Dombrock genotyping in Brazilian blood donors reveals different regional frequencies of the HY allele.
BACKGROUND
Dombrock blood group system genotyping has revealed various rearrangements of the Dombrock gene and identified new variant alleles in Brazil (i.e., DO*A-SH, DO*A-WL and DO*B-WL). Because of the high heterogeneity of the Brazilian population, interregional differences are expected during the investigation of Dombrock genotypes.


OBJECTIVE
The present study aims to determine the frequencies of Dombrock genotypes in blood donors from Minas Gerais and compare the frequencies of the HY and JO alleles to those of another population in Brazil.


METHODS
The frequencies of the DO alleles in Minas Gerais, a southeastern state of Brazil, were determined from the genotyping of 270 blood donors. Genotyping involved polymerase chain reaction and restriction fragment length polymorphism analysis to identify the 323G>T, 350C>T, 793A>G, and 898C>G mutations, which are related to the HY, JO, DO*A/DO*B, and DO*A-WL/DO*B-WL alleles, respectively. Moreover, the frequencies of rare HY and JO alleles were statistically compared using the chi-square test with data from another Brazilian region.


RESULTS
The HY allele frequency in Minas Gerais (2.4%) was almost twice that of the JO allele (1.5%). The frequency of the HY allele was significantly higher (p-value = 0.001) than that in another Brazilian population and includes a rare homozygous donor with the Hy- phenotype. In addition, the DO*A-WL and DO*B-WL alleles, which were first identified in Brazil, were found in the state of Minas Gerais.


CONCLUSIONS
The data confirm that the frequencies of DO alleles differ between regions in Brazil. The population of Minas Gerais could be targeted in a screening strategy to identify the Hy- phenotype in order to develop a rare blood bank.
Universidade Federal de Minas Gerais - UFMG, Belo Horizonte, MG, Brazil.
Fabiana Chagas Camargos
FC
Piassi
Universidade Federal de Minas Gerais - UFMG, Belo Horizonte, MG, Brazil.
Silvana Maria Eloi
SM
Santos
Centro de Hematologia e Hemoterapia, Hemocentro da UNICAMP, Universidade Estadual de Campinas - UNICAMP, Campinas, SP, Brazil.
Lilian Maria
LM
de Castilho
Hemocentro da Faculdade de Medicina de Marília - FAMEMA, Marília, SP, Brazil.
Wilson
W
Baleotti Júnior
Hemocentro da Faculdade de Medicina de Marília - FAMEMA, Marília, SP, Brazil.
Rodrigo Buzinaro
RB
Suzuki
Fundação Centro de Hematologia e Hemoterapia de Minas Gerais - Hemominas, Belo Horizonte, MG, Brazil.
Débora Moura
DM
da Cunha
Alleles; Blood donors; Blood group antigens; Brazil; Genotyping techniques; H-Y antigen/blood; Phenotype; Polymerase chain reaction; Polymorphism, restriction fragment length