Galactosemia: Managing This Rare Disorder from Early Diagnosis to Treatment

What is galactosemia?

Galactosemia is a genetic disorder that affects the body's ability to metabolize galactose, a simple sugar present in lactose, the sugar found in milk and dairy products. Individuals with galactosemia lack one of these enzymes which is required for converting galactose into glucose and other usable molecules for energy.

When galactose is not properly metabolized, its byproducts accumulates in the blood, which can cause potential health complications if left untreated. Early detection through newborn screening and a prompt galactosemia treatment are crucial to prevent severe complications and support normal growth and development.

How does this condition affect our child's body?

Galactosemia causes a significant impact on various bodily systems, especially in infants. The accumulation of galactose and its byproducts can lead to several severe health issues.

Digestive System

Infants with galactosemia often experience:

• Poor feeding
• Vomiting
• Diarrhea
• Failure to gain weight and grow as expected

These symptoms occur because the body cannot process the galactose present in breast milk or lactose-containing formulas.

Liver and Kidneys

The buildup of galactose and its metabolites can cause:

• Liver damage
• Jaundice (yellowing of the skin and eyes)
• Potential kidney problems
• Liver enlargement and abnormal liver function are common findings[2][3][5]

Eyes

Cataracts can develop in the lens of the eye due to the toxic effects of galactose.

Infections

Infants have a higher risk of serious bacterial infections, such as sepsis, due to compromised immune function associated with galactosemia.

Developmental Issues

If left untreated, galactosemia can result in:

• Delayed development
• Intellectual disabilities
• Speech difficulties
• Other neurological problems

Even with treatment, some children may experience cognitive and speech impairments. Early diagnosis through newborn screening tests and strict dietary management are essential to mitigate these complications and support the child's normal growth and development.

How does galactosemia affect adults?

Although rare, some adults may have undiagnosed galactosemia or a milder form of the disorder. They may experience long-term health issues such as:

• Females may have premature ovarian insufficiency, leading to infertility and other reproductive issues. Males generally do not face significant reproductive problems.
• Adults may have weaker bones and require calcium supplementation to maintain bone health.
• Some individuals may have mild cognitive impairment, speech difficulties, or other neurological issues persisting into adulthood.

Adults with galactosemia must adhere to a strict galactose-free diet throughout their lives to prevent the accumulation of toxic substances in their bodies. Regular monitoring by healthcare professionals is crucial to manage ongoing health challenges and ensure the best possible quality of life.

Who does galactosemia affect?

Galactosemia is an autosomal recessive disorder, meaning an individual must inherit one copy of the faulty gene from each parent to develop the condition. While parents who are carriers of the mutated gene may not show any symptoms, they have a 25% chance of having a child with galactosemia in each pregnancy.

How common is this condition?

Galactosemia is a rare disorder, with classic galactosemia (the most severe galactosemia type) occurring in approximately 1 in 30,000 to 60,000 newborns. Other galactosemia types, such as galactokinase deficiency and galactose epimerase deficiency, are even rarer, affecting fewer than 1 in 100,000 newborns.

What are the symptoms of galactosemia?

Galactosemia symptoms typically appear within the first few days to weeks of life, as the newborn consumes milk or formula containing lactose. These symptoms may include:

• Poor feeding and vomiting
• Diarrhea and dehydration
• Failure to thrive (poor growth and weight gain)
• Jaundice (yellowing of skin and eyes)
• Lethargy and irritability
• Cataracts in the eyes
• Liver and kidney problems
• Sepsis (blood infection)

If you notice any of these symptoms in your newborn, it's crucial to seek medical attention immediately for prompt diagnosis and treatment.

What causes galactosemia?

Galactosemia causes lie in the mutations in the genes responsible for producing enzymes that break down galactose. These include:

• Mutations in the GALT gene lead to deficiencies in the galactose-1-phosphate uridyltransferase enzyme
• Mutations in the GALK1 gene result in deficiencies in the galactokinase enzyme
• Mutations in the GALE gene cause deficiencies in the galactose-6-phosphate epimerase enzyme

These enzymes are crucial for converting galactose into glucose and other usable forms. Mutations in the genes encoding these enzymes lead to a deficiency or complete absence of the respective enzyme, resulting in the accumulation of galactose and its byproducts in the body.

What are the different types of galactosemia?

Galactosemia is a rare metabolic disorder caused by the inability to process galactose, a sugar found in milk and other foods. There are three main galactosemia types, each caused by different enzymatic deficiencies:

Classic Galactosemia (Type I)

This is the most common and severe form of the condition. It is caused by mutations in the GALT gene, which lead to a nearly complete deficiency of the galactose-1-phosphate uridyltransferase (GALT) enzyme. Without treatment, the accumulation of galactose-1-phosphate can result in life-threatening complications, such as liver failure, sepsis, and developmental delays. Infants with classic galactosemia require immediate intervention with a galactose-free diet to prevent severe outcomes.

Galactokinase Deficiency (Type II)

Type II galactosemia is caused by mutations in the GALK1 gene, leading to a deficiency of the galactokinase enzyme. It is generally less severe than classic galactosemia. The primary symptom is the development of cataracts during infancy due to the accumulation of galactitol in the lens of the eye. Treatment involves a galactose-restricted diet to prevent cataract formation and other complications.

Galactose Epimerase Deficiency (Type III)

This rare and mild form is caused by mutations in the GALE gene, resulting in a deficiency of the galactose-6-phosphate epimerase enzyme. Symptoms can vary and may include delayed growth, developmental delays, liver dysfunction, and cataracts. While some individuals with this condition do not require treatment, others may benefit from a galactose-restricted diet based on symptom severity.

Newborn screening programmes can detect classic galactosemia and galactokinase deficiency early, allowing timely diagnosis and intervention. Genetic testing is essential for identifying the specific type of galactosemia and guiding individualised galactosemia treatment plans.

How is galactosemia diagnosed?

Early diagnosis is crucial for preventing the harmful effects of galactosemia. In many countries, galactosemia is part of the routine newborn screening programme. Here's how the diagnostic process typically works:

• Newborn Screening: A blood sample is taken from the baby's heel within a few days of birth and tested for elevated galactose levels.
• Confirmatory Tests: If the screening test is positive, further blood and urine tests are done to measure enzyme activity and galactose levels. Genetic testing may also be performed to identify the specific mutation.
• Family Screening: Since galactosemia is inherited, family members, particularly siblings, may also be tested.

It's important to note that a positive newborn screen doesn't always mean the baby has galactosemia. False positives can occur, which is why confirmatory testing is essential.

How do you treat galactosemia?

The primary method of galactosemia treatment is removing all sources of galactose from the diet for life. For infants, this means switching from breast milk or regular formula to a galactose-free formula. As children grow, they must avoid milk and dairy products, as well as certain fruits, vegetables, and processed foods that may contain galactose.

In addition to the galactose-restricted diet, people with galactosemia may need regular check-ups, calcium and vitamin D supplements, speech therapy and educational support, and hormone replacement therapy for girls with ovarian insufficiency.

What treatment will our child require for long-term side effects of galactosemia?

Even with a strict diet, some children with galactosemia may still experience long-term complications, such as:

• Speech and language delays
• Learning disabilities or intellectual impairments
• Motor skill delays
• Ovarian failure in girls
• Cataracts

Regular follow-ups with a multidisciplinary healthcare team, including a metabolic specialist, paediatrician, speech therapist, and psychologist, can help monitor and address these issues.

Can galactosemia be prevented?

Since galactosemia is a genetic disorder, it cannot be prevented. However, genetic counselling can be beneficial for families with a history of galactosemia. Prenatal testing is available to determine if a foetus is affected. Early intervention and support services can significantly improve outcomes.

What is the life expectancy of someone with galactosemia?

With early diagnosis and strict adherence to a galactose-free diet, individuals with galactosemia can lead long and healthy lives. However, life expectancy may be affected by the severity of the condition and the presence of long-term complications. Regular medical care and monitoring are essential.

How do adults living with galactosemia take care of themselves?

Adhering to a galactose-restricted diet remains the cornerstone of galactosemia management in adulthood. This requires careful label reading and meal planning to avoid hidden sources of galactose.

Adults with galactosemia should:

• Have regular check-ups with a metabolic specialist and primary care physician
• Monitor bone health with bone density scans and take calcium and vitamin D supplements as needed
• Seek support for any learning, speech, or motor skill difficulties
• Have regular eye exams to check for cataracts
• For women, discuss fertility and reproductive health with a gynaecologist

Connecting with other adults living with galactosemia through support groups can provide valuable insights and emotional support.

Conclusion

Managing galactosemia requires a collaborative effort between healthcare providers, parents, and the affected individual. If you suspect your child may have galactosemia or have concerns about their health, don't hesitate to consult with your healthcare provider.

At Metropolis Healthcare, we understand the importance of accurate and timely diagnosis in managing rare disorders like galactosemia. Our advance diagnostic laboratories and experienced pathologists are committed to providing reliable results to help you make informed decisions about your child's health. With our convenient at-home sample collection services and user-friendly online reporting system, you can prioritize your family's well-being with ease.