SYCE1 (synaptonemal complex central element protein 1) is a major structural component of the transverse central element of synaptonemal complexes (SCs), which form between homologous chr10 during meiotic prophase 1. The protein adopts a curved coiled-coil structure approximately 50 nm in length, functioning as a physical strut that stabilizes the SC central element 1. SYCE1 requires interaction with SYCP1 for incorporation into the central element and is essential for homologous chromosome 10 and meiotic recombination 2. Pathogenic SYCE1 mutations cause primary ovarian insufficiency (POI) and non-obstructive azoospermia (NOA), two major causes of human infertility 34. Identified mutations include homozygous deletions (c.689_690del) and splice site mutations (c.197-2A>G) that disrupt SYCE1 expression, protein localization, or binding to interaction partners 56. In mouse models, the c.197-2A>G mutation causes transcript degradation, impaired homologous chromosome 10, meiotic arrest, and increased apoptosis of meiotic cells, resulting in complete infertility in both males and females 6. Functional studies demonstrate that pathogenic SYCE1 variants disrupt SC assembly and meiotic recombination 2. Whole-exome sequencing has identified SYCE1 mutations in approximately 20-25% of POI cases and in patients with maturation arrest, establishing genetic screening as a clinically relevant diagnostic approach 37.