Integrating Early Genetic Screening with Artificial Oocyte Activation: A Precision Reproductive Medicine Approach for PLCZ1-Related Infertility

Oocyte activation deficiency (OAD) due to PLCZ1 variants is a well-established cause of total fertilization failure (TFF) in intracytoplasmic sperm injection (ICSI). However, the full spectrum of pathogenic variants and the safety of artificial oocyte activation (AOA) as a rescue strategy remain incompletely characterized. Here, we integrated clinical, genetic, and functional approaches to investigate four unrelated infertile families with recurrent TFF. Whole-exome sequencing identified six pathogenic PLCZ1 variants-including a novel frameshift variant (c.865-3_869del/p.A289Kfs∗7) and three novel missense variants (c.1049C>T/p.S350F, c.1136T>C/p.I379T, c.1538T>C/p.F513S)-segregating in biallelic compound heterozygous patterns. In silico modeling revealed disruption of critical domains, while sperm analyses demonstrated PLCζ protein deficiency and severely impaired enzyme activity. Integrated sperm transcriptomic and proteomic profiling further indicated dysregulation of calcium signaling and gamete interaction pathways. Following AOA with A23187, fertilization rates improved dramatically, yielding euploid blastocysts and two healthy live births. Comprehensive genomic assessment of offspring confirmed normal karyotypes and absence of pathogenic copy number variations. Our findings expand the mutational landscape of PLCZ1-related OAD and provide robust evidence that early genetic diagnosis coupled with AOA represents a safe and effective precision therapy for this form of male infertility.