Gilbert’s Syndrome

Definition of Gilbert’s Syndrome

Gilbert’s syndrome abbreviated as GS, is also referred as the Gilbert–Meulengracht syndrome, familial nonhemolytic jaundice or constitutional hepatic dysfunction. This is a genetic common liver problem that is harmless.

gilbert syndrome image

The liver in GS is not processing the bilirubin very well so that it can lead to increased levels of the unconjugated bilirubin found in the bloodstream leading to hyperbilirubinemia.

GS does not create any serious consequence, with the affected person manifesting mild jaundice when having some exertional activities, when exposed to stress, after experiencing starvation or dehydration, and after alcohol consumption.

Symptoms of Gilbert Syndrome

Individuals with Gilbert’s syndrome are generally normal and do not have the clinical symptoms at all times since the bilirubin level found in the bloodstream does not stay elevated. This bilirubin can either go up but not too high, or it can also go down.

Jaundice is the characteristic symptom involving the mild yellowish discoloration of the eyes and the skin due to an elevated level of the bilirubin pigment. This sign is non-alarming if it is caused by GS.

Predisposing factors which might lead to jaundice are:

  • Presence of an infection
  • Feelings of starvation
  • Exertional activities
  • Exposure to stress
  • After surgical procedures
  • Frequent vomiting

Medications to avoid if being treated for some illness due to detoxification problems with GS:

  • Irinotecan
  • Statins with gemfibrozil
  • Gemfibrozil
  • Atazanavir and Indinavir

Other reported symptoms which are not common and not clearly related with GS:

  • Feelings of exhaustion
  • Mild abdominal pain
  • Weight loss
  • Itchiness with no rashes
  • Loss of appetite
  • Mild body weakness and fatigue
  • Mild feelings of getting nauseated
  • Problem in maintaining concentration

GS is believed according to some reports to contribute to the rapid start of neonatal jaundice such as in cases of G6PD deficiency. This needs urgent intervention since the elevated bilirubin here can lead to the development of kernicterus which is an irreversible neurological problem.

GS patients who may have mild bilirubin elevated level are found to have a minimal risk to develop coronary artery disease (CAD) and with lesser chances to have future cardiac ailments. However, a person with GS has been linked to an increased risk of developing gallstones.

Causes of Gilberts Syndrome

Gilbert syndrome has a phenotypic effect with its genetic mutation for the enzyme UGT1A1 which is necessary for the metabolism of bilirubin and is being presented by mild jaundice as a result of an increase in the unconjugated bilirubin.

GS has been characterized by a reduction of about 70-80% glucuronidation activity of the UGT1A1 gene in the promoter region of a gene and is located on chromosome 2. The UGT1A1 gene plays a major role in producing a protein that converts the unconjugated bilirubin into its nontoxic form which is the conjugated bilirubin.

Patients who are found to have two copies of the defective abnormal promoter region known to be inherited from each parent for the UGT1A gene have GS and bilirubin levels are also increased.

This makes GS to be a common hereditary problem. It has been noted that there is 1 person in a group of 20 has the GS as a problem, although there is that 1 individual person from the 3 who are having GS is not aware to have the health condition. This is usually noted by chance during the performance of routine blood screening examinations.

gilberts syndrome pathology

Diagnosis of Gilberts Syndrome

GS is most easily and commonly diagnosed after the puberty stage because of some changes in the levels of the sex hormones that leads to the rising of bilirubin levels in the blood.

Confirmation of GS is based on:

  • Blood tests are done to measure the levels of bilirubin in order to confirm GS because the occurrence of jaundice can be a result of other liver and blood diseases.
  • Liver function tests can also be done to assess the liver. A damaged liver releases enzymes going into the blood and there will be a decrease of protein produced by the liver. The measurement of protein and enzyme levels can give a clear picture of liver function. GS presents high levels of bilirubin in the blood while the liver is maintaining its normal function.
  • Genetic testing might also be done to confirm the diagnosis of GS.

It has been recorded that patients who have GS have an elevated level of the unconjugated bilirubin, while the conjugated bilirubin level is mostly within the normal range and lesser than 20% of the total.

GS patients have bilirubin levels between 20 μM to 90 μM (1.2 to 5.3 mg/dl) as being compared to the normal level of < 20 μM. The ratio of unconjugated/conjugated bilirubin level is mostly higher than those without GS.

Bilirubin level is also increased when the blood sample is extracted from a patient who did a two-day fasting, thus, the fasting act and its result can be utilized to diagnose a GS.

Treatment of Gilberts Syndrome

Patients with GS do not need any treatment since they can have a healthy and normal ways of living like the others. It does not make a significant effect on life expectancy.

There is no need to make modifications on the regular diet and exercise regimen. This means that the standard healthy diet recommendation can be followed along with healthy exercise.

Studies have considered the positive effect of applying the Paloelithic ketogenic diet with animal fat, meat, offal, eggs, fruits and vegetables. This can lower down results of the total and direct bilirubin levels with values below the upper reference limit.

It is just very important to prevent the triggering factors like exertional activities or the situations related to stress to prevent a GS.


  4. Tóth, Csaba, and Zsófia Clemens. Gilbert’s Syndrome Successfully Treated with the Paleolithic Ketogenic Diet. American Journal of Medical Case Reports 3.4 (2015): 117-120.
  5. Lin JP; O’Donnell CJ; Schwaiger JP; et al. (2006). “Association between the UGT1A1*28 allele, bilirubin levels, and coronary heart disease in the Framingham Heart Study”. Circulation 114 (14): 1476–81.
  6. Boon et al (2006). Davidson’s Principles & Practice of Medicine, 20th edition, Churchill Livingstone.

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