摘要
Dear Editor, There are two main causes of severe asthenozoospermia： ultrastructural defects （genetically inherited and congenital defects） of the sperm flagellum and necrozoospermia or sperm degeneration secondary to other pathological changes （see review by Ortega et al2）. Genetic-related absolute asthenozoospermia includes primary ciliary dyskinesia and dysplasia of the fibrous sheath （DFS）, which result in 100% （or nearly） immotile spermatozoa.
Dear Editor, There are two main causes of severe asthenozoospermia： ultrastructural defects （genetically inherited and congenital defects） of the sperm flagellum and necrozoospermia or sperm degeneration secondary to other pathological changes （see review by Ortega et al2）. Genetic-related absolute asthenozoospermia includes primary ciliary dyskinesia and dysplasia of the fibrous sheath （DFS）, which result in 100% （or nearly） immotile spermatozoa.
