title: Sex differences in the genetic basis of morning serum cortisol levels: genome-wide screen identifies two novel loci specific to women.
abstract: BACKGROUND
  Relatively little is known about the influence of specific genes on cortisol levels, particularly morning cortisol levels.
  
  
  OBJECTIVE
  The objective of this study was to identify quantitative trait loci associated with morning serum cortisol levels.
  
  
  METHODS
  We carried out a genome screen for morning serum cortisol using linkage and association methods tailored for use in large pedigrees. We conducted these analyses both in the whole sample and partitioned by sex.
  
  
  METHODS
  This study was conducted on nine communal Hutterite farms in South Dakota.
  
  
  METHODS
  The Hutterites are a young founder population who practice a communal, farming lifestyle in the western United States and in Canada. Hutterites (n = 504, 53% female) aged 11-89 yr from a single pedigree participated in this study.
  
  
  METHODS
  The main outcome measures were markers significantly linked or associated with variation in morning serum cortisol levels.
  
  
  RESULTS
  One genome-wide significant association was identified in the whole sample on 11p (D11S1981, P = 0.000092). Results of sex-partitioned analyses indicated that this association was restricted to females (females, P = 0.000084; males, P = 0.20). The 146-bp allele at this locus accounted for 7% of the variance in morning cortisol values in females, and females homozygous for the allele had an 89% increase in morning cortisol levels compared with female noncarriers. A second genome-wide significant association in females was identified on 14q (D14S74, P = 0.000091).
  
  
  CONCLUSIONS
  Our results suggest that the genetic determinants of morning cortisol levels may be different for men and women and that loci on 11p and 14q influence morning cortisol levels in women.
authors.affiliation: Department of Health Studies, The University of Chicago, 5841 South Maryland Avenue, MC2007, Chicago, Illinois 60637, USA. lkurina@uchicago.edu
authors.forename: Lianne M
authors.initials: LM
authors.lastname: Kurina
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Weiss
authors.forename: Steven W
authors.initials: SW
authors.lastname: Graves
authors.forename: Rodney
authors.initials: R
authors.lastname: Parry
authors.forename: Gordon H
authors.initials: GH
authors.lastname: Williams
authors.forename: Mark
authors.initials: M
authors.lastname: Abney
authors.forename: Carole
authors.initials: C
authors.lastname: Ober
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002880:Chromosomes, Human, Pair 11; D002883:Chromosomes, Human, Pair 14; D005260:Female; D018703:Founder Effect; D008040:Genetic Linkage; D005820:Genetic Testing; D015894:Genome, Human; D006801:Humans; D006854:Hydrocortisone / Q000097:blood* / Q000235:genetics*; D008297:Male; D012727:Sex Characteristics; D013023:South Dakota
chemical_list: D006854:Hydrocortisone