[Genomic instability and male infertility]

Knowledge of the human genome has opened the genomic era. The genome instability, its causes and the possible consequences especially about fertility start to be understood. This instability can be observed on chromosome structure but also on genes. Different chromosomes rearrangements involved in infertility including translocations and Y chromosome deletions are described. The Y chromosome is a model of instability, and this instability is the source of its evolution. All those rearrangements are the results of illegitimate recombinations between homologous sequences. On genes we find punctual and dynamic mutations, polymorphisms and epigenetic abnormalities. They all are the results of ADN replication mistakes not corrected by the cellular machine. This machinery is the guardian of the genome integrity and in case of abnormality the programmed cellular death is induced. The knowledge of all these instability mechanisms is essential to appreciate the risk for the offspring after intracytoplasmic sperm injection. Indeed we go round physiological barriers without a complete understanding of the mechanisms involved. Thus, this is an important challenge for research teams but also for all assisted reproduction centers, dealing with ART. Genome is unstable - the very basis of its evolution. But this is also the cause of mistakes with pathological consequences like infertility and mental retardation.