From OMIMAbout 2 to 3% of human males are infertile because of defects in sperm function, primarily due to oligozoospermia (defined as less than 10-15 million sperm per mL of semen) or azoospermia (Hull et al., 1985).
Heterogeneity of Spermatogenic Failure
For a discussion of Y-linked spermatogenic failure due to Sertoli cell-only syndrome, see 400042.
For a discussion of phenotypic and genetic heterogeneity of spermatogenic failure, see SPGF1 (258150).
http://www.omim.org/entry/415000 From MedlinePlus GeneticsY chromosome infertility is a condition that affects the production of sperm and causes male infertility, which means it is difficult or impossible for affected men to father children. An affected man's body may produce no mature sperm cells (azoospermia), fewer than the usual number of sperm cells (oligospermia), or sperm cells that are abnormally shaped or that do not move properly. Men with Y chromosome infertility do not have any other signs or symptoms related to the condition.
Some men with Y chromosome infertility who have mild to moderate oligospermia may eventually father a child naturally. Men with oligospermia may also be helped with assisted reproductive technologies; most men with Y chromosome infertility have some sperm cells in the testes that can be extracted for this purpose.
https://medlineplus.gov/genetics/condition/y-chromosome-infertility