IS THE MOST COMMON SERIOUS GENETIC DISEASE IN EUROPE
Cystic Fibrosis is a progressive, genetic disease present from birth throughout life due to a mutation of the CFTR gene. The CFTR gene normally determines the synthesis of a protein named CFTR (Cystic Fibrosis Transmembrane Conductance Regulator), responsible for the regular functionality of many organ secretions. People with Cystic Fibrosis have inherited two copies of the defective CF gene: one copy from each parent.
The alteration of the CFTR gene causes the excessive thickness of the mucus which involves many organs and, in particular, causes persistent lung infections in the lower airways and limits the ability to breathe over time. It obstructs pancreas and prevents pancreatic enzymes from reaching intestines, thereby stopping food from being digested and assimilated. Other organs are affected by the thickening of mucus (intestines, bile ducts, nasal tracts, reproductive system), but it is the effects on the lungs wich are the most dangerous consequence that puts people with with cystic fibrosis at risk and shortens life itself.
People born with cystic fibrosis have inherited two copies of the mutate CFTR gene, one from their father and one from their mother.The father and mother are called healthy carriers of mutated copy of this gene, which means that the gene is different from the normal one. The presence of only one copy of the mutated gene does not lead to the symptoms of the disease because the defective copy is balanced by the normal copy of the CFTR gene.
Any person who has just one mutated CFTR gene is named a “carrier” or “healthy carrier” (the two terms are synonymous).
In most cases, people who have no symptoms and do not know that they have relatives with this disease in the family, do not know that if they meet another “carrier” they are at risk of giving birth to a baby with cystic fibrosis.
It has been estimated that in Italy there is one healthy carrier of the cystic fibrosis gene for every 30 people, namely 2,000,000 people. This means that about one couple out of 900 has 2 bearers of the disease. At every pregnancy that couple has a 25% chance of giving birth to a sick child, and one baby out of 3,000 is sick. Cystic fibrosis is the most common genetic disease in all populations of European and North American origin. In African and Oriental peoples the carriers of the mutated gene are rarer and therefore the illness is less frequent.
Cystic fibrosis alters many of the secretions in many organs, which become thicker, more dehydrated and insufficiently fluid, thereby damaging these organs. It is the lungs and the pancreas that get particularly compromised. In the lower airways, this situation provides an ideal breeding ground for many microorganisms, and facilitates recurrent respiratory infections with viruses, bacteria, and fungi causing inflammations and serious infections, which then lead to a lack in the ability to breathe. Apart from insufficient breathing capacity, these symptoms burden the pancreas which cannot carry out its normal action of releasing pancreatic enzymes into the intestines: this results in defective food digestion, malabsorption, slow growth in children and poor nutritional status in adults. Over time, progressive pancreatic damage often leads to diabetes. Symptoms may damage the liver, intestines, nostrils and sperm ducts in males. Sweat glands are normally compromised and produce a very salty sweat, which makes the sweat test essential for diagnosis.
THERAPIES AND LIFE EXPECTANCY
Nowadays therapies are directed at mitigating symptoms, preventing complications, and correcting the defect at the basis of cystic fibrosis. There are internationally shared protocols which are adapted to each patient’s age and symptoms. They mostly include antibiotics for lung infections, antibiotic aerosols and secretion-thinning drugs, respiratory physiotherapy, digestive enzymes, high-calorie nutrition, and treatment of complications. A lung transplant may have to be carried out for people with irreversible lung damage.
Thanks to scientific research, therapeutic approaches have emerged that can correct the basic defects of cystic fibrosis. These drugs are called CFTR protein modulators, which are able to improve, and in some cases, even to restore the function and stability of a defective CFTR gene.
At present, there are 4 modulating drugs on the market which are effective on people with certain CFTR mutations. These pharmaceutical therapies are changing the lives of many people suffering from cystic fibrosis, with improvements in clinical and health quality.
Cystic fibrosis is a complex disease; its severity and the types of symptoms can change greatly from person to person. Many factors, such as age at diagnosis and type sof mutations, can affect the course and development of the illness.
The organization of cures and improvements in therapies reflects the evolution in research and it has brought about significant progress since the 1950s, when a child with this disease seldom reached school age. Nowadays, there more adults than children with cystic fibrosis, and they go to school and university, have a job and build a family.
The disease has a heavy impact on quality of life and life expectancy. Statistics suggest an average lifespan that exceeds 40 years: these factors are constantly improving thanks to the progress of research which aims to stop the disease from the very beginning and make the treatments we have now more effective.