Practice question

XX male syndrome occurs frequently due to aberrant recombination during paternal meiosis where SRY-containing segment of short arm Y translocates onto distal Xp or autosome. Offspring inheriting recombined chromosome are karyotypically XX but carry functional SRY capable of initiating Sox9 activation and testis determination despite absence of other Y genes such as AZF needed for spermatogenesis. Individuals develop phenotypic males with testes, male internal ducts and external genitalia though typically azoospermic and sterile. Incidence around 1 in 20,000 males reveals sufficiency of SRY for gonadal male development.