Microdeletions of Y Chromosome

Microdeletions of Y Chromosome

The causes of infertility in humans can often have a genetic basis. Among the genetic causes that lead lower sperm quality, the microdeletions of Y chromosome are often present. Y chromosome is one of the two sex chromosomes and is what differentiates the male from the female individual.

Microdeletions of Y chromosome are related with male infertility and are associated with chromosomal regions containing genes responsible for spermatogenesis. These genetic regions are AZFa, AZFb and AZFc (Azoospermia Factor). The lack of these three genetic regions results in azospermia of different severity, according to the missing genes. The most serious case is the lack of AZFa, which leads to complete absence of sperm. Second in severity is the lack of AZFb which can cause moderate to severe oligospermia, while less severe oligospermia can be caused by a lack of AZFc (<5ml spermatozoa / ml).
The examination for Y chromosome microdeletions is usually suggested in men with azoospermia or oligospermia, teratospermia or asthenospermia, when other possible causes of infertility have been excluded.

What is suggested if microdeletion of Y chromosome are diagnosed?
The type of microdeletions that will be identified also crucial for choosing the most appropriate treatment. Testicular biopsy for sperm retrieval is considered an effective solution for cases of AZFc deficiencies, but unsuitable for men with AZFb or AZFα deficiencies.

Often, patients diagnosed with Y chromosome microdeletions or oligospermic patients are advised to freeze sperm sample, as over the years its quality may decline even more. Therefore, cryopreservation of the sperm sample in time may be important for the outcome of a potential assisted reproductive cycle.

Is there a risk for my children’s health, if I am diagnosed with chromosome Y microdeletions?

The couple should be aware, before an IVF cycle, that if the potential father bears microdeletions of the Y chromosome, then they will be inherited to all his male children.