Phenotypic varieties of sperm pathology: Genetic abnormalities or environmental influences can result in different patterns of abnormal spermatozoa.

The present paper reviews in detail ultrastructural and molecular studies addressed to characterize different phenotypes of sperm pathology in sterile men. In each case ultrastructural, immunocytochemical, molecular and genetic information is provided to differentiate two main kinds of sperm pathologies: systematic phenotypes with known or suspected genetic origin and non-systematic ones, usually secondary to different pathologies of the male reproductive system. Special attention is paid to detailed ultrastructural features profusely illustrated with electron micrographs. Diagnostic and fertility prognostic values of these phenotypes are also discussed and, when possible, comparison with similar pathologies in mammals and birds are discussed.