title: Admixture estimates for Churuguara, a Venezuelan town in the State of Falcón.
abstract: BACKGROUND
  The present Venezuelan population is the admixture product of Amerindians, Europeans and Africans, a process which was not homogeneous over the country. Blood groups, STRs and VNTRs, specifically D1S80, have been used successfully in admixture studies, but few have been made in Venezuela.
  
  
  OBJECTIVE
  This study aims to estimate the admixture components of Churuguara, Venezuela, and to evaluate the genetic relationship of this population with other Venezuelan as well as worldwide populations through principal component analysis and the study of dendrograms based on genetic distances.
  
  
  METHODS
  Gene frequencies of blood groups ABO and Rh (only anti D), of STRs VWA, F13A01, FES/FPS and VNTR D1S80 were studied in a sample of 60 individuals born in Churuguara, a Venezuelan town of admixed ancestry in the State of Falc6n. Admixture was estimated with Chakraborty's gene identity method, and Nei's standard genetic distance was used to build two dendrograms with the neighbour-joining approach, one based on the three STRs and the other based only on D1S80. Principal component analyses with the gene frequencies of these markers were also performed.
  
  
  RESULTS
  The frequency of allele ABO*O was 0.788, of ABO*A was 0.187 and of RH*D was 0.74. D1S80 showed 16 different alleles with a heterozygosity of 0.880, whilst the three STRs showed only eight different alleles and heterozygosities between 0.733 and 0.797. The estimates of admixture obtained in this analysis were 52.5% for the Spanish parental group, 27.6% for the African and 19.9% for the Amerindian. Comparison of Churuguara with other Latin American populations shows that its African component is not as high as that observed in Colombian Choco, but it is higher than that observed in other samples from Colombia, Chile and Maracaibo (Venezuela).
  
  
  CONCLUSIONS
  Results of the admixture analysis are consistent with those obtained with two dendrograms and principal component analyses, suggesting that the strong initial Amerindian component of 500 years ago has been diluted by the continuous flow of European genes, mainly Spanish, to this region.
authors.affiliation: Laboratorio de Genética Humana, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
authors.forename: M Acosta
authors.initials: MA
authors.lastname: Loyo
authors.forename: D Castro
authors.initials: DC
authors.lastname: de Guerra
authors.forename: M H
authors.initials: MH
authors.lastname: Izaguirre
authors.forename: A
authors.initials: A
authors.lastname: Rodriguez-Larralde
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D044467:American Indian or Alaska Native / Q000235:genetics; D044383:Black People / Q000235:genetics; D005787:Gene Frequency; D005828:Genetics, Population; D006801:Humans; D012204:Rh-Hr Blood-Group System / Q000235:genetics*; D020080:Tandem Repeat Sequences / Q000235:genetics; D014687:Venezuela; D044465:White People / Q000235:genetics
chemical_list: D000017:ABO Blood-Group System; D012204:Rh-Hr Blood-Group System