FREQUENCY OF THE CYSTIC-FIBROSIS DELTA-F-508 MUTATION IN A POPULATIONFROM SAO-PAULO STATE, BRAZIL

Cystic fibrosis (CF) nonrelated patients (N = 24) from Sao Paulo State , Brazil, were screened for the presence of the DELTAF 508 mutation by PCR amplification of the deletion region with the primers C16B(5'GTTT TCCTGGATTATGCCTGGGCAC3') and C16D (5'GTTGGCATGCTTTGAT-GACGCTTC3') and by acrylamide gel electrophoresis.The allelic frequency of the DELTAF 508 mutation was 33 % (15/48 chromosomes). The genotype distribution a mong the patients showed 12.5 % (N = 3) of DELTAF 508 homozygotes, 37. 5 % (N = 9) of DELTAF heterozygotes and 50 % (N = 12) of non-carriers of the mutation. The frequency observed in this study is lower than th at estimated for the North American and North European population (75 % to 80 %) and is similar to that described in Southern Europe (25 % t o 50 %) which is consistent with the origins of this population.