9337. Genetics. Gilbert syndrome (gene UGT1A1)

Genetic testing to identify a polymorphism in the UGT1A1 gene associated with the development of Gilbert syndrome – an inherited disorder of bilirubin metabolism that manifests as periodic episodes of jaundice and neurological symptoms.

Gilbert's syndrome is a benign hereditary liver disorder characterized by impaired bilirubin conjugation due to reduced activity of the glucuronosyltransferase enzyme (UGT1A1). As a result, levels of unconjugated (indirect) bilirubin increase in the blood, which periodically presents with jaundice, fatigue, irritability, or impaired concentration.

In 90% of cases, Gilbert's syndrome is associated with a mutation in the regulatory region of the UGT1A1 gene, specifically an increase in the number of (TA) repeats in the promoter (most commonly A(TA)7TAA instead of the normal A(TA)6TAA). This leads to a 30-70% reduction in enzyme activity. The test helps confirm the diagnosis, assess the risk of developing clinical manifestations in healthy mutation carriers, and avoid complications of pharmacological therapy.

• Individuals with periodically elevated bilirubin levels in the absence of other signs of liver disease.
• When Gilbert syndrome is suspected, particularly with clinical jaundice occurring during childhood or adolescence.
• Individuals planning to take potentially hepatotoxic medications, such as irinotecan or protease inhibitors.
• People with a family history of Gilbert syndrome.
• For differential diagnosis with other causes of hyperbilirubinemia, including hemolytic anemia, hepatitis, and Crigler–Najjar syndrome.

• Venous blood

In order to exclude factors that may affect the test results, we recommend to follow the preparation rules: