Infertilité liée à la qualité du génome spermatique et impact en Procréation Médicalement Assistée.

Abstract

Male infertility is a relatively common pathology; the genetic etiology may be a cause of this abnormality for these males presumed sterile. Thanks to new techniques of Medically Assisted Procreation that infertile men could become biological fathers. However, some questions about the genetic and epigenetic information transmitted to the offspring as well as the modalities of this transmission are raised. A genetic study was carried out over 101 infertile male patients candidates for the Medically Assisted Procreation, these subjects are registered with their spouses in a schedule of intra-cytoplasmic microinjection of the spermatozoon. This study was performed in a prospective setting using cytogenetic tools. Two approaches have been tried in order to assess the quality of the sperm genome. One by analyzing the quality of sperm DNA by measuring the rate of degradation and fragmentation of the latter, another by exploring the quality of spermatic chromatin by measuring its decondensation rate. The study of the association between the quality of the spermatic genome and the various classical spermiological factors shows that the alteration of spermatogenesis is related to a deterioration of the spermatic genome. Regarding the behavioral, toxic and environmental factors, our study showed that these factors did not act on the quality of the spermatic genome. Nevertheless, smoking intoxication seems to alter the chromatin structure of a specific category of patients (p = 0.03). The evaluation of the various parameters was related to the status of Medically Assisted Reproduction especially those of microinjection into cytoplasmic sperm. Our results showed that alterations in the quality of the spermatic genome do not influence either the fertilization process or preimplantation embryonic development (p > 0.05). Our findings indicate also that the quality of the spermatic genome is not related to pregnancy. Nonetheless, it may have an impact on abortions. Regarding births, the integrity of the spermatic nucleus may influence the birth rate (p = 0.064). Moreover, a differentiated sperm cell with an unaltered DNA can give birth even if its chromatin is poorly structured or even decondensed.