Gilbert's disease/syndrome

Introduction

A common, benign hereditary form of hyperbilirubinemia & jaundice.

Etiology

• UDP-glucuronyltransferase 1 deficiency

Epidemiology

• 3-7% of US population; up to 5%

Pathology

• inadequate conjugation of bilirubin leads to an accumulation of unconjugated bilirubin.

Genetics

• autosomal dominant
• associated with defects in UGT1A1,UGT1A4 genes

Clinical manifestations

• patients are generally asymptomatic
• jaundice may occur during times of stress such as starvation, illness, or alcohol consumption
• patients may present as young adults with vague nonspecific complaints

Laboratory

• unconjugated bilirubin serum levels range from 1-6 mg/dL, generally < 4 mg/dL
• diagnosis is made by exclusion of hemolysis & intrinsic liver disease as the etiology of unconjugated hyperbilirubinemia
  • reticulocyte count is normal (up to 1.5%)
  • direct antiglobulin test unnecessary if reticulocyte count & peripheral blood smeal are normal
  • serum ALT & serum AST are normal
• nicotinic acid-induced hyperbilirubinemia
• UGT1A1 gene mutation

Management

• phenobarbital induces defective enzyme & will decrease plasma unconjugated bilirubin, but treatment is generally unnecessary

More general terms

• bilirubin metabolism, inborn error

Database

• OMIM: https://mirror.omim.org/entry/143500
• OMIM: https://mirror.omim.org/entry/100675