title: Polymorphic markers suggest a gene flow of CFTR gene from Sub-Saharan/Arabian and Mediterranean to Brazilian Population.
abstract: The analysis of 2 diallelic loci (M470V and T854T) and a microsatellite IVS8(T)n of the cystic fibrosis transmembrane conductance regulator (CFTR) gene has shown different haplotype distribution in Brazilian cystic fibrosis (CF) chromosomes carrying different CF mutations. The DeltaF508 mutation was in absolute linkage disequilibrium with 1-1 haplotype (M470V-T854T). Most of DeltaF508 chromosomes (84%) were found to carry the IVS8-9T. The most frequent haplotypes IVS8-7T and 2-1 (M470V-T854T) were found associated with Non-DeltaF508 mutations. Although there is a remarkable linkage disequilibrium between these markers with CFTR locus, the mutations R334W (7T-1-2 and 7T-2-1) and the 3120 + 1G --> A (7T-1-2 and 9T-1-2) are associated with two different haplotypes probably introduced in the Brazilian population by migration. These findings suggest that recombination events from the original haplotype and gene flow among different ethnic groups (sub-Saharan and Mediterranean) might have resulted in CF mutations associated with different haplotypes by independent introductions.
authors.affiliation: Laboratório de Genética Humana, Instituto Oswaldo Cruz, FIOCRUZ, Av. Brasil, 4365 Manguinhos, 21040-900 Rio de Janeiro, Brasil. gkalil@ioc.fiocruz.br
authors.forename: Giselda M K
authors.initials: GM
authors.lastname: Cabello
authors.forename: Pedro H
authors.initials: PH
authors.lastname: Cabello
authors.forename: Juan C
authors.initials: JC
authors.lastname: Llerena
authors.forename: Octavio
authors.initials: O
authors.lastname: Fernandes
mesh_terms: D017954:Africa South of the Sahara; D001938:Brazil; D002869:Chromosome Aberrations; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D004641:Emigration and Immigration; D019143:Evolution, Molecular; D051456:Gene Flow; D005787:Gene Frequency; D005819:Genetic Markers; D005828:Genetics, Population; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium; D019083:Mediterranean Region; D018895:Microsatellite Repeats; D008877:Middle East; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length
chemical_list: C505032:CFTR protein, human; D005819:Genetic Markers; D019005:Cystic Fibrosis Transmembrane Conductance Regulator