Genotypic hetereogeneity of the molecular basis of cystic fibrosis: the paradigm of lithuanian population genetic testing

Since cystic fibrosis (CF) is the most common lethal hereditary monogenic disease in Caucasian populations with an average prevalence of 1:2500 newborns, population screening by genetic testing for CF prenatal diagnosis and clinical phenotype determination seems worthwhile to implement in all countries as is the case for other common inherited disease screening protocols. Worldwide mutational analysis of the CF transmembrane regulator (CFTR) gene has revealed that p.F508del mutation accounts on the average for 70-80% of CF chromosomes from northern Europe and America. Yet, more than 1500 mutations of CFTR have been identified to cause CF in different populations. In addition, the phenotypic spectrum associated with mutations in the CFTR gene extends beyond the classically defined CF. Due to the high allelic and phenotypical heterogeneity of CF chromosomes, it is important to identify the CFTR mutation