Prevalence of ΔF508 mutation in the cystic fibrosis transmembrane conductance regulator gene among cystic fibrosis patients from a Brazilian referral center.
OBJECTIVE
To verify the presence of ΔF508 mutation in the cystic fibrosis transmembrane conductance regulator gene among patients with cystic fibrosis diagnosed by the sweat test for sodium and chlorine and followed at the Pediatric Pneumology Outpatient Clinic of Universidade Estadual de Campinas, Brazil, a referral center for the treatment of cystic fibrosis.


METHODS
The study analyzed 167 DNA samples from cystic fibrosis patients. Patients' genotype was determined by polymerase chain reaction, and allele and genotype frequencies of ΔF508 mutation were calculated.


RESULTS
The genotype frequencies found for -/-, ΔF508/-, and ΔF508/ΔF508 genotypes were respectively: 43.7% (73 patients), 32.9% (55 patients), and 23.4% (39 patients). Of the 334 alleles analyzed, we observed a frequency of 201 (60.18%) alleles for the absence of ΔF508 mutation and of 133 (39.82%) for the presence of ΔF508 mutation. Hardy-Weinberg equilibrium was calculated, obtaining a chi-square value = 16.34 (p ≤ 0.001). The study population was out of equilibrium. The expected values for -/-, ΔF508/-, and ΔF508/ΔF508 genotypes were respectively: 32.22% (60.48 patients), 47.93% (80.04 patients), and 15.86% (26.48 patients).


CONCLUSIONS
In the analyzed population, ΔF508 mutation was less prevalent than the allele without this mutation. The frequency observed in this study was similar to that from other areas in Brazil and in the world, mainly due to the predominantly Caucasian origin of the population included in the study.
Genética Molecular e Citogenética, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brazil.
Andréia Marisa
AM
Bieger
Fernando Augusto de Lima
FA
Marson
Carmen Sílvia
CS
Bertuzzo
D000483:Alleles; D001938:Brazil / Q000208:ethnology; D003550:Cystic Fibrosis / Q000208:ethnology / Q000235:genetics*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D005838:Genotype; D006801:Humans; D009154:Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012017:Referral and Consultation; D044465:White People / Q000208:ethnology
C093349:cystic fibrosis transmembrane conductance regulator delta F508; D019005:Cystic Fibrosis Transmembrane Conductance Regulator