Total fertilization failure (TFF), which is the failure of fertilization in all oocytes, occurs in 1%-3% of intracytoplasmic sperm injection (ICSI) cycles. However, the sperm-related factors that cause fertilization failure in humans are still largely unknown. Here, we identified three novel homozygous variations in the PLCZ1 gene in a recessive inheritance pattern in three consanguineous families, which all located in a key catalytic domain, and predicted to modify its secondary structure and thus impair its hydrolytic activity. Moreover, immunofluorescent staining revealed that PLCζ in mutant sperm exhibited abnormal localization patterns. ICSI-AOA resulted in an increased rate of normal fertilization compared with previous ICSI cycles (75.0% vs 2.2%, P < .001). In summary, we identified three novel homozygous variations in PLCZ1 that led to poor or failed fertilization that could be overcame by ICSI-AOA.
Keywords: Phophospholipase C zeta; assisted oocyte activation; fertilization failure; variation.
© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.