title: High allelic heterogeneity between Afro-Brazilians and Euro-Brazilians impacts cystic fibrosis genetic testing.
abstract: Cystic fibrosis (CF) is an autosomal recessive disease caused by at least 1,000 different mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR). To determine the frequency of 70 common worldwide CFTR mutations in 155 Euro-Brazilian CF patients and in 38 Afro-Brazilian CF patients, we used direct PCR amplification of DNA from a total of 386 chromosomes from CF patients born in three different states of Brazil. The results show that screening for seventy mutations accounts for 81% of the CF alleles in Euro-Brazilians, but only 21% in the Afro-Brazilian group. We found 21 different mutations in Euro-Brazilians and only 7 mutations in Afro-Brazilians. The frequency of mutations and the number of different mutations detected in Euro-Brazilians are different from Northern European and North American populations, but similar to Southern European populations; in Afro-Brazilians, the mix of CF-mutations is different from those reported in Afro-American CF patients. We also found significant differences in detection rates between Euro-Brazilian (75%) and Afro-Brazilian CF patients (21%) living in the same state, Minas Gerais. These results, therefore, have implications for the use of DNA-based tests for risk assessment in heterogeneous populations like the Brazilians. Further studies are needed to identify the remaining CF mutations in the different populations and regions of Brazil.
authors.affiliation: Department of Genetics, Section of Clinical Biology, Universidade Federal do Parana, 1526 Curitiba Parana, Brazil 81531-990. genetika@genetika.com.br
authors.forename: Salmo
authors.initials: S
authors.lastname: Raskin
authors.forename: Lilian
authors.initials: L
authors.lastname: Pereira
authors.forename: Francisco
authors.initials: F
authors.lastname: Reis
authors.forename: Nelson A
authors.initials: NA
authors.lastname: Rosario
authors.forename: Norberto
authors.initials: N
authors.lastname: Ludwig
authors.forename: Lairton
authors.initials: L
authors.lastname: Valentim
authors.forename: John A
authors.initials: JA
authors.lastname: Phillips
authors.forename: Bernice
authors.initials: B
authors.lastname: Allito
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Heim
authors.forename: Elaine A
authors.initials: EA
authors.lastname: Sugarman
authors.forename: Christian M
authors.initials: CM
authors.lastname: Probst
authors.forename: Fabio
authors.initials: F
authors.lastname: Faucz
authors.forename: Lodercio
authors.initials: L
authors.lastname: Culpi
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D044383:Black People / Q000235:genetics; D001938:Brazil / Q000208:ethnology; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000235:genetics*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D018740:Genetic Heterogeneity; D005820:Genetic Testing / Q000379:methods*; D005828:Genetics, Population; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation; D044465:White People / Q000235:genetics
chemical_list: C505032:CFTR protein, human; D019005:Cystic Fibrosis Transmembrane Conductance Regulator