CYSTIC FIBROSIS (CF)

Scientific Background

Cystic fibrosis (CF) is one of the most common autosomal recessive inherited diseases in the Caucasian population (frequency 1:2500, frequency of carriers 1:25). Affected persons suffer from chronic pulmonary symptoms (frequent bronchopulmonary infections, persistent bronchiectasis) and gastrointestinal symptoms (pancreatic insufficiency, pancreatitis, meconium ileus (pre- or neonatal)), and male infertility is seen. It is caused by pathogenic changes in the CFTR (cystic fibrosis transmembrane conductance regulator) gene, which leads to the functional disruption of a chloride channel in the apical membrane of glandular epithelial cells and thus to a change in the salt content of sweat and other body secretions.

The most frequently detected pathogenic alteration of the CFTR gene in many populations is the variant p.Phe-508del (F508del). There are >2000 other pathogenic changes in the CFTR gene currently described that are significantly less frequent. The development of the disease depends on the type and severity of the CFTR variants. In addition to the classical, early manifesting and multisystemic cystic fibrosis, milder, monosymptomatic forms have also been described and are grouped under the so-called CFTR-RDs (related disorder). These include disseminated bronchiectasis, atypical chronic rhinosinusitis, chronic pancreatitis or CBAVD (congenital bilateral aplasia of the vas deferens).

Early diagnosis is of great importance with regard to optimal care of those affected. Molecular genetic diagnostics to confirm the suspected clinical diagnosis and determine the CFTR genotype can have a decisive influence on the later choice of therapy. CF diagnostics have also been part of newborn screening since 2016.

References

Goetz et Ren 2019, Pediatr Ann 48:e154 / Wiencek et Lo 2018, Clin Chem 64:898 / Sosnay et al. 2017, J Pediatr 181S:S52 / Farrell et al. 2017, J Pediatr 181S:S4 / Dequeker et al. 2009, Eur J Hum Genet 17:51 / Castellani et al. 2008, J Cyst Fibros 7:179 / Ogino et al. 2004 J Med Genet 41:e70 / Steiner et al. 2004, Hum Mutat 24:120 / Bobadilla et al. 2002, Hum Mutat 19:575 / Claustres et al. 2000, Hum Mutat 16:143