SHOC1 (shortage in chiasmata 1) is an essential meiotic ATPase that plays a critical role in crossover formation during homologous recombination. SHOC1 preferentially binds single-stranded DNA and branched DNA structures, exhibiting ATPase activity that is stimulated by single-stranded DNA, though it lacks nuclease activity in vitro 1. The protein belongs to the XPF/MUS81 endonuclease family and contains a conserved ERCC4-(HhH)2 core structure 12. During meiotic prophase I, SHOC1 functions as part of the ZMM protein complex, recruiting TEX11 and other proteins to facilitate class I crossover formation 1. SHOC1 is required for proper synaptonemal complex assembly and homologous chromosome 9, with deficiency leading to reduced MLH1 localization and abnormal synapsis 1. Bi-allelic loss-of-function variants in SHOC1 cause non-obstructive azoospermia with meiotic arrest at the zygotene stage in males 34 and premature ovarian insufficiency in females 5. These findings establish SHOC1 as a clinically relevant gene for reproductive disorders, with potential diagnostic implications for infertility management 6.