may occur unless milk is withheld early.
- Liver and spleen damage. Liver and spleen may dysfunction, leading to hepatomegaly and splenomegaly.
Assessment and Diagnostic Findings
Galactosemia can be identified earlier through newborn screening.
- Beutler test. A screening test called Beutler test can be used to test for the disorder.
- Newborn screening. A positive (ie, abnormal) indication on the newborn screen must be followed by a quantitative erythrocyte galactose-1-phosphate uridyltransferase (GALT) analysis by a laboratory that routinely performs biochemical genetic testing and consultation.
- GALT isoelectric-focusing electrophoresis test. A GALT isoelectric-focusing electrophoresis test helps distinguish variant forms such as the Duarte defect.
- GALT genotyping. GALT genotyping may provide a specific molecular diagnosis; the most common GALT allele in Caucasians is the Q188R mutation. The S135L mutation is common in native South Africans and in African Americans.
The mainstay of medical care in the postnatal period is to immediately discontinue ingestion of lactose-containing formula.
- Transfusions. Clotting abnormalities may be cryptic and require fresh frozen plasma treatments.
- Diet. Prescribe a galactose-restricted diet for infants who are galactosemic; a substitution for milk, such as Nutramigen and Pregestimil, can provide galactose-free nutrition for the infants.
Drug therapy currently is not a component of the standard of care for this condition.
Nursing care mainly centers on the intake of the child.
Assessment of a child with galactosemia include:
- Physical examination. Assess the child’s presenting symptoms, especially after ingestion of galactose.
- Nutritional intake. Assess the child’s dietary needs, and the family caregivers understanding of the disorder to establish a strict diet regime.
- Altered nutrition: less than body requirements related to restrictive diet.
- Ineffective breastfeeding related to intolerance to galactose.
- Diarrhea related to ingestion of galactose-containing substance.
Nursing Care Planning and Goals
The major nursing care planning goals for a child with galactosemia are:
- The caregivers will be able to identify the appropriate food for the infant.
- The caregivers will be able to provide galactose-free milk as a substitution for breastmilk.
- The caregivers will be able to understand the disease process and the care of the newborn with galactosemia.
Nursing interventions for a child with galactosemia include:
- Milk substitution. A soy-based formula, meat-based formula, or Nutramigen, or another soy-based formula that contains no galactose should be substituted into the infant’s diet.
- Dietary restrictions. Infants with galactosemia must remain on a restricted diet and maintain low blood galactose levels throughout life.
- Read food labels. Labels on all processed foods must be read carefully for ingredients which are milk products.
- Client education. Ascertain the level of understanding of the family caregivers and provide complete information on the disorder.
Goals are met as evidenced by:
- The caregivers identified the appropriate food for the infant.
- The caregivers provided galactose-free milk as a substitution for breastmilk.
- The caregivers understood the disease process and the care of the newborn with galactosemia.
Documentation guidelines for a child with galactosemia include:
- Individual findings, including factors affecting, interactions, nature of social exchanges, specifics of individual behavior.
- Intake and output.
- Characteristics of stool and vomitus.
- Cultural and religious beliefs, and expectations.
- Plan of care.
- Teaching plan.
- Responses to interventions, teaching, and actions performed.
- Attainment or progress toward the desired outcome.
Practice Quiz: Galactosemia
1. Answer: D. 1.030
- Option D: The normal range of specific gravity of urine is 1.010 to 1.025; a value of 1.030 may be seen with dehydration.
- Options A, B, C: Options A, B, and C are all within the normal range.
2. Katrina is diagnosed with galactosemia. To avoid complications with lack of calcium in the diet, which food should be included in the diet?
A. Whole grains
C. Dark green, leafy vegetables
D. Milk and cheese products
2. Answer: C. Dark green, leafy vegetables.
- Option C: Dark, green leafy vegetables are a rich source of calcium.
- Option A: Whole grains mainly consists of fiber.
- Option B: Some fruits contain calcium but not as abundant as dark green vegetables.
- Option D: Milk and cheese products are not appropriate for a child with galactosemia.
3. The nurse is teaching the mother of a 5 month-old about nutrition for her baby. Which statement by the mother indicates the need for further teaching?
A. “I keep formula in the refrigerator for 24 hours.”
B. “When he wakes at night for a bottle, I feed him.”
C. “I dip his pacifier in honey so he’ll take it.”
D. “I’m going to try feeding my baby some rice cereal.”
3. Answer: C. “I dip his pacifier in honey so he’ll take it.”
- Option C: Honey has been associated with infant botulism and should be avoided. Older children and adults have digestive enzymes that kill the botulism spores.
- Option A: Keeping the formula in the refrigerator would avoid spoiling the milk.
- Option B: Bottle-feeding the infant at night when he wakes up can be done.
- Option D: Rice cereals can be slowly fed to a 5-month old baby.
4. A postpartum nurse is providing instructions to the mother of a newborn infant with hyperbilirubinemia who is being breastfed. The nurse provides which most appropriate instructions to the mother?
A. Switch to bottle feeding the baby for 2 weeks.
B. Stop the breastfeeding and switch to bottle-feeding permanently.
C. Continue to breastfeed every 2-4 hours.
D. Feed the newborn infant less frequently.
4. Answer: C. Continue to breastfeed every 2-4 hours.
- Option C: Breastfeeding should be initiated within 2 hours after birth and every 2-4 hours thereafter.
- Options A, B, D: The other options are not necessary.
5. To help limit the development of hyperbilirubinemia in the neonate, the plan of care should include:
A. Instituting phototherapy for 30 minutes every 6 hours.
B. Monitoring for the passage of meconium each shift.
C. Substituting breastfeeding for formula during the 2nd day after birth.
D. Supplementing breastfeeding with glucose water during the first 24 hours.
5. Answer: B. Monitoring for the passage of meconium each shift.
- Option B: Bilirubin is excreted via the GI tract; if meconium is retained, the bilirubin is reabsorbed.
- Options A, C, D: The other options do not limit the development of hyperbilirubinemia.