title: Common and well-documented HLA alleles over all of Europe and within European sub-regions: A catalogue from the European Federation for Immunogenetics.
abstract: A catalogue of common and well-documented (CWD) human leukocyte antigen (HLA), previously established by the American Society for Histocompatibility and Immunogenetics (ASHI), is widely used as indicator for typing ambiguities to be resolved in tissue transplantation or for checking the universality of any HLA allele in the world. However, European population samples, which are characterized by a substantial level of genetic variation, are underrepresented in the ASHI catalogue. Therefore, the Population Genetics Working Group of the European Federation for Immunogenetics (EFI) has facilitated data collection for an European CWD catalogue.
  
  
  
  To this end, 2nd-field HLA-A, -B, -C,- DRB1,- DQA1,- DQB1 and -DPB1 data of 77 to 121 European population samples (21 571-3 966 984 individuals) from 3 large databases, HLA-net/Gene[VA], allelefrequencies.net and DKMS, were analysed.
  
  
  
  The total number of CWD alleles is similar in the EFI (N = 1048) and ASHI (N = 1031) catalogues, but the former counts less common (N = 236 vs 377) and more well-documented (N = 812 vs 654) alleles than the latter, possibly reflecting differences in sample numbers and sizes. Interestingly, approximately half of the CWD alleles reported by EFI were not reported by ASHI and vice-versa, underlining the distinct features of the two catalogues. Also, although 78 common alleles are widely distributed across Europe, some alleles are only common within specific sub-regions, showing regional variability.
  
  
  
  Although the definition of CWD alleles itself is affected by different parameters, calling for current updates of the list, the EFI CWD catalogue provides new insights into European population genetics and will be a very useful tool for tissue-typing laboratories in and beyond Europe.
authors.affiliation: Laboratory of Anthropology, Genetics and Peopling history (AGP), Department of Genetics and Evolution-Anthropology Unit, University of Geneva, Geneva, Switzerland.|Institute of Genetics and Genomics in Geneva (IGE3), University of Geneva Medical Center (CMU), Geneva, Switzerland.|Population Genetics Working Group of the European Federation for Immunogenetics (EFI), EFI Central Office, Leiden, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Sanchez-Mazas
authors.affiliation: Laboratory of Anthropology, Genetics and Peopling history (AGP), Department of Genetics and Evolution-Anthropology Unit, University of Geneva, Geneva, Switzerland.|Institute of Genetics and Genomics in Geneva (IGE3), University of Geneva Medical Center (CMU), Geneva, Switzerland.|Population Genetics Working Group of the European Federation for Immunogenetics (EFI), EFI Central Office, Leiden, The Netherlands.
authors.forename: J M
authors.initials: JM
authors.lastname: Nunes
authors.affiliation: Population Genetics Working Group of the European Federation for Immunogenetics (EFI), EFI Central Office, Leiden, The Netherlands.|Transplant Immunology Laboratory, Royal Liverpool and Broadgreen University Hospital, Liverpool, UK.
authors.forename: D
authors.initials: D
authors.lastname: Middleton
authors.affiliation: DKMS, German Bone Marrow Center, Tübingen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Sauter
authors.affiliation: Laboratory of Anthropology, Genetics and Peopling history (AGP), Department of Genetics and Evolution-Anthropology Unit, University of Geneva, Geneva, Switzerland.|Transplantation Immunology Unit and National Reference Laboratory for Histocompatibility (UIT/LNRH), Department of Genetic and Laboratory Medicine, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: S
authors.identifier: 0000-0001-6675-5287
authors.initials: S
authors.lastname: Buhler
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Liverpool, UK.
authors.forename: A
authors.initials: A
authors.lastname: McCabe
authors.affiliation: DKMS, German Bone Marrow Center, Tübingen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Hofmann
authors.affiliation: DKMS, German Bone Marrow Center, Tübingen, Germany.
authors.forename: D M
authors.initials: DM
authors.lastname: Baier
authors.affiliation: DKMS, German Bone Marrow Center, Tübingen, Germany.
authors.forename: A H
authors.initials: AH
authors.lastname: Schmidt
authors.affiliation: Swiss Transfusion Swiss Red Cross (SRC)/Swiss Blood Stem Cells, Bern, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Nicoloso
authors.affiliation: Population Genetics Working Group of the European Federation for Immunogenetics (EFI), EFI Central Office, Leiden, The Netherlands.|Laboratory of Immunogenetics and Transplant Biology, IME Foundation, Policlinic of the University of Tor Vergata, Rome, Italy.
authors.forename: M
authors.identifier: 0000-0003-3451-3624
authors.initials: M
authors.lastname: Andreani
authors.affiliation: Population Genetics Working Group of the European Federation for Immunogenetics (EFI), EFI Central Office, Leiden, The Netherlands.|Tissue Typing Center, University Hospital Center Zagreb, Zagreb, Croatia.
authors.forename: Z
authors.initials: Z
authors.lastname: Grubic
authors.affiliation: Population Genetics Working Group of the European Federation for Immunogenetics (EFI), EFI Central Office, Leiden, The Netherlands.|Transplantation Immunology Unit and National Reference Laboratory for Histocompatibility (UIT/LNRH), Department of Genetic and Laboratory Medicine, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: J-M
authors.initials: JM
authors.lastname: Tiercy
authors.affiliation: Population Genetics Working Group of the European Federation for Immunogenetics (EFI), EFI Central Office, Leiden, The Netherlands.|Institute for Experimental Cellular Therapy, University Hospital Essen, Essen, Germany.|German Cancer Consortium (DKTK), German Cancer Research Center, Heidelberg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Fleischhauer
mesh_terms: D000483:Alleles; D016208:Databases, Factual; D005060:Europe; D015870:Gene Expression; D005787:Gene Frequency; D014644:Genetic Variation; D005828:Genetics, Population; D006680:HLA Antigens / Q000145:classification / Q000235:genetics* / Q000276:immunology; D006239:Haplotypes; D006650:Histocompatibility Testing; D006801:Humans; D007125:Immunogenetics / Q000379:methods*; D009626:Terminology as Topic; D044465:White People
chemical_list: D006680:HLA Antigens
keywords: CWD catalogue; EFI; Europe; HLA alleles; population genetics; tissue typing