Galactose-1-phosphate uridyl transferase deficiency

=Galactose-1-phosphate uridyl transferase deficiency = Galactose-1-phosphate uridyl transferase deficiency, also known as Classic Galactosemia, is a rare genetic metabolic disorder that affects the body's ability to process the sugar galactose properly. This condition is caused by a deficiency in the enzyme galactose-1-phosphate uridyl transferase (GALT), which is crucial for the proper metabolism of galactose.

Pathophysiology

Galactose is a simple sugar found in milk and dairy products, as well as in some other foods. In individuals with GALT deficiency, the enzyme responsible for converting galactose-1-phosphate into UDP-galactose is deficient or absent. This leads to the accumulation of galactose-1-phosphate and other toxic substances in the body, causing damage to various organs and tissues.

Genetics

Galactose-1-phosphate uridyl transferase deficiency is inherited in an autosomal recessive pattern. This means that an individual must inherit two copies of the defective gene, one from each parent, to be affected by the disorder. The gene responsible for this condition is located on chromosome 9.

Symptoms

Symptoms of classic galactosemia typically appear shortly after birth and can include:

• Poor feeding
• Vomiting
• Jaundice
• Liver dysfunction
• Cataracts
• Developmental delay

If left untreated, the condition can lead to serious complications such as liver failure, sepsis, and intellectual disability.

Diagnosis

Diagnosis of galactose-1-phosphate uridyl transferase deficiency is usually made through newborn screening programs, which test for elevated levels of galactose or galactose-1-phosphate in the blood. Confirmatory testing involves measuring the activity of the GALT enzyme in red blood cells.

Treatment

The primary treatment for classic galactosemia is a strict galactose-free diet, which involves avoiding all milk and dairy products, as well as other foods containing galactose. Early dietary intervention can prevent many of the acute symptoms and complications of the disorder.

Prognosis

With early diagnosis and dietary management, individuals with galactose-1-phosphate uridyl transferase deficiency can lead relatively normal lives. However, some long-term complications, such as speech and learning difficulties, may still occur despite dietary treatment.

See Also

• Galactosemia
• Metabolic disorders
• Newborn screening

,

 Classic Galactosemia and Clinical Variant Galactosemia, 
 GeneReviews, 
 2020,

,

 The Metabolic and Molecular Bases of Inherited Disease, 
  
 McGraw-Hill, 
 2001,

NIH genetic and rare disease info

• NIH info on Galactose-1-phosphate uridyl transferase deficiency

Galactose-1-phosphate uridyl transferase deficiency is a rare disease.