From the Guidelines
Gilbert's syndrome is a benign, mild genetic liver disorder characterized by impaired bilirubin processing, leading to occasional mild jaundice, and requires no treatment. This condition affects approximately 3-7% of the population and is typically harmless, with no impact on liver function or life expectancy 1. The syndrome occurs due to a mutation in the UGT1A1 gene, reducing the liver's ability to convert bilirubin into a water-soluble form for excretion. Key characteristics of Gilbert's syndrome include:
- Elevated unconjugated bilirubin levels, which may rise during times of stress, fasting, illness, or physical exertion
- Occasional mild jaundice (yellowing of the skin and eyes)
- No liver damage or impact on liver function
- Typically discovered during routine blood tests showing slightly elevated bilirubin
- No necessary medications, dietary restrictions, or lifestyle changes, although avoiding prolonged fasting may help prevent episodes
- Lifelong condition with normal life expectancy. According to a recent study, even fasting, such as during Ramadan, may not significantly exacerbate the condition in the long term 1.
From the Research
Definition of Gilbert's Syndrome
- Gilbert's syndrome (GS) is characterized by the existence of chronic mild unconjugated hyperbilirubinaemia 2
- It is a common autosomal dominant hereditary condition with incomplete penetrance and is characterized by intermittent unconjugated hyperbilirubinemia in the absence of hepatocellular disease or hemolysis 3
- GS is the most common inherited disorder of bilirubin metabolism 4
Key Features
- Reduced uridine diphosphate-glucuronyl transferase activity to 30% of the normal, resulting in indirect hyperbilirubinemia 3
- Intermittent mild jaundice in adolescence is a typical form of hyperbilirubinemia 3
- GS may potentiate severe hyperbilirubinemia and/or cholelithiasis when combined with other prevailing conditions such as breast feeding, G-6-PD deficiency, thalassemia, spherocytosis, or cystic fibrosis 3
- GS may also reduce plasma oxidation and affect drug metabolism 3
Diagnosis
- Diagnosis of GS is typically one of exclusion, but molecular genetic tests can be performed when there is a diagnostic problem 3
- The most common genotype of GS is the homozygous polymorphism A(TA)7TAA in the promoter of the gene for UDP-glucuronosyltransferase 1A1 (UGT1A1) 3
- Rifampin test can be used as a diagnostic test for GS, with a significant increase in mean unconjugated bilirubin levels in patients with GS 2, 4, 5
- Overnight rifampin test may be useful for the diagnosis of GS if cut-off levels for serum total and unconjugated bilirubin level of more than 2.4 and 1.3 mg/dL are used 4