research Evaluation of the Predictive Capacity of DNA Variants Associated with Straight Hair in Europeans 36 citations, September 2015 in “Forensic Science International: Genetics” Certain DNA variants can predict straight hair in Europeans but are not highly specific.
research Common Variants in the Trichohyalin Gene Are Associated with Straight Hair in Europeans 234 citations, November 2009 in “American journal of human genetics” Common variants in the Trichohyalin gene are linked to straight hair in Europeans.