It is a mild genetic liver disorder in which the body can not properly process bilirubin.
A yellowish waste product is formed when old or worn-out red blood cells break down (hemolysis).
People with Gilbert syndrome have elevated bilirubin levels because they have a reduced degree of a specific liver enzyme needed for the removal of bilirubin.
Most affected individuals have no symptoms (asymptomatic) or only show a slight yellowing of the skin, mucous membranes, and whites of the eyes (jaundice).
In some individuals, jaundice can only be apparent when triggered by these conditions.
Gilbert’s syndrome is a genetic condition inherited as an autosomal recessive trait.
Genetic diseases are determined by the combination of genes for a particular trait found in the chromosomes received from both the father and the mother.
Researchers have determined that mutations in the UGT1A1 gene cause Gilbert’s syndrome.
This gene contains instructions for creating (coding) a liver enzyme known as uridine diphosphate-glucuronosyltransferase-1A1 (UGT1A1).
Bilirubin circulates in the blood (plasma) bound to a protein called albumin, in the form of unconjugated bilirubin, which does not dissolve in water (insoluble in water).
Usually, this unconjugated bilirubin is absorbed by the liver cells. With the help of the enzyme UGT1A1, it is converted into bilirubin glucuronides soluble in water (conjugated bilirubin), which are then excreted in the bile.
Bile is stored in the gallbladder. When requested, it passes into the common bile duct and then into the upper portion of the small intestine (duodenum) and aids digestion, and eventually exits the body through the stool.
Symptoms of Gilbert’s syndrome
About one in three people with Gilbert’s syndrome does not experience any symptoms.
Therefore, you may not realize that you have the syndrome until tests are done for an unrelated problem.
Most people with Gilbert’s syndrome experience occasional, short-lived episodes of jaundice (yellowing of the skin and whites of the eyes) due to the buildup of bilirubin in the blood and may not appear until adolescence.
These episodes are usually mild and occur when the body is under stress, for example, due to dehydration, prolonged periods without food (fasting), illness, strenuous exercise, or menstruation.
Some people with Gilbert’s syndrome also experience abdominal discomfort or fatigue.
However, approximately 30 percent of people with Gilbert’s syndrome have no signs or symptoms of the disease and are discovered only when routine blood tests reveal elevated levels of unconjugated bilirubin.
People with Gilbert syndrome are usually diagnosed in late adolescence or early twenties.
The diagnosis is based on slightly elevated levels of conjugated bilirubin in the blood and the appropriate clinical situation.
The elevated level of bilirubin observed in routine laboratory tests can be diagnosed by a blood test to measure bilirubin levels and a liver function test.
When the liver is damaged, it releases enzymes in the blood; simultaneously, the protein levels that the liver produces to keep the body healthy begin to decrease.
By measuring the levels of these enzymes and proteins, it is possible to construct a reasonably accurate picture of how well the liver is functioning.
If the test results show that you have high bilirubin levels in your blood but your liver is functioning normally, you can usually make a reliable diagnosis of Gilbert’s syndrome.
In some cases, a genetic test may be necessary to confirm a diagnosis of Gilbert’s syndrome.
Treatment for Gilbert’s syndrome
In most cases, Gilbert’s syndrome does not cause symptoms, and no treatment is necessary, but it is essential to ensure that the person does not have another more serious condition.