title: Relationship between genotypes of the Duffy blood groups and malarial infection in different ethnic groups of Choco, Colombia.
abstract: BACKGROUND
  The negative homozygous condition for the Duffy blood group (Fy-/Fy-) confers natural resistance to Plasmodium vivax infection. Studies carried out in pursuing this direction in Colombia are scarce.
  
  
  OBJECTIVE
  To describe the relationship between Duffy genotypes in three ethnic communities of La Italia (Chocó) and malarial infection.
  
  
  METHODS
  This is a descriptive, cross-sectional study in symptomatic and asymptomatic subjects with malaria.
  
  
  METHODS
  Afro-Colombians 73; Amerindian (Emberá) 74, and Mestizo, 171. The presence of Plasmodium infection was assessed by thick smear and the status of the Duffy gene was studied by PCR and RFLP to help identify changes to T-46C and A131G which originate the genotypes T/T, T/C , C/C and G/G, G/A, A/A.
  
  
  RESULTS
  Infection by Plasmodium was detected in 17% of cases with 62% due to P. falciparum and 27% due to P. vivax. Duffy genotypes were significantly associated with ethnicity (p= 0.003). Individuals with the C/C, A/A diplotypes were exclusively infected by P. falciparum, whereas the other diplotypes were infected with either of the species. In the Amerindian and Mestizo populations, the frequency of the T-46 allele was 0.90-1.00, among Afro-Colombians this was 0.50, the same as with the C allele and with an absence of heterozygous. At locus 131, the maximum frequency of the G allele was 0.30 in Amerindians and the maximum of the A allele was 0.69 in Afro-Colombians.
  
  
  CONCLUSIONS
  In the Amerindian and mestizo populations studied, there was a predominance of the allele T-46 (FY+) but this was not observed with the P. vivax infection. P. vivax was ruled out in all FY- individuals.
authors.affiliation: Universidad de Antioquia, Medellin, Colombia.
authors.forename: Lina
authors.initials: L
authors.lastname: Gonzalez
authors.affiliation: Universidad de Antioquia, Medellin, Colombia.
authors.forename: Jorge
authors.initials: J
authors.lastname: Vega
authors.affiliation: Universidad de Antioquia, Medellin, Colombia.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Ramirez
authors.affiliation: Universidad de Antioquia, Medellin, Colombia.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Bedoya
authors.affiliation: Universidad de Antioquia, Medellin, Colombia.
authors.forename: Jaime
authors.initials: J
authors.lastname: Carmona-Fonseca
authors.affiliation: Universidad de Antioquia, Medellin, Colombia.
authors.forename: Amanda
authors.initials: A
authors.lastname: Maestre
keywords: Colombia; Duffy blood-group system; PCR-RFLP; Plasmodium falciparum; Plasmodium vivax; ethnic groups; genotypes; malaria