title: Distribution of QPY and RAH haplotypes of granzyme B gene in distinct Brazilian populations.
abstract: BACKGROUND
  The cytolysis mediated by granules is one of the most important effector functions of cytotoxic T lymphocytes and natural killer cells. Recently, three single nucleotide polymorphisms (SNPs) were identified at exons 2, 3, and 5 of the granzyme B gene, resulting in a haplotype in which three amino acids of mature protein Q48P88Y245 are changed to R48A88H245, which leads to loss of cytotoxic activity of the protein. In this study, we evaluated the frequency of these polymorphisms in Brazilian populations.
  
  
  METHODS
  We evaluated the frequency of these polymorphisms in Brazilian ethnic groups (white, Afro-Brazilian, and Asian) by sequencing these regions.
  
  
  RESULTS
  The allelic and genotypic frequencies of SNP 2364A/G at exon 2 in Afro-Brazilian individuals (42.3% and 17.3%) were significantly higher when compared with those in whites and Asians (p < 0.0001 and p = 0.0007, respectively). The polymorphisms 2933C/G and 4243C/T also were more frequent in Afro-Brazilians but without any significant difference regarding the other groups. The Afro-Brazilian group presented greater diversity of haplotypes, and the RAH haplotype seemed to be more frequent in this group (25%), followed by the whites (20.7%) and by the Asians (11.9%), similar to the frequency presented in the literature.
  
  
  CONCLUSIONS
  There is a higher frequency of polymorphisms in Afro-Brazilians, and the RAH haplotype was more frequent in these individuals. We believe that further studies should aim to investigate the correlation of this haplotype with diseases related to immunity mediated by cytotoxic lymphocytes, and if this correlation is confirmed, novel treatment strategies might be elaborated.
authors: Universidade Federal do Triângulo Mineiro, Uberaba, MG, Brasil. nandadelli@yahoo.com.br
authors: Fernanda Bernadelli
authors: FB
authors: Garcia
authors: Simone
authors: S
authors: Kashima
authors: Evandra Strazza
authors: ES
authors: Rodrigues
authors: Israel Tojal
authors: IT
authors: Silva
authors: Tathiane Maistro
authors: TM
authors: Malta
authors: Larissa Deadame de Figueiredo
authors: LD
authors: Nicolete
authors: Dimas Tadeu
authors: DT
authors: Covas
authors: Helio
authors: H
authors: Moraes-Souza
mesh_terms: D044466:Asian People / Q000235:genetics*; D044383:Black People / Q000235:genetics*; D001938:Brazil / Q000208:ethnology; D005787:Gene Frequency; D005828:Genetics, Population; D005838:Genotype; D053804:Granzymes / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D044465:White People / Q000235:genetics*
chemical_list: D053804:Granzymes