GALK deficiency

GALK Deficiency

GALK deficiency, also known as Galactokinase deficiency, is a rare genetic disorder that affects the body's ability to process the sugar galactose properly. This condition is part of a group of disorders known as galactosemia.

Etiology

GALK deficiency is caused by mutations in the GALK1 gene, which provides instructions for making the enzyme galactokinase. This enzyme is responsible for the first step in the metabolism of galactose, converting it into galactose-1-phosphate. Without functional galactokinase, galactose accumulates in the body, leading to various symptoms.

Symptoms

The primary symptom of GALK deficiency is the development of cataracts in infancy or early childhood. Cataracts are clouding of the lens of the eye, which can lead to vision problems. Other symptoms may include:

• Hepatomegaly
• Jaundice
• Failure to thrive

Diagnosis

Diagnosis of GALK deficiency is typically made through newborn screening programs that test for elevated levels of galactose in the blood. Confirmatory tests include:

• Measurement of galactokinase activity in red blood cells
• Genetic testing for mutations in the GALK1 gene

Treatment

The primary treatment for GALK deficiency is a galactose-restricted diet. This involves avoiding foods that contain lactose, as lactose breaks down into glucose and galactose. Early dietary intervention can prevent the development of cataracts and other complications.

Prognosis

With early diagnosis and proper dietary management, individuals with GALK deficiency can lead normal lives. However, if left untreated, the accumulation of galactose can lead to serious complications, including permanent vision impairment.

Epidemiology

GALK deficiency is a rare disorder, with an estimated prevalence of 1 in 100,000 to 1 in 1,000,000 live births. It is more common in certain populations, such as the Romani people.

Research

Ongoing research is focused on better understanding the genetic mutations that cause GALK deficiency and developing new treatments. Gene therapy and enzyme replacement therapy are potential future treatments under investigation.

See Also

• Galactosemia
• Galactose-1-phosphate uridyltransferase deficiency
• Galactose epimerase deficiency

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NIH genetic and rare disease info

• NIH info on GALK deficiency

GALK deficiency is a rare disease.