Despite successful formation of double-strand breaks (DSBs) [6], the initiating event in meiotic recombination, knockout of Prdm9 results in infertility in both male and female mice with arrest of spermatogenesis and oogenesis at pachynema, impairment of DSB repair, chromosome asynapsis, and disrupted sex-body formation in males [12]. The gene discussed is PRDM9; the disease is Infertility.