Genetic explanations

• Gender dysphoria may be caused by having an abnormal androgen receptor gene which reduces the action of testosterone
• Evidence from twin studies suggests that GD may have a genetic basis
• Gunter heylens

  Published a meta analysis of twins where at least one twin had GD. They found 39%concordance of the MZ (identical twins)

  Suggests there may be a genetic element
• Twin studies assume that identical twins are treated equally similarly and that only genetic factors account for the ways DZ twins are less alike than MZ twins

  MZ twins have very similar experiences - brought up the same way so might not be entirely genetic
• GD is so rare and the sample sizes are small which means that it cannot be generalised