What is SAT test?
ЅАТ (Ѕреrm Аnеuрlоіdу Теѕt) is a diagnostic method for studying the genetic origin (etiology) of male infertility. In particular, this test provides an analysis of the percentage of spermatozoa with cerebral anomalies in the seminal vesicle. This assessment allows us to assess the risk of transmission of brain anomalies in the generation. The study analyzes chromosomes, which are most often associated with spontaneous abortions and lead to chromosomal anomalies in the chromosomes (x, 21, ym 18).
Purpose and benefits of the test
In clinical aspect, increasing of the percentage of the spermatosoids with chromosomical anomalies is connected with the decrease of the percentage of pregnancies and a higher risk of spontaneous abortions with couples using the ICSI treatment method. (Rubіо еt аl., 2001; Вurrеllо еt аl., 2003; Реtіt еt аl., 2005; Nісороullоѕ еt аl., 2008; Rоdrіgо еt аl., 2011; Rоdrіgо еt аl., 2013).
At the embryonic level, various defects are observed according to the type of chromosomal anomaly in the spermatozoa. For example the increase in the percentage of the spermatosoids with sexual dysomy, leads to increasng levels of aneyploid embryos with syndromes, which are compatible with life(Patau syndrome, Dawn syndrome, Edwards syndrome, Kleinfelter’s syndrome, Turner syndrome and Tpisomy of X and Y xpomosomes). The increase in diploid spermatozoa leads to an increase in the probability of the development of triploid embryos and especially to abortion (Rоdrіgо еt аl., 2010).
In the context of the generation, several studies have been conducted on parents with the syndrome of Dawn, Kleinfelter or Turner, which showed an increase in chromosomal anomalies in spermatozoa.
Due to these reasons, the SAT test is useful for genetic counseling of men with infertility and for finding an optimal treatment for them.
Indications – who and when?
This is a diagnostic test for male infertility and is recommended for patients with high risk of spermatozoa. This is mostly the case with men with abnormalities in the seminal parameters – mainly oligozoospermia, non-observable azoospermia and severe teratozoospermia.
Other indications for taking the test, which are not necessarily related to violations in the seed parameters:
- In case of recurrent abortions of unknown etiology;
- With couples with multiple unsuccessfull IVF cycles;
- With couples with precursor pregnancy with chromosomopathy.
In comparison with the classical study of meiosis, this test has the advantage of evaluating the final product of meiosis. In order to obtain clinically significant results, we analyze a total of 2,000 spermatozoa for each chromosome, in two separate and independent cases. The percentage of chromosomal abnormal spermatozoa is equal to that of the control group, which has normozoospermia, in order to assess statistical differences.
The most important steps in the protocol are:
- Fixation of spermatozoa on laboratory glasses
- Decondensation of spermatozoid cores
- Hybridization with fluorescent DNA samples directly directed to the analyzed chromosomes
- Fluorescent signal detection, evaluation and interpretation with epifluorescent microscope with special filters
This technique allows aneyplodia to be performed with precisely defined xpomosomes included in the test. Rarely there is a chance of not enough spermatosoids in the semen sample for the correct measurement of the risk form aneuploidy.
Application of ЅАТ in Bulgaria
For the first time in Bulgaria the genetic test for chromosomical anomalies in the spermatozoa SAT is available in the specialized hospital for reproductive medicine “Sofia” in collaboration with the world leader in repproductive genetics Igenomix.