Mucoviscidosis

What is mucoviscidosis?

It is characterized by a mutation in a gene (CFTR) coding for a protein responsible for transporting chlorine through cell membranes throughout the body.

Chlorine cannot circulate normally and this results in increased viscosity of the mucous secretions of the pulmonary and digestive surfaces. The secretions accumulate and cause obstructions, which can become infected.

It affects one child out of 3,500 in European countries.

How is it transmitted?

It is an inherited autosomal recessive genetic disease. It is transmitted in an autosomal recessive manner, i.e. the gene responsible for the disease is recessive.

In order for the disease to manifest itself, a child must have inherited two defective (recessive) genes, one from each parent.

If the parents are not sick, they are considered to be “carriers” of this recessive gene.

What are the symptoms?

The disease affects the lungs, liver and other organs such as the pancreas (insulin-dependent diabetes), the genitals (fertility issues) and the upper respiratory tract (nasal polyposis).

The liver can also be affected through an increase in bile viscosity due to the CFTR protein abnormality in the bile ducts.

The bile, which is too viscous, accumulates and leads to multiple obstructions in the bile ducts, which can lead to cirrhosis.

Cirrhosis makes it difficult for blood to pass through the liver, which leads to an accumulation of blood in intra-abdominal organs.

This is called portal hypertension,with symptoms that include an increase in the size of the abdomen, a delay in weight gain, and in the most advanced cases, the risk of digestive bleeding. 

Liver damage is rarely associated with yellow skin discoloration (jaundice) or liver failure.

How is it diagnosed?

The diagnosis of cystic fibrosis is based on a so-called “perspiration” test to assess whether the secretion of chlorine is increased, and it can be confirmed by searching for the CFTR genetic mutation.

What are the treatments?

There is no cure. Treatments focus on symptom relief:

• At the pulmonary level, daily physiotherapy is often indicated, as well as hospitalizations for antibiotic treatment due to superinfections by bacteria.
• For liver damage, vitamins and ursodeoxycholic acid are prescribed
• For pancreatic damage, pancreatic enzymes are administered.

Depending on the situation, a transplant may be proposed, either only pulmonary, or only of the liver, or transplantation of both organs.

A liver transplant can cure the genetic anomaly in the liver, so there is no recurrence of the liver disease.

On the other hand, pulmonary and endocrinological lesions persist after a liver transplant alone, and will require the same monitoring as before the transplant.