WHAT IS CYSTIC FIBROSIS?
Cystic fibrosis is the second most common genetic disease in Europe. Sufferers experience significantly shorter life expectancy and high morbidity due to the production of viscous secretions in the respiratory and gastrointestinal systems, which lead to gradual destruction of organs in these systems (lungs, pancreas, etc.).
In cystic fibrosis, due to gene mutations, a change is made in a protein called the cystic fibrosis transmembrane conduction regulator (CFTR). This protein is responsible for transporting chloride from inside to outside of the membrane.
Testing for cystic fibrosis mutations is mandatory in infertile couples. Of primary interest is of course the health of the fetus: if the parents are both carriers of a cystic fibrosis mutation then the fetus will suffer from cystic fibrosis, which is a very serious disease. If a mutation is found in one parent, it is necessary for the other parent to do the test to prevent the transmission of the disease to the fetus.
Men diagnosed with azoospermia are always tested for mutations of the cystic fibrosis gene: if a mutation exists one or both spermatic cords may be absent and this is the cause of azzospermia.
HOW IS CYSTIC FIBROSY TESTED?
More than 2000 mutations in the CFTR gene have been identified, with the Δf508 mutation being the most common one. The mutation Δf508 covers only 50% of cases of this serious disease, so it is advised to test the entire gene for mutations using the next-generation sequencing (NGS).
FISH on sperm
Y chromosome microdeletions (AZF)