title: Common Polymorphisms at the CYP17A1 Locus Associate With Steroid Phenotype: Support for Blood Pressure Genome-Wide Association Study Signals at This Locus.
abstract: Genome-wide association studies implicate the CYP17A1 gene in human blood pressure regulation although the causative polymorphisms are as yet unknown. We sought to identify common polymorphisms likely to explain this association. We sequenced the CYP17A1 locus in 60 normotensive individuals and observed 24 previously identified single-nucleotide polymorphisms with minor allele frequency >0.05. From these, we selected, for further studies, 7 polymorphisms located ≤ 2 kb upstream of the CYP17A1 transcription start site. In vitro reporter gene assays identified 3 of these (rs138009835, rs2150927, and rs2486758) as having significant functional effects. We then analyzed the association between the 7 polymorphisms and the urinary steroid metabolites in a hypertensive cohort (n=232). Significant associations included that of rs138009835 with aldosterone metabolite excretion; rs2150927 associated with the ratio of tetrahydrodeoxycorticosterone to tetrahydrodeoxycortisol, which we used as an index of 17α-hydroxylation. Linkage analysis showed rs138009835 to be the only 1 of the 7 polymorphisms in strong linkage disequilibrium with the blood pressure-associated polymorphisms identified in the previous studies. In conclusion, we have identified, characterized, and investigated common polymorphisms at the CYP17A1 locus that have functional effects on gene transcription in vitro and associate with corticosteroid phenotype in vivo. Of these, rs138009835--which we associate with changes in aldosterone level--is in strong linkage disequilibrium with polymorphisms linked by genome-wide association studies to blood pressure regulation. This finding clearly has implications for the development of high blood pressure in a large proportion of the population and justifies further investigation of rs138009835 and its effects.
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Louise A
authors.initials: LA
authors.lastname: Diver
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Scott M
authors.initials: SM
authors.lastname: MacKenzie
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Robert
authors.initials: R
authors.lastname: Fraser
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Frances
authors.initials: F
authors.lastname: McManus
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: E Marie
authors.initials: EM
authors.lastname: Freel
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Samantha
authors.initials: S
authors.lastname: Alvarez-Madrazo
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: John D
authors.initials: JD
authors.lastname: McClure
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Elaine C
authors.initials: EC
authors.lastname: Friel
authors.affiliation: Centre for Endocrinology & Diabetes, Institute of Human Development, Faculty of Medical & Human Sciences, University of Manchester, Manchester, United Kingdom.
authors.forename: Neil A
authors.initials: NA
authors.lastname: Hanley
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Anna F
authors.initials: AF
authors.lastname: Dominiczak
authors.affiliation: William Harvey Research Institute and the Barts National Institute for Health Research Biomedical Research Unit, Queen Mary University of London, London, United Kingdom.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Caulfield
authors.affiliation: William Harvey Research Institute and the Barts National Institute for Health Research Biomedical Research Unit, Queen Mary University of London, London, United Kingdom.
authors.forename: Patricia B
authors.initials: PB
authors.lastname: Munroe
authors.affiliation: Medical Research Institute, College of Medicine, Dentistry, and Nursing, University of Dundee, Dundee, United Kingdom.
authors.forename: John M
authors.initials: JM
authors.lastname: Connell
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Eleanor
authors.initials: E
authors.lastname: Davies
mesh_terms: D000328:Adult; D000368:Aged; D000450:Aldosterone / Q000378:metabolism; D000483:Alleles; D001794:Blood Pressure / Q000235:genetics; D015331:Cohort Studies; D005260:Female; D005786:Gene Expression Regulation; D055106:Genome-Wide Association Study; D064368:Healthy Volunteers; D006801:Humans; D006973:Hypertension / Q000235:genetics*; D019901:Locus Control Region / Q000235:genetics; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012016:Reference Values; D013252:Steroid 11-beta-Hydroxylase / Q000235:genetics*; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics*
chemical_list: D000450:Aldosterone; C501892:CYP17A1 protein, human; D013254:Steroid 17-alpha-Hydroxylase; D013252:Steroid 11-beta-Hydroxylase
keywords: aldosterone; blood pressure; genome-wide association study; hypertension; polymorphism, single nucleotide