Necrospermia or immotile cilia syndrome as a cause of male infertility.

A case of infertility secondary to necrospermia was reinvestigated and reclassified as the "immotile cilia syndrome". The immotile spermatozoa were viable but motionless owing to an ultrastructural defect of the tail characterized by absence of microtubular dynein sidearms. There is no therapy for this congenital disorder and artificial insemination was performed.