Common variants in the Trichohyalin gene are associated with straight hair in Europeans

  • Dr Sarah Medland, Queensland Institute of Medical Research, Brisbane, Australia, Australia
  • Dr Dale Nyholt, Queensland Institute of Medical Research, Brisbane, Australia, Australia
  • Dr Jodie Painter, Queensland Institute of Medical Research, Brisbane, Australia, Australia
  • Dr Brian McEvoy, Queensland Institute of Medical Research, Brisbane, Australia, Australia
  • Dr Allan McRae, Queensland Institute of Medical Research, Brisbane, Australia, Australia
  • QIMR GWAS Consortium, Queensland Institute of Medical Research, Brisbane, Australia, Australia
  • Prof Grant Montgomery, Queensland Institute of Medical Research, Brisbane, Australia, Australia
  • Prof Nicholas Martin, Queensland Institute of Medical Research, Brisbane, Australia, Australia

Hair morphology is highly differentiated between populations and among people of European ancestry. While hair morphology in East Asian populations has been studied extensively, relatively little is known about the genetics of this trait in Europeans. We performed a genome-wide association scan for hair morphology (straight, wavy, curly) in three Australian samples of European descent. All three samples showed evidence of association implicating the Trichohyalin gene (TCHH), expressed in the developing inner root sheath of the hair follicle, and explaining ~6% of variance (P=1.5x10-31). These variants are at their highest frequency in Northern Europeans, paralleling the distribution of the straight haired EDAR variant in Asian populations.