title: Low occurrence of the HLA-C*04:09N allele in a large Hungarian cohort.
abstract: The presence of null alleles may affect the outcome of stem cell transplantation. HLA-C*04:09N was defined as 'common' with a frequency of 2-5/1000 in Caucasians, and its presence is routinely tested as part of haplotypes HLA-A*02:01/A*23:01-B*44:03-DRB1*07:01-DQB1*02:01. We aimed to investigate HLA-C*04:09N in a representative Hungarian cohort. HLA-typing data of 7345 unrelated persons were analyzed. The presence of HLA-C*04:09N was excluded in 157 chromosomes with either serology typing or with an allele-specific polymerase chain reaction for HLA-C*04:09N. HLA-C*04:09N was identified in a single chromosome with HLA-A*02, B*44, C*04, DRB1*07 resulting in a HLA-C*04:09N allele frequency of 0.0068% (1/14,690). This is approximately a 10- to 40-fold lower frequency compared with the previous data. Our results emphasize the need of precise local population-specific HLA-data, allowing appropriate modifications of local HLA-typing protocols.
authors.affiliation: Laboratory of Molecular Diagnostics, Hungarian National Blood Transfusion Service, Budapest, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Bors
authors.affiliation: Laboratory of Transplantation Immunogenetics, Hungarian National Blood Transfusion Service, Budapest, Hungary.
authors.forename: D
authors.initials: D
authors.lastname: Inotai
authors.affiliation: Laboratory of Molecular Diagnostics, Hungarian National Blood Transfusion Service, Budapest, Hungary.
authors.forename: H
authors.initials: H
authors.lastname: Andrikovics
authors.affiliation: Laboratory of Transplantation Immunogenetics, Hungarian National Blood Transfusion Service, Budapest, Hungary.
authors.forename: S
authors.initials: S
authors.lastname: Benkő
authors.affiliation: Laboratory of Transplantation Immunogenetics, Hungarian National Blood Transfusion Service, Budapest, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Boros-Major
authors.affiliation: Laboratory of Transplantation Immunogenetics, Hungarian National Blood Transfusion Service, Budapest, Hungary.
authors.forename: Z
authors.initials: Z
authors.lastname: Illés
authors.affiliation: Laboratory of Transplantation Immunogenetics, Hungarian National Blood Transfusion Service, Budapest, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Szilvási
authors.affiliation: Bone Marrow Donor Registry, Hungarian National Blood Transfusion Service, Budapest, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Gelle-Hossó
authors.affiliation: Bone Marrow Donor Registry, Hungarian National Blood Transfusion Service, Budapest, Hungary.
authors.forename: K
authors.initials: K
authors.lastname: Rajczy
authors.affiliation: Laboratory of Molecular Diagnostics, Hungarian National Blood Transfusion Service, Budapest, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Tordai
mesh_terms: D000483:Alleles; D016026:Bone Marrow Transplantation; D015870:Gene Expression; D005787:Gene Frequency; D015236:HLA-C Antigens / Q000235:genetics* / Q000276:immunology; D006239:Haplotypes; D006650:Histocompatibility Testing; D006801:Humans; D006814:Hungary; D014019:Tissue Donors; D066027:Transplant Recipients
chemical_list: D015236:HLA-C Antigens; C495437:HLA-C*04:09N antigen
keywords: HLA-C*04:09N; HLA-typing; Hungarian population; common haplotype; null-allele