Spermatogenic failure-16 (SPGF16) is characterized by acephalic spermatozoa causing male infertility. Semen from affected men consistently shows nearly 100% abnormally shaped spermatozoa, mostly made up of headless tails, with a small proportion of intact spermatozoa with an abnormal head-tail junction, as well as a few tailless heads. Ultrastructurally, the anomaly involves absence of the implantation fossa and basal plate between the sperm head and the tail (summary by Zhu et al., 2016).
For a discussion of genetic heterogeneity of spermatogenic failure, see SPGF1 (258150). [from
OMIM]