Mondo Description Male infertility with teratozoospermia due to single gene mutation is a rare, genetic male infertility due to sperm disorder characterized by the presence of spermatozoa with abnormal morphology, such as macrozoospermia or globozoospermia, in over 85% of sperm, resulting from mutation in a single gene known to cause teratozoospermia. It is a heterogeneous group that includes a wide range of abnormal sperm phenotypes affecting, solely or simultaneously, head, neck, midpiece, and/or tail.