GLOSSARY

Y-chromosome microdeletions (YCM)

Y-chromosome microdeletions (YCM) is a family of genetic disorders caused by missing genes in the Y-chromosome, and are common in infertile men. This condition directly affects sperm production and can lead to conditions such as oligospermia, azoospermia, and teratospermia.

What is Y-chromosome microdeletion (YCM)?

Y-chromosome microdeletion (YCM) is a family of genetic disorders in the Y-chromosome. This condition has a direct impact on fertility, significantly reducing the chances of conceiving.
In many cases where patients experience reduced sperm count, forms of Y-chromosome microdeletion have been detected. This condition can lead to oligospermia, low sperm count, or azoospermia, which is defined by the absence of sperm in semen. The microdeletions that characterize this condition can be detected in three regions on the long arm of the Y-chromosome, also known as the “azoospermic factor” (AZF).

Y-chromosome microdeletion (YCM) in male fertility

Y-chromosome microdeletions are associated with severe defects in spermatogenesis and infertility. This condition is triggered by spontaneous mutations in the Y chromosome and can lead to a variety of sperm-related conditions, including oligospermia, azoospermia, or asthenospermia.
While patients suffering from Y-chromosome microdeletions can live normal lives, they are commonly infertile. However, these patients can still turn to assisted reproductive technology (ART) procedures to conceive biological children. Alternatively, if those with Y -chromosome microdeletions are producing sperm, it can be retrieved with testicular sperm extraction (TESE).

Causes of Y-chromosome microdeletion (YCMD)

Y-chromosome microdeletion is caused by mutations in the Y chromosome (the male chromosome), typically affecting the azoospermic factor (AZF). AZF is a gene responsible for making proteins that regulate sperm production and development. Gene deletions or mutations in this area can lead to Y-chromosome-related infertility.
Patients with Y-chromosome microdeletions do not typically experience any symptoms other than infertility, making it tricky to detect. A semen analysis (SA) along with genetic testing can help diagnose the condition. In addition, patients with this condition may have smaller testes, as the spontaneous mutations to the Y-chromosome hinder sexual development.

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