title: Gene frequencies of human neutrophil antigens 4a and 5a in the korean population.
abstract: BACKGROUND
  In Korean population, antigen frequencies of HNA-1a, HNA-1b, and HNA-2a are determined using a serological and genotyping method. However, no study has been done to assess the gene frequencies of HNA-4a and HNA-5a. It has been reported that the antibody against HNA-4a is associated with alloimmune neutropenia and autoimune neutropenia; however, there is no confirmed clinical report on anti-HNA-5a-related disorders. The aim of this study was to determine HNA-4a and HNA-5a gene frequencies among the Korean population.
  
  
  METHODS
  Genotyping of HNA-4a and HNA-5a genes of 110 healthy and unrelated Korean donors was performed using a polymerase chain reaction with sequence-specific primers and an allelespecific restriction enzyme analysis.
  
  
  RESULTS
  We found that the gene frequencies of HNA-4a and HNA-5a were 0.99 (107/110) and 0.96 (3/110), respectively, among the Korean population. But only the ones of the latter was significantly higher (P<0.01) than in the one of Caucasians.
  
  
  CONCLUSIONS
  The gene frequencies of HNA-4a and HNA-5a were determined. We also identified an individual who was the HNA-5a-negative homozygote for the granulocyte panel that could be used for anti-HNA-5a antibody identification.
authors.affiliation: Department of Laboratory Medicine, Inje University Sanggyep Paik Hospital1, Seoul, Korea. kshanmd@snu.ac.kr.
authors.forename: Tae Hee
authors.initials: TH
authors.lastname: Han
authors.forename: Kyou Sup
authors.initials: KS
authors.lastname: Han