Overview

Gilbert's (zheel-BAYRS) syndrome is a common, harmless liver condition in which the liver doesn't properly process bilirubin. Bilirubin is produced by the breakdown of red blood cells.

If you have Gilbert's syndrome — also known as constitutional hepatic dysfunction and familial nonhemolytic jaundice — you're born with the condition as a result of an inherited gene mutation. You might not know you have Gilbert's syndrome until it's discovered by accident, such as when a blood test shows elevated bilirubin levels.

Gilbert's syndrome requires no treatment.

Symptoms

The most frequent sign of Gilbert's syndrome is an occasional yellowish tinge of the skin and the whites of the eyes as a result of the slightly elevated levels of bilirubin in the blood. In people with Gilbert's syndrome, bilirubin levels may increase and jaundice may become apparent because of:

  • Illness, such as a cold or the flu
  • Fasting or eating a very low-calorie diet
  • Dehydration
  • Menstruation
  • Stress
  • Strenuous exercise
  • Lack of sleep

When to see a doctor

Make an appointment with your doctor if you have jaundice, which has many possible causes.

Causes

An abnormal gene you inherit from your parents causes Gilbert's syndrome. The gene normally controls an enzyme that helps break down bilirubin in your liver. When you have an ineffective gene, your blood contains excess amounts of bilirubin because your body doesn't produce enough of the enzyme.

How the body normally processes bilirubin

Bilirubin is a yellowish pigment made when your body breaks down old red blood cells. Bilirubin travels through your bloodstream to the liver, where the enzyme breaks down the pigment and removes it from the bloodstream.

The bilirubin passes from the liver into the intestines with bile. It's then excreted in stool. A small amount of bilirubin remains in the blood.

How the abnormal gene is passed through families

The abnormal gene that causes Gilbert's syndrome is common. Many people carry one copy of this gene. In most cases, two abnormal copies are needed to cause Gilbert's syndrome.

Risk factors

Although it's present from birth, Gilbert's syndrome usually isn't noticed until puberty or later, since bilirubin production increases during puberty. You have an increased risk of Gilbert's syndrome if:

  • Both your parents carry the abnormal gene that causes the disorder
  • You're male

Complications

The low level of the bilirubin-processing enzyme that causes Gilbert's syndrome may also increase the side effects of certain medications, since this enzyme plays a role in helping clear these medications from your body.

These medications include:

  • Irinotecan (Camptosar), a cancer chemotherapy drug
  • Some protease inhibitors used to treat HIV

If you have Gilbert's syndrome, talk to your doctor before taking new medications. Also, having any other condition that impairs the destruction of red blood cells may increase your risk of developing gallstones.

Aug. 23, 2018
References
  1. Chowdhury JR, et al. Gilbert's syndrome and unconjugated hyperbilirubinemia due to bilirubin overproduction. https://www.uptodate.com/contents/search. Accessed Aug. 14, 2018.
  2. National Library of Medicine. Gilbert syndrome. Genetics Home Reference. https://ghr.nlm.nih.gov/condition/gilbert-syndrome. Accessed Aug. 8, 2018.
  3. Gilbert syndrome. American Liver Foundation. https://www.liverfoundation.org/abouttheliver/info/gilbertsyndrome/. Accessed Aug. 14, 2018.
  4. Wittenberg H. Hereditary liver disease: Gallstones. Best Practice & Research Clinical Gastroenterology. 2010;24:747.
  5. Picco MF (expert opinion). Mayo Clinic, Jacksonville, Fla. March 23, 2015.