Sex reversal mutations in mammals occur in:
Sex reversal in mammals can occur through mutations in multiple genes because gonadal fate depends on balanced antagonistic loops. Loss of ovary-promoting genes Wnt4, Rspo1, Foxl2 or β-catenin derepresses Sox9 leading to XX testes, while duplication or enhancer activation of Sox9 itself also causes XX sex reversal. Conversely loss of Sox9, Sf1 or Fgf9 causes XY male-to-female reversal with ovaries. Mutations affecting β-catenin stabilization produce similar phenotypes. Since testis and ovary programs mutually inhibit each other, disrupting any node can tilt balance, therefore correct answer in
Ref: Nature Reviews Genetics, Disorders of Sex Development - antagonistic pathway mutations causing sex reversal.