Understanding Gilbert’s Syndrome for PLAB 2

Ann Augustin
7 hours ago
2 min read

What is Gilbert's syndrome?

Gilbert’s syndrome is a common, harmless inherited condition where the liver processes bilirubin more slowly than usual due to reduced activity of the UGT1A1 enzyme.

This can cause a mild build-up of unconjugated bilirubin, leading to intermittent yellowing of the eyes or skin.

How to Explain It to a Patient

“There is an important enzyme in the liver that helps clear waste products from the blood. In your case, this enzyme works a little slower than usual, causing a mild build-up of bilirubin, which can occasionally cause yellowing of the eyes or skin.”

Reassurance

Harmless condition
Does not damage the liver
Usually does not require treatment

Common Triggers

Symptoms may worsen during:

Stress
Illness
Fasting
Dehydration
Lack of sleep

Typical Investigation Findings

Hallmark:

Isolated unconjugated hyperbilirubinemia

Test	Finding
Total bilirubin	Mildly raised
Unconjugated bilirubin	Raised
ALT/AST/ALP	Normal

Important Investigations

Exclude Hemolysis

CBC
Reticulocyte count
LDH
Haptoglobin

Exclude Liver Disease

Only if clinically indicated.

Genetic testing is rarely required.

Differential Diagnoses of Unconjugated Hyperbilirubinemia

Hemolysis
Neonatal jaundice
Crigler–Najjar syndrome
Drug-related impaired bilirubin uptake

Gilbert’s vs Crigler–Najjar

Gilbert’s	Crigler–Najjar
Mild & benign	Severe & dangerous
Adolescents/adults	Neonates
Mild bilirubin rise	Very high bilirubin
No treatment needed	May require transplant

Management

No specific treatment required.

Advice:

Eat regular meals
Stay hydrated
Avoid prolonged fasting
Rest adequately

Important Associations

Mild intermittent jaundice
Increased sensitivity to some drugs (e.g. irinotecan, atazanavir)
Rare slight increase in pigment gallstones

Follow-Up in the UK

Routine follow-up is usually not required once diagnosis is confirmed.

Advise review if:

Jaundice becomes persistent
Symptoms worsen
Dark urine, pale stools, or abdominal pain develop

Safety Netting

“Please seek medical attention if you develop worsening jaundice, severe abdominal pain, persistent vomiting, dark urine, or pale stools.”