title: Positive selection in the chromosome 16 VKORC1 genomic region has contributed to the variability of anticoagulant response in humans.
abstract: VKORC1 (vitamin K epoxide reductase complex subunit 1, 16p11.2) is the main genetic determinant of human response to oral anticoagulants of antivitamin K type (AVK). This gene was recently suggested to be a putative target of positive selection in East Asian populations. In this study, we genotyped the HGDP-CEPH Panel for six VKORC1 SNPs and downloaded chromosome 16 genotypes from the HGDP-CEPH database in order to characterize the geographic distribution of footprints of positive selection within and around this locus. A unique VKORC1 haplotype carrying the promoter mutation associated with AVK sensitivity showed especially high frequencies in all the 17 HGDP-CEPH East Asian population samples. VKORC1 and 24 neighboring genes were found to lie in a 505 kb region of strong linkage disequilibrium in these populations. Patterns of allele frequency differentiation and haplotype structure suggest that this genomic region has been submitted to a near complete selective sweep in all East Asian populations and only in this geographic area. The most extreme scores of the different selection tests are found within a smaller 45 kb region that contains VKORC1 and three other genes (BCKDK, MYST1 (KAT8), and PRSS8) with different functions. Because of the strong linkage disequilibrium, it is not possible to determine if VKORC1 or one of the three other genes is the target of this strong positive selection that could explain present-day differences among human populations in AVK dose requirement. Our results show that the extended region surrounding a presumable single target of positive selection should be analyzed for genetic variation in a wide range of genetically diverse populations in order to account for other neighboring and confounding selective events and the hitchhiking effect.
authors.affiliation: Inserm UMRS-946, Genetic Variability and Human Diseases, Institut Universitaire d'Hématologie, Université Paris Diderot, Paris, France. blandine.patillon@inserm.fr
authors.forename: Blandine
authors.initials: B
authors.lastname: Patillon
authors.forename: Pierre
authors.initials: P
authors.lastname: Luisi
authors.forename: Hélène
authors.initials: H
authors.lastname: Blanché
authors.forename: Etienne
authors.initials: E
authors.lastname: Patin
authors.forename: Howard M
authors.initials: HM
authors.lastname: Cann
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Génin
authors.forename: Audrey
authors.initials: A
authors.lastname: Sabbagh
mesh_terms: D015110:4-Hydroxycoumarins / Q000008:administration & dosage / Q000627:therapeutic use; D000925:Anticoagulants / Q000008:administration & dosage* / Q000627:therapeutic use; D054316:Biomarkers, Pharmacological / Q000378:metabolism; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance / Q000235:genetics*; D005260:Female; D014644:Genetic Variation / Q000502:physiology; D005843:Geography; D006239:Haplotypes; D006801:Humans; D007192:Indenes / Q000008:administration & dosage / Q000627:therapeutic use; D007206:Individuality; D015810:Linkage Disequilibrium; D008297:Male; D006899:Mixed Function Oxygenases / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000502:physiology; D012641:Selection, Genetic / Q000502:physiology*; D014812:Vitamin K / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000627:therapeutic use; D064417:Vitamin K Epoxide Reductases
chemical_list: D015110:4-Hydroxycoumarins; D000925:Anticoagulants; D054316:Biomarkers, Pharmacological; D007192:Indenes; C011664:antivitamins K; D014812:Vitamin K; D006899:Mixed Function Oxygenases; C578523:VKORC1 protein, human; D064417:Vitamin K Epoxide Reductases