Among male infertility causes, there are about 10% – 15% of cases of infertility (there is no sperm in semen) and 5% of severe infertility (sperm density <5 million / 1ml of semen) due to Usually genetic material. In order to determine the cause of infertility in men in the past, patients were familiar with chromosome testing indications. However, there are cases of mutations that have lost a small segment on the chromosome, especially a small segment on the Y chromosome that cannot be detected by cellular genetic engineering. With the continuous advancement of molecular biotechnology, it is possible to detect small fragments on the Y chromosome microdeletion in the AZF (Azoospermia factor) region, contributing to identifying the causes of infinity cases. male births that were previously classified as unexplained infertility. Wishing to serve the best in genetic diagnosis and counseling. GENOME Science, Technology and Services Co., Ltd. has been implementing AZF test – a new test in the diagnosis of male infertility.
What’s AZF ?
AZF stands for the English word (Azoospermia factor), which refers to the AZF region on the long wing of the Y chromosome, which contains many important genes that govern normal sperm production in men gender. When missing the Y chromosome segment in the AZF region, depending on the type of segment loss in the region of AZFa, AZFb, AZFc, AZFd will cause consequences with different levels such as infertility, severe lack of sperm. or sperm dysfunction leads to infertility in men.
Mutation is missing in the AZFa region, it will lead to infertility and simple Sertoli syndrome (testes have only cells that help support sperm growth but not sperm). If a segmental loss occurs in the AZFb region, a small segment will appear halfway through spermatogenesis, and a large segment will lead to infertility.
Mutations that occur in AZFc, AZFd can cause diverse manifestations in men, sperm may be normal, mild sperm deficiency, severe sperm deficiency or infertility.
In some cases, loss of associated fragments may occur, such as loss of AZFb + c region, AZFa + b + c segment loss.
Why should the AZF paragraph loss test be performed?
Among genetic causes of male infertility, the AZF mutation is the second leading cause of infertility after Klinefelter Syndrome. Performing the AZF deletion test will help determine whether the cause of infertility in men is due to the missing AZF segment mutation on the Y chromosome.
Because of the effects of a mutation mutation that occurs in different AZF regions, it will have different effects on male reproductive function. Therefore, it is necessary to conduct a test to determine exactly where the fragment mutation occurs at, assess the level of influence to choose the correct treatment. If the segmental mutation occurs in the AZFa region, the AZFb region or the conjugated mutation mutation, the man will not be able to have sperm and cannot have children. The treatment should be stopped because it will not bring results and be costly to the patient. But if deletions occur in the AZFc region, 70% of cases can find seminal cells, which will be biopsied, aspirated and then cultured in special environments to differentiate. into sperm. The sperm can be used in vitro fertilization or used to treat internal medicine stimulate sperm.
Thus, the AZF segment loss test is an important male infertility test, helping to identify the cause of infertility, orienting the physician to appropriate treatment, reducing the cost of ineffective treatment for patients. When patients with AZF mutation are successfully treated and can have children, if a girl is born, there will be no sex chromosome Y so it will not be affected, however if it is a boy, she will move. pass the Y mutant gene and will later be infertile. Therefore, the AZF section test is the basis for doctors to give genetic advice to patients, help patients understand their situation and choose the most appropriate treatment.
The AZF section loss test is indicated for the case?
AZF section loss tests are indicated in the following cases:
– Men who are infertile, do not have sperm in the semen is not caused by heavy obstruction or lack of sperm (semen contains less than 5 million sperm / ml)
– Before surgery to remove varicose veins in patients with varicocele, the AZF test is used to screen for doctors to decide whether or not to perform this surgery on patients, because if the cause Infertility is due to the AZF mutation mutation, so that removing varicocele does not improve sperm weakness.
– In a family with an older brother or younger brother who has a sudden loss of AZF, a family history of multiple abortions, deformities or mental retardation.