LRRC46 (leucine-rich repeat containing 46) is a structural protein with dual roles in reproductive and ocular development. Primarily, LRRC46 is essential for spermatogenesis and male fertility, localizing to the sperm flagellar midpiece and playing a critical role in sperm flagellum biogenesis 1. Loss of LRRC46 function in mice produces multiple morphological abnormalities of sperm flagella (MMAF), resulting in short, coiled, and irregular flagella alongside reduced sperm motility and complete male infertility 1. At the cellular level, LRRC46 is required for proper axonemal and mitochondrial sheath formation within flagella 1. Beyond reproduction, LRRC46 functions in ocular tissue maintenance. The protein is expressed in corneal and scleral tissues, where it regulates collagen synthesis, particularly collagen VIII (Col8a1) 2. LRRC46 deficiency in mice causes corneal and scleral thinning, reduced limbal stem cell activity, and decreased extracellular matrix gene expression, leading to classical myopia phenotypes 2. Clinically, LRRC46 mutations associate with male infertility via MMAF pathogenesis 1. Additionally, LRRC46 has been identified as a candidate gene in cancer contexts, showing altered expression in nasopharyngeal carcinoma and hepatocellular carcinoma, and associated with high-grade serous ovarian cancer susceptibility 3, 4, 5. Its role in cilia-associated gene networks also links LRRC46 to reproductive tract physiology relevant to ectopic pregnancy detection 6.