Summary about Disease
Galactokinase deficiency (GALK deficiency) is a rare, inherited metabolic disorder characterized by a deficiency of the enzyme galactokinase. This enzyme is necessary for the proper metabolism of galactose, a sugar found in milk and other foods. The deficiency leads to an accumulation of galactose and galactitol in the blood and tissues. The primary clinical manifestation is the development of cataracts, usually in infancy.
Symptoms
Cataracts: The most common and often the only symptom. These cataracts typically develop early in infancy.
(Rarely) Pseudotumor cerebri: Increased pressure inside the skull.
Developmental Delay (rare): In some cases, if the condition is untreated, mild developmental delays may occur.
Liver Dysfunction (rare): Can happen with significant galactose buildup.
Causes
Galactokinase deficiency is caused by mutations in the GALK1 gene. This gene provides instructions for making the galactokinase enzyme. The condition is inherited in an autosomal recessive manner, meaning an affected individual must inherit two copies of the mutated gene (one from each parent) to develop the disorder. If an individual inherits only one mutated copy, they are considered a carrier and usually do not show symptoms.
Medicine Used
4. Medicine used There is no specific medicine used to treat galactokinase deficiency. The primary treatment involves dietary restriction of galactose.
Galactose-restricted diet: The main approach is to avoid galactose-containing foods such as:
Milk and dairy products.
Some fruits and vegetables containing galactose.
Foods containing milk solids or whey.
Is Communicable
No, galactokinase deficiency is not communicable. It is a genetic disorder and cannot be spread from person to person.
Precautions
Dietary Management: Strict adherence to a galactose-restricted diet is crucial. Consult a registered dietitian with experience in metabolic disorders.
Early Detection: Newborn screening programs can identify the condition early.
Genetic Counseling: Families with a history of galactokinase deficiency should seek genetic counseling to understand the risk of recurrence.
Regular Eye Exams: Monitor for the development or progression of cataracts.
How long does an outbreak last?
Galactokinase deficiency is not an infectious disease and does not involve outbreaks. It is a chronic, lifelong condition that requires ongoing management. Cataracts can develop rapidly in infancy if dietary restrictions are not implemented.
How is it diagnosed?
Newborn Screening: Many states include galactokinase deficiency in their newborn screening programs, which involves testing a small blood sample from the baby's heel.
Blood Galactose Levels: Elevated levels of galactose in the blood may indicate the condition.
Urine Galactitol Levels: Elevated levels of galactitol in the urine can also be indicative of GALK deficiency.
Enzyme Assay: Measuring galactokinase enzyme activity in red blood cells.
Genetic Testing: Analyzing the GALK1 gene for mutations.
Eye Exam: An ophthalmological exam will identify cataracts.
Timeline of Symptoms
Birth/Early Infancy: Elevated galactose levels are detectable through newborn screening.
Within first few months of life: Cataracts typically begin to develop if galactose intake is not restricted. The speed varies.
Later in Infancy/Childhood (if untreated): In rare cases, developmental delays may become apparent.
Important Considerations
Dietary Adherence: Maintaining a strict galactose-free diet throughout life is crucial to preventing long-term complications.
Nutritional Adequacy: Ensuring adequate nutrition while restricting galactose is important, especially during periods of growth.
Lifelong Monitoring: Regular monitoring of galactose levels and ophthalmological exams are necessary to assess the effectiveness of treatment and identify any potential complications.
Support Groups: Connecting with other families affected by galactokinase deficiency can provide valuable support and information.
Education: Educating caregivers, school personnel, and other relevant individuals about the condition and dietary requirements is important for ensuring appropriate management.