Male Factor Infertility

Statistically, 10-15% of couples experience difficulty in conceiving, with male related factors e.g. low sperm count, thought to be an underlying issue in approximately 50% of cases. Although in the majority of incidences the causes of male infertility are unknown, studies have shown that sex chromosome aneuploidy and microdeletions of specific regions of the Y-chromosome can play a role.

Klinefelter syndrome is the most common sex chromosome aneuploidy associated with male infertility. This syndrome has a live birth incidence of between 1:500 and 1:650 males with the most common cause being an additional copy of the X chromosome (47,XXY karyotype).

Y-chromosome microdeletions are the next most common genetic cause of male infertility, with microdeletions occurring in three regions (AZFa, AZFb, AZFc) detected in up to 7% of oligospermia (also known as oligozoospermia, or low sperm count) and 13% of nonobstructive azoospermia (zero sperm count) cases. These microdeletions occur due to homologous recombination of repetitive sequences in these regions and the exact molecular mechanisms and recombination events underlying these changes have been elucidated. These regions are located at chromosome Yq11 and although the AZFa microdeletion region is distinct, there is a significant degree of overlap between the regions affected by AZFb and AZFc microdeletion.

The European Academy of Andrology (EAA) and European Molecular Genetics Quality Network (EMQN) have published a series of best practice guidelines for Y-chromosome microdeletion testing characterisation and sizing of detected AZF region microdeletions using a separate defined set of markers.

The Yourgene®​ Male Factor Infertility Base​ assay is easy to set up and involves minimal hands-on time. DNA extracted from whole blood is amplified using QF-PCR and analysed quantitatively on a capillary electrophoresis genetic analyser. Results review and interpretation is simple with no data transfer required.