[Screening for Y chromosome microdeletions in assisted reproductive techniques]

In case of infertility due to azoospermia, clinical, sonographical and biological examinations suggest obstructive or non obstructive causes. In cases of non obstructive azoospermia, genomic microdeletions must be determined particularly in the Y chromosome long arm, as well as autosomal abnormality. A constitutional karyotype must also be done. The so-called Y AZFa, AZFb and AZFc zones could be partially or totally absent. Genotype is mostly correlated with histology. Thus, when large AZFa and AZFb microdeletions are detected there is theoretically no chance to find testicular spermatozoa. If only AZFc microdeletions are present, testicular biopsy is possible with a good chance of mature spermatozoa retrieval before microinjection, and AZFc microdeletions are also often present (10%) in cases of severe oligospermia. Couples must be informed of genomic deletions and a genetic counseling is essential to explain the potential childhood risks after assisted reproductive techniques. This problem has been discussed by the French "High Authority of Health". It recommends determination of these Y microdeletions when oligozoospermia is severe (lower than one million spermatozoa per milliliter).