DNA fragmentation and meiotic segregation in sperm of carriers of a chromosomal structural abnormality

Objective To determine the meiotic segregation and DNA fragmentation in spermatozoa of carriers of a chromosomal structural abnormality. Design Case series. Setting University hospital. Patient(s) Thirty-seven male carriers of a chromosomal structural abnormality (21 with a balanced reciprocal translocation, 7 with a robertsonian translocation, 9 with a pericentric inversion). Intervention(s) Meiotic segregation was analyzed by the human sperm–hamster oocyte fusion technique or by fluorescent in situ hybridization, and DNA fragmentation was detected by terminal deoxynucleotidyl transferase–mediated dUTP nick-end labeling assay. Main Outcome Measure(s) Relationships between abnormal sperm parameters, DNA fragmentation, and meiotic mechanisms. Result(s) The average rates of chromosomally unbalanced spermatozoa were 55.22%, 14.09%, and 18.43% for reciprocal translocation, robertsonian translocation, and pericentric inversion carriers, respectively. The rates of DNA fragmentation were significantly higher in the whole group of carriers of a chromosomal structural abnormality and in each specific group than in the control group. No correlations between sperm DNA fragmentation and parameters of spermogram, age, or percentage of unbalanced chromosomal gametes were found. Conclusion(s) The DNA fragmentation rate depends solely on the presence of a chromosomal structural abnormality, and, therefore, a chromosomal structural abnormality predicts DNA fragmentation. Both meiotic segregation and DNA fragmentation studies should be integrated in the genetic exploration of male carriers of a chromosomal structural abnormality.