The inability of the male to effect fertilization of an ovum after a specified period of unprotected intercourse. Male sterility is permanent infertility.

Spermatogenic failure-6 (SPGF6) is a form of male infertility with globozoospermia. The acrosome is a unique structure of the mature spermatozoon, which plays an important role at the site of sperm-zonapellucida binding during the fertilization process. Globozoospermia (also called round-headed spermatozoa) is a human infertility syndrome caused by spermatogenesis defects (Lalonde et al., 1988, Singh, 1992). The most prominent feature of globozoospermia is the malformation of the acrosome and, in the most severe cases, the acrosome is totally absent. Globozoospermia is also characterized by abnormal nuclear shape as well as abnormal arrangement of the mitochondria of the spermatozoon (Battaglia et al., 1997). For a discussion of phenotypic and genetic heterogeneity of spermatogenic failure, see SPGF1 (258150).

Spermatozoa with multiple flagella attached to the sperm head.

An abnormal reduction in the mobility of ejaculated sperm.

Excess residual cytoplasm is associated with abnormal spermatozoa produced from a defective spermiation process. This abnormal excess cytoplasm should not be confused with more physiological cytoplasmic residues that can be observed in direct microscopy of the ejaculate but not in dried, fixed and stained morphology smears.