Perhaps many people do not understand Klinefelter's syndrome when it comes to it. As soon as a boy is born, parents often look more at the external genitals (which is a small sign of masculinity), but they ignore the "incurable disease" that affects male fertility - Klinefelter's syndrome.
In the andrology clinic of a reproductive center, doctors often encounter patients with fair skin, tall stature, thin bones, relatively long limbs, sparse beard, pubic hair, and axillary hair, inconspicuous laryngeal nodules, enlarged breasts, narrow shoulders, and wide hips... Experienced andrologists can often quickly infer whether a patient has Crohn's disease. Most patients with Klinefelter's syndrome come to the reproductive center clinic because they are infertile after marriage or have been diagnosed with azoospermia. So, what is Klinefelter's sign? Is there any treatment for Klinefelter's syndrome?
● What is Klinefelter's sign?
◆ Klinefelter syndrome is a disease caused by sexual chromosome abnormalities. The chromosome number of homozygous Klinefelter syndrome patients is 47XXY, which is caused by the non separation of the X chromosome during the growth and development of sperm or eggs. The chromosomes of patients with chimeric Klinefelter's syndrome are: 46, XY/47, XXY/48, XXYY, etc. The reason is that the X chromosome does not separate during the mitosis of the fertilized egg. Some patients with chimeric Klinefelter's syndrome may find sperm in semen tests; However, patients with homozygous Klinefelter's syndrome often do not see sperm in semen tests, and some patients may only obtain sperm to produce offspring through hormone replacement therapy or testicular microscopic sperm extraction surgery.
The pathological mechanism of testicular damage in Crohn's syndrome is still unclear. Its individual performance is male. Before puberty, sexual hormone levels are normal, and testicular volume changes are not significant. In the middle and late stages of puberty, there are significant changes in hormones, a significant reduction in testicular volume, and a sharp decrease in the number of germ cells.
● incidence rate of Klinefelter's syndrome
◆ At present, epidemiological survey shows that the incidence rate of Klinefelter's syndrome is about 0.2%, accounting for about 3% of male infertility, and about 11% of non obstructive azoospermia. This disease is easily overlooked in our daily lives, and most of it is not discovered until after marriage when we become infertile. About two out of a thousand men are "Klinefelter", and the incidence rate is still quite high. The key is that parents are unable to detect the existence of such diseases. The incidence rate of Klinefelter's syndrome is so high that prenatal diagnosis and chromosome census of fetus during pregnancy are very important.
◆ And clinically, only 25% of men with Klinefelter's syndrome can be diagnosed, and some people may not know they have Klinefelter's syndrome for a lifetime. Some people don't have children without paying attention to the disease. In fact, they may have Klinefelter's syndrome, but they have not been clearly diagnosed. Less than 10% of people can be diagnosed during puberty.
● Early screening, early detection
◆ The public's awareness of screening for Klinefelter's syndrome is relatively lacking. If you miss screening during pregnancy or the neonatal period, pre puberty screening is also important.
◆ Before puberty, the testosterone level of patients with Klinefelter's syndrome is the same as that of normal boys. By mid and late puberty, their testosterone level cannot keep up, and other hormone levels also exhibit abnormal changes, resulting in impaired spermatogenesis. After entering puberty, normal boys can proceed normally from spermatogonia to sperm cells (the process of meiosis), while patients with Klinefelter's syndrome cannot complete the meiotic process of spermatogenesis and stagnate at a certain stage. "Only some localized testicular tissue can undergo meiosis to produce sperm, which explains why some patients obtain small amounts of sperm through testicular biopsy or microscopic sperm extraction.".
◆ If Klinefelter's syndrome can be diagnosed before puberty, there is still a chance to obtain cryopreservation or testicular tissue cryopreservation through hormone replacement therapy, thereby obtaining the opportunity to conceive offspring after marriage.
● Early detection and early intervention
◆ With the increase of age, the number of spermatogenic cells in patients with Crohn's disease gradually decreases, and the hyaline degeneration and fibrosis in the testis gradually worsen. The longer the time, the less chance of finding sperm. About 8% of patients with Klinefelter's syndrome may also have sperm in their ejaculated semen after puberty. At this stage, the best way for these 8% of patients is to freeze and store these sperm. If it is not possible to obtain sperm, we can only embark on the path of surgical sperm extraction - testicular micro sperm extraction (Micro-TESE).
◆ Sperm can be found in certain local lesions through testicular microscopic sperm extraction surgery. However, the proportion of sperm obtained through microsurgery is only 40% - 60%. The rate of sperm collection varies among different races and populations. At present, about 50% of the sperm obtained by micro sperm extraction surgery is reported in China.
Current research shows that during puberty in animals, spermatogonia or spermatogenic cells can be used to induce sperm. With the further development of science and technology, it is not ruled out that freezing some adolescent testicular tissue and later inducing sperm production in vitro can provide opportunities for bearing offspring. Don't give up easily, maybe the next lucky person is you.
● Will Crohn's syndrome be passed on to children?
Many people inevitably have this concern: My chromosomes are abnormal, and will the chromosomes of my child be the same as mine? There is no significant difference between the probability of chromosomal abnormalities in children born to patients with Klinefelter's syndrome and the incidence rate rate shown by epidemiological survey. Although all genetic analyses indicate that the majority of sperm produced by Klinefelter's syndrome is haploid, the necessary prenatal diagnosis during pregnancy is still a very safe practice.