In a person with Gilbert-Meulengracht syndrome, the liver is not able to constantly process a brown-yellow pigment in the bile, the so-called bilirubin.
This leads to an increased level of bilirubin in the blood (hyperbilirubinemia) and causes jaundice, a characteristic yellowing of the skin and eyes.
Despite the yellowish appearance of the patient, the liver functions normally.
Gilbert-Meulengracht syndrome does not lead to cirrhosis, fatty liver or liver tumor.
When the liver functions properly, it filters impurities and toxins from the body, processes proteins and carbohydrates, and breaks down fats through the bile stored in the gallbladder.
Gilbert-Meulengracht syndrome is usually detected in adolescence.
People with this condition have episodes of mild hyperbilirubinemia, which occurs when the body experiences stress (dehydration, long fasting, illness, intense physical activity, or menstruation).
Causes of Gilbert-Meulengracht syndrome
Gilbert-Meulengracht syndrome is an inherited condition caused by an abnormal gene.
This gene controls an enzyme that serves to break down bilirubin in the liver.
If this gene is ineffective, an excess amount of bilirubin accumulates in the blood. The disease does not spread from person to person and it is not an infectious disease.
How is bilirubin processed?
Bilirubin is a yellowish pigment that is formed when the body breaks down the old red blood cells.
The bilirubin travels through the bloodstream to the liver. This shift occurs by binding to a protein called ligandin.
Normally, an enzyme in the liver cells breaks down the bilirubin and removes it from the bloodstream.
The bilirubin, along with bile, travels from the liver to the intestine and is then excreted in the stool.
A small amount of bilirubin remains in the bloodstream.
How does the transmission of the abnormal gene to the child occur?
The genetic defect that causes Gilbert-Meulengracht syndrome is widespread.
Many people have one copy of this abnormal gene in their DNA, but it takes two copies to cause Gilbert-Meulengracht syndrome.
What genes are associated with Gilbert-Meulengracht syndrome?
Mutations attached to the UGT1A1 gene can cause Gilbert-Meulengracht syndrome.
These genes contain the instructions to make an enzyme called UDP-glucuronosyltransferase (UDP-GT).
This enzyme is mainly found in the liver cells and is required to remove bilirubin from the body.
The enzyme UDP causes a chemical reaction called glucuronidation. In this reaction, the enzyme transfers the glucuronic acid to unconjugated bilirubin and turns it into conjugated bilirubin.
Glucuronidation makes bilirubin water-soluble and thus it can be excreted from the body.
People with Gilbert-Meulengracht syndrome have about 30% functioning UDP enzymes. As a result, the unconjugated bilirubin does not glucuronidate fast enough. This toxic substance thus accumulates in the body and causes increased bilirubin levels.
However, not all people with a genetic mutation develop hyperbilirubinemia. At the same time, it is necessary to refer to other diseases that impede the process of glucuronidation.
For example, red blood cells can break down far too quickly and release more bilirubin, which cannot be processed by the altered enzyme.
In addition, the transport of bilirubin to the liver may be altered. These factors may be caused by changes in other genes.
What are the symptoms of Gilbert-Meulengracht syndrome?
Most people affected by Gilbert-Meulengracht syndrome do not know this. Bilirubin levels are within the normal range and only increase slightly in rare cases.
The main symptom is jaundice: a shade that tends to turn yellowish both on the skin and in the eyes when bilirubin increases.
Symptoms may become more evident with:
- too hard training (excessive efforts).
Even though bilirubin levels almost never reach dangerous levels, the jaundice that occurs can be troubling.
Gilbert-Meulengracht syndrome can manifest itself with the following symptoms:
- loss of appetite,
- dark urine,
- Stomach ache.
Diagnosis of Gilbert-Meulengracht syndrome
Gilbert-Meulengracht syndrome is suspected if the patient has elevated levels of unconjugated bilirubin without any apparent cause.
The doctor may order various blood tests and an echography of the liver to make sure there is no other medical cause for it.
The level of bilirubin in the blood can change rapidly, so it is recommended to repeat the examinations at least twice.
Laboratory DNA testing can confirm the diagnosis made, although genetic testing is not always available and required.
The levels of other liver enzymes (gamma GT, AST and ALT) are not altered.
Gilbert-Meulengracht syndrome in infants and children
Newborns produce more bilirubin compared to adults because their red blood cells have a shorter lifespan and the renewal of these cells is much faster.
As a result, more red blood cells die in infants than in adults, so a greater amount of bilirubin is formed when the blood cells are broken down.
As a result, infants have physiological neonatal jaundice, but if they also suffer from Gilbert-Meulengracht syndrome, the situation becomes much more serious.
What is the therapy for Gilbert-Meulengracht syndrome?
Gilbert-Meulengracht syndrome does not require treatment.
People with Gilbert-Meulengracht syndrome lead normal and healthy lives.
This condition does not affect life expectancy.
Sometimes jaundice can occur for a short time, but it is not a health problem.
Barbiturates can temporarily reduce jaundice, but this is associated with significant side effects and it is better to talk to your doctor about it.
In the case of Gilbert-Meulengracht syndrome, the following medications should be avoided:
- atazanavir and indinavir (used to treat HIV infection)
- Gemfibrozil (a drug used to lower elevated blood lipids)
- statins (a cholesterol-lowering medicine) when taken with gemfibrozil
- Irinotecan (used to treat advanced colorectal cancer)
Diet and nutrition for Gilbert-Meulengracht syndrome
- Legumes, nuts, seeds, fruits and vegetables, beetroot, artichokes, carrots, turmeric and lecithin should be included in the diet. 40% of the diet should consist of raw fruits and vegetables (especially green leafy vegetables).
- Drink eight glasses of water or, if desired, lemon water a day.
- Processed or refined foods, refined sugar, fatty and fried foods, junk food, coffee, black tea and soft drinks should be avoided. Do not eat oversized portions, prefer to eat small and regular meals.
- Avoid margarine or similar products derived from hydrogenated fats.
- Avoid artificial sweeteners.
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