Sixty-six unrelated cystic fibrosis patients from northern Greece have been analyzed for 11 known muttions previously identified in the CFTR gene, in order to determine the spectrum of cystic fibrosis mutations in this area. Genomic DNA was extracted from blood samples and the analysis was done by means of polymerase chain reaction. This approach has allowed the detection of 80.1% of the cystic fibrosis alleles. In this region the 621+1 (G®T) mutation was found with a high frequency (12.12%), significantly different from that reported in previous studies carried out in the whole Greek population. The high frequency is likely to be due to a founder effect.

Key Words: cystic fibrosis, mutations, northern Greece, 621+1 (G®T).