Novel PLCZ1 mutation caused polyspermy during in vitro fertilization

Asian J Androl. 2024 Mar 5. doi: 10.4103/aja202376. Online ahead of print.ABSTRACTFailure of oocyte activation, including polyspermy and defects in pronuclear (PN) formation, triggers early embryonic developmental arrest. Many studies have shown that phospholipase C zeta 1 (PLCZ1) mutations cause failure of PN formation following intracytoplasmic sperm injection (ICSI); however, whether PLCZ1 mutation is associated with polyspermy during in vitro fertilization (IVF) remains unknown. Whole-exome sequencing (WES) was performed to identify candidate mutations in couples with primary infertility. Sanger sequencing was used to validate the mutations. Multiple PLCZ1-mutated sperm were injected into human and mouse oocytes to explore whether PN formation was induced. Assisted oocyte activation (AOA) after ICSI was performed to overcome the failure of oocyte activation. We identified three PLCZ1 mutations in three patients who experienced polyspermy during IVF cycles, including a novel missense mutation c.1154C>T, p.R385Q. PN formation failure was observed during the ICSI cycle. However, injection of multiple PLCZ1-mutated sperm induced PN formation, suggesting that the Ca2+ oscillations induced by the sperm exceeded the necessary threshold for PN formation. AOA after ICSI enabled normal fertilization, and all patients achieved successful pregnancies. These findings expand the mutational spectrum of PLCZ1 and suggest an important role for PLCZ1 in terms of blocking polyspermy. Fur...
Source: Asian Journal of Andrology - Category: Urology & Nephrology Authors: Source Type: research