Two cases of sperm immotility: a mosaic of flagellar alterations related to dysplasia of the fibrous sheath and abnormalities of head-neck attachment.

Objective: To characterize the association of two systematic sperm defects.

Design: Case report.

Setting: University, Interdepartmental Centre for Research and Therapy of Male Infertility.

Patient(s): Patient 1, 42 years old, and patient 2, 38 years old, both with severe asthenozoospermia.

Intervention(s): Family history, physical examination, hormonal analysis, microbial assays, semen analysis, transmission and scanning electron microscopy, immunocytochemistry for tubulin, and fluorescence in situ hybridization (FISH) for chromosomes 18, X, and Y.

Main Outcome Measure(s): Admixture of dysplasia of the fibrous sheath (DFS) and head-tail misalignment up to acephalic sperm detected by microscopic methods.

Result(s): In both patients, DFS was present in incomplete form and was associated with acephalic sperm and abnormal head-tail attachment. In patient 2, spermatozoa were also affected by necrosis that may cause fragmentation leading to short flagella; submicroscopic examination allowed defining only the origin of these "stumpy" tails. Immunofluorescence confirmed the sperm alterations. FISH revealed an altered frequency of diploidy and disomy in patient 2 and a slight increase in diploidy in patient 1.

Conclusion(s): The importance of ultrastructural sperm evaluation for correct identification of sperm pathologies is evident, particularly regarding assisted reproduction technology and genetic risk assessment.