Cyprus is an island in the eastern Mediterranean basin inhabited by people of 
Caucasian extraction, mostly Greek-Cypriots. The most common inherited disease 
among Caucasians is cystic fibrosis (CF). Although no careful scientific study 
had ever been done the impression was that CF was extremely rare among the 
Greek-Cypriots, with an incidence estimated at around 1:30,000. About 2 years 
ago, we introduced molecular diagnostic methodology in an effort to assist 
clinicians in safer diagnosis of patients presenting with atypical CF 
symptomatology, and also for testing the hypothesis that mutations that cause 
milder phenotypes might be responsible for misdiagnosis or for missing entirely 
some cases of CF. Initial screening for delta F508 revealed that it is indeed 
rare in the general population. Further screening of suspected CF patients 
revealed a novel mutation that converted leucine at position 346 to proline 
(L346P) in two unrelated families. The second CF mutation was delta F508 and 
1677delTA in the two families respectively, both reportedly associated with 
severe phenotypes. Yet our patients did not present with typical CF pictures 
possibly because of the dominant nature of this novel mild mutation in exon 7. 
Symptoms included failure to thrive, chest infections and electrolyte 
disturbances. These findings raise the possibility that Cyprus might have been 
spared very severe CF phenotypes but not cystic fibrosis transmembrane 
conductance regulator (CFTR) mutations.