Summary about Disease
Galactose-1-phosphate uridyltransferase (GALT) deficiency, also known as classic galactosemia, is an inherited metabolic disorder that prevents the body from properly processing galactose, a simple sugar found in milk, dairy products, and some fruits and vegetables. This deficiency is caused by mutations in the GALT gene, leading to a buildup of galactose and galactose-1-phosphate in the body, which can damage the liver, brain, kidneys, and eyes. Early diagnosis and dietary management are crucial to prevent severe complications.
Symptoms
Symptoms typically appear within the first few days or weeks of life if galactose is consumed. These can include:
Feeding difficulties
Vomiting
Diarrhea
Lethargy
Jaundice (yellowing of the skin and eyes)
Failure to thrive (poor weight gain and growth)
Hepatomegaly (enlarged liver)
Cataracts
Increased susceptibility to serious bacterial infections (sepsis)
Developmental delays, intellectual disability, and speech problems can occur if left untreated.
Causes
Classic galactosemia is caused by mutations in the GALT gene, which provides instructions for making the galactose-1-phosphate uridyltransferase enzyme. This enzyme is essential for converting galactose-1-phosphate into glucose-1-phosphate, a step in galactose metabolism. Mutations in the *GALT* gene reduce or eliminate the activity of this enzyme, leading to the accumulation of galactose and galactose-1-phosphate in tissues and organs. It is inherited in an autosomal recessive manner, meaning that both parents must carry a copy of the mutated gene for a child to be affected.
Medicine Used
4. Medicine used There is no specific medicine to "cure" galactosemia. The primary treatment is dietary restriction. However, antibiotics are crucial for treating bacterial infections (sepsis) that affected infants may develop, and these are used as necessary on a case by case basis.
Is Communicable
No, galactosemia is not communicable. It is a genetic disorder caused by inherited gene mutations and cannot be spread from person to person.
Precautions
The primary precaution is strict adherence to a galactose-free diet throughout life. This includes avoiding:
Milk and dairy products
Foods containing milk solids, whey, or casein
Some fruits and vegetables with high galactose content (these may need to be limited)
Certain medications that may contain lactose as a filler
Careful label reading is essential to identify hidden sources of galactose.
Infants need to be fed with special galactose-free formula.
Lifelong monitoring by a metabolic specialist is recommended.
How long does an outbreak last?
Galactosemia is not an "outbreak" situation; it is a chronic, lifelong condition. Symptoms will persist as long as galactose is consumed. With proper dietary management, acute symptoms can be avoided, but the underlying genetic condition remains.
How is it diagnosed?
Diagnosis typically involves:
Newborn screening: A blood test performed shortly after birth to detect elevated levels of galactose.
Enzyme assay: A blood test to measure the activity of the GALT enzyme. Reduced or absent GALT activity confirms the diagnosis.
Genetic testing: Analyzing the GALT gene for mutations.
Urine test: Measuring the amount of galactitol present in the urine.
Timeline of Symptoms
First few days/weeks of life: Symptoms typically appear if the infant is fed milk or other galactose-containing substances.
Without treatment: Symptoms worsen rapidly, leading to liver damage, cataracts, sepsis, and neurological damage.
With treatment (galactose-free diet): Acute symptoms resolve, but long-term complications such as speech problems, motor skill issues, and ovarian dysfunction (in females) can still occur despite dietary control. These complications are related to how early treatment was started, and how well galactose consumption is controlled.
Important Considerations
Early diagnosis is critical: Newborn screening is essential for preventing severe complications.
Lifelong dietary adherence: A galactose-free diet is the cornerstone of treatment and requires careful planning and monitoring.
Nutritional counseling: Consultation with a registered dietitian is vital for ensuring adequate nutrition while following a restricted diet.
Long-term monitoring: Regular follow-up with a metabolic specialist is necessary to assess growth, development, and potential complications.
Genetic counseling: Families affected by galactosemia should receive genetic counseling to understand the inheritance pattern and recurrence risk.
Support groups: Connecting with other families affected by galactosemia can provide valuable emotional support and practical advice.