A male infertility due to sperm disorder characterized by the presence, in sperm, of a large majority of round-headed spermatozoa that lack the acrosome and have an aberrant nuclear membrane and midpiece defects. The acrosomeless spermatozoa is not able to penetrate the zona pellucida following intercourse or IVF thus fertilization fails. Fertilization efficiency is also very low following intracytoplasmic spem injection due to the absence of the oocyte activation factor protein PLCzeta.