Cystic Fibrosis – Present and Future

Why is it so important to talk about this disease, which affects around 42,000 people in the European Union?

Cystic Fibrosis is a genetic, chronic and progressive disease, which occurs due to a dysfunction of the body's exocrine glands. It causes the production of abnormally thick and sticky mucous secretions, and sweat with a high concentration of salt.

This disease, although rare, affects about 1 in every 7,000 people in Portugal, and it is estimated that every year around 30 to 40 children are born with Cystic Fibrosis in the country.

The disease is caused by a genetic mutation, and it is hereditary, transmitted from parents to children. However, for the disease to manifest itself, the mutated gene must be inherited from both parents.

Although there is still no cure, early diagnosis is essential. A timely clinical intervention allows for a significant reduction in the problems associated with the disease, a considerable improvement in the quality of life and an increase in the average life expectancy of patients – currently situated between 35 and 40 years of age.

Since 2013, neonatal screening for Cystic Fibrosis has been made possible and widely available, as it has been included in the panel of diseases of the Programa Nacional de Diagnóstico Precoce (National Program for Early Diagnosis) in Portugal, known as the heel prick test.

At the Dr. Joaquim Chaves Saúde’s Clinical Analysis Laboratory’s Medical Genetics Service, it is possible to carry out the laboratory diagnosis of Cystic Fibrosis using a set of complementary tests.

Carrier testing should be performed by couples when one or two members of the couple have a higher risk of being a carrier of the mutated gene – even if it does not manifest itself. This test is recommended when there are cases of the disease in the family, or when a first child has already been diagnosed with the pathology, within the scope of a medical genetic consultation.

In the case of pregnancy, and with the appearance of non-invasive genetic tests, it is currently possible to offer genetic diagnosis of the fetus to couples carrying the known mutation in the gene, starting at 12 weeks of gestation. Prenatal genetic diagnosis is also possible, through the search for gene mutations obtained in samples of chorionic villus sampling (CVS), collected at 13 weeks of gestation, or by amniocentesis from 16 weeks of gestation. 

For postnatal diagnoses, in a first phase, the sweat test is performed, which is a simple screening to measure the levels of sodium chloride in sweat. In the case of two positive tests, a genetic test is performed. This consists of a DNA analysis, obtained from a blood sample, in which the most frequent mutations are sought. Complete gene sequencing is only carried out when necessary.

The Joaquim Chaves Saúde Group has Medical Genetics consultations available in its clinics, in which it one can obtain the clinical diagnosis of the disease, as well as seek adequate genetic counseling.

Genetic counseling assesses personal and family risk, as well as clinical guidance for couples or individuals who are carriers, or at risk of being carriers, of the disease.