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What is Gilbert’s Syndrome?
Gilberts Syndrome (also known as Gilberts Disease) is a mild inherited disorder that causes mild Jaundice due to slightly raised levels of unconjugated bilirubin. The plasma unconjugated bilirubin concentrations in Gilberts Syndrome are usually within the range of 20 micro moles per liter to 40 micromoles per liter. The bilirubin level rarely exceeds 80 micromoles/L. The level of unconjugated bilirubin fluctuates and may rise in dehydration, menstruation and fasting.
Gilberts Syndrome is a form of unconjugated bilirubinemia that is not caused by hemolysis (break down of red blood cells) but as a result of inheritance (inheritance is by autosomal dominant pattern). Gilberts Syndrome is harmless but should be differentiated from other liver diseases that require medical attention such as hemolysis that causes hemolytic jaundice and also to prevent unnecessary investigations that may cost the patient money and anxiety.
In Gilberts Syndrome, there is mutation in hepatic Uridine DiphosphoGlucoronyltrasnferase (UGT) gene because UGT enzyme activity is decreased by 30% of normal. It is the most common familial hyperbilirubinemia and affects about 6% of the total population worldwide. It is grouped as one of the causes of Congenital Non-Hemolytic Hyperbiliruniemia.
Gilberts Syndrome epidemiology
Gilberts Syndrome is a relatively common familial condition; it may occur at any age but mostly occurs after the second decade of life.
Gilberts Syndrome Trigger Factors
- Stress
- Intercurrent illness
- Strenuous exercise
- Fasting
- Very low calorie diet
- Alcohol intake
- Vomiting
- Menstruation
- Dehydration
Gilberts Syndrome Symptoms
- Mostly asymptomatic: may not show any sign or symptoms unless there is a trigger such as stress ( see triggers above)
- Mild Jaundice (yellowish change of eyes and skin)
- Other symptoms may include fatigue
Gilberts Syndrome/Disease Diagnosis
Diagnosis of Gilberts Syndrome is made exclusion of possible causes of hemolysis in the patient and other liver diseases. Prolonged fasting (about 48hrs with calories restricted to 300kcal/day) may result in an increase of plasma bilirubin concentration by 90%, with unconjugated bilirubin rising by more than 100% in Gilberts Syndrome.
Gilberts Syndrome becomes evident when plasma bilirubin concentrations fail to return to normal values following acute hepatitis infection or during mild illnesses. This may cause misdiagnosis as being hepatitis.
Liver function tests are normal and no form of liver function derangement.
Gilberts Syndrome Treatment
No treatment is required in Gilberts Syndrome as the disease is mild. The patient needs reassurance because of the anxiety the patient may experience seeing his/her eyes yellow and may think it is a serious liver disease. If Jaundice is significant, phenobarbitone can be used.
Gilberts Syndrome Complications
- Gilberts Syndrome is linked with increased risk of gallstones
- Few people having Gilberts Syndrome may have deficiency of the enzyme responsible for Paracetamol (acetaminophen) metabolism and this causes increased risk of toxicity to this drug. This is not just to acetaminophen alone; any enzyme deficiency can cause toxicity of the drug that is supposed to have been detoxified by the enzyme concerned such as toxicity of Irinotecan(a drug used for treatment of colon cancer) that can cause severe diarrhea and lower the neutrophil count due to deficiency of the enzyme UGT in patients with Gilberts syndrome.
Drugs to avoid in Gilberts Syndrome
- Irinotecan (for treating colon cancer)
- Gemfibrozil to reduce cholesterol
- Statins cholesterol lowering agent
- Indinavir
- Atazanavir
- Paracetamol
- Nilotinib (use for treating some hematological malignancies)
Gilberts Syndrome Differential Diagnosis
- Crigler-Najjar Syndrome (Type I and II)
- Physiological jaundice of the newborn
- Hemolysis
- Dubin-Johnson Syndrome
Gilberts Syndrome is mild and some doctors prefer to call it a syndrome rather than Gilberts Disease while others use the two interchangeably.