Genetic Diagnostic Techniques
Genetic diagnostic techniques
Genetic diagnostic techniques are being used for patients and for examining embryos. Genetics is becoming an indispensable diagnostic tool in modern medicine. Current research is even pointing towards its therapeutic use.
It is not surprising to incorporate these techniques into the field of Reproductive Medicine. For this reason, Novafem fertility and genetics medical center, offers genetic diagnosis techniques applicable to patients, gametes, embryos and / or fetuses. The techniques used in genetic diagnosis within Reproductive Medicine are diverse. Among them we have:
1. Detection of infectious microorganisms within the reproductive system of the couple
Currently, there is more knowledge of the presence of various microorganisms that are responsible for inflammatory processes in the male and female reproductive system which cause the infertility of the couple. Examples are Chlamydia trachomatis, Ureaplasma Urelyticum, Mycoplasma Genitalium and Neisseria gonorrhoeae. Specialists take these microorganisms into account at the time of making the diagnosis of the possible causes of infertility of the couple. Novafem, fertility and genetics medical center in the company of Celagem, offers a multiplex called fertiplex of the couple that diagnoses these microorganisms jointly in a single sample of cervical swab or semen. In recent studies carried out by our institution, the incidence and prevalence of these microorganisms that attend 4 units of fertility in the reproductive system of the couple is divided in: 16.5% of incidence of infections caused by these microorganisms with a prevalence of 14.25%, 2,25% and 1% for Ureoplasma Urealiticum, Chlamydia Trachomatis and Mycoplasma Genitalium respectively. Similarly, the incidence of chronic viral diseases such as Hepatitis C, Hepatitis B and HIV, is very common in the Latin American medical reality, which forces us to take into account the need of these couples to have offspring. This is why Novafem, fertility and genetics medical center, offers the service of analysis, quantification and sperm washing for all those couples that are infected by these viruses. These techniques guarantee that your offspring will be free of the mentioned infections.
2. Blood cell karyotyping method, amniotic fluid and the remains of abortifacient
The blood cell karyotyping method is a cytogenetic test that is performed on individuals to identify chromosomal abnormalities as a cause of malformations or diseases. The results of the karyotype may indicate genetic changes associated with a disease. The fetus is researched to prenatally diagnose chromosomal alterations through the karyotype. In the case of amniotic fluid, the sample is obtained by the use of an eco-guided puncture to obtain the amniotic fluid between fourteen and eighteen weeks of pregnancy. At least three primary cultures are analyzed to complete twenty metaphase cells and to identify numerical and structural alterations of the chromosomes. This is the same test as the previous one, which is performed on the fetus in cases of recurrent abortion to look for chromosomal alterations by performing the karyotype. The sample is collected from the abortion tissue after a curettage. It can also be performed on the skin when the aborted fetus is developed.
3. FISH study for sperm
This test is performed by the FISH technique to research the sperm. It determines the numerical constitutional anomalies which are part of the chromosomes. The study is performed in decondensed nuclei for chromosomes 13, 18, 21, X and Y. The results obtained in infertile individuals with normal karyotype have shown increases in the frequency of aneuploid and diploid sperm, although associated with important interindividual variations. On the other hand, its application in carriers of constitutional chromosomal anomalies allows to obtain reliable data on the frequency of chromosomally unbalanced gametes produced in each particular case. FISH studies on spermatozoa are usually indicated in severe male factors, with the aim of obtaining direct information on the incidence and production of chromosomally abnormal gametes before the use of assisted reproduction techniques, especially for ICSI candidates.
4. Microdeletion of the Y chromosome
This test consists of the analysis of regions and genes present in the Y chromosome, such as AZF (Azoospermia Factor), responsible for the proper development and maturation of sperm.
5. Sperm DNA Fragmentation Study
The fragmentation of sperm DNA refers to breaks or lesions in the genetic material of the sperm. The greater the number of injuries, the lower the integrity of the genetic material and therefore the lower the probability of a full-term pregnancy. There are several methods to measure fragmentation levels. In Novafem fertility and genetics medical center, we used the tunnel study, which is a test with great clinical projection that has been widely evaluated and recommended by leaders in studies of DNA fragmentation. Using this system, an individual who presents 30% or more of the sperm with fragmented DNA, their probability of achieving a full-term pregnancy is less than 1%, both in natural fertilization and assisted reproduction techniques. This test is recommended in the following cases:
- Idiopathic infertility (of unknown cause).
- Repeated failures in assisted reproduction techniques.
- Cases where an embryo with a deficient quality has been observed.
- Patients who have suffered repeated abortions.
- Men older than 45 years.
- Febrile episode in the last 3 months.
6. Preimplantation Genetic Diagnosis (PGD)
Preimplantation Genetic Diagnosis (PGD) is an innovative technique for detecting genetic anomalies prior to the transfer of the embryo into a woman’s uterus. It is a technique used as a complement to in vitro fertilization (IVF). The realization of a PGD is recommended if there is a possibility that your embryos are going to be affected by certain chromosomal characteristics or genetic diseases. These characteristics can prevent the implantation of embryos cause the loss of pregnancy, the birth of a child with physical problems and / or mental retardation or affection of a genetic disease. PGD can help prevent these adverse outcomes by identifying affected embryos during their development in the laboratory and before being transferred in an IVF cycle. The four main causes when a PGD is advised are the following:
- Infertile patients with a history of repeated spontaneous abortions.
- Carriers of translocations, inversions or other chromosomal anomalies, or monogenic diseases.
- Patients of an IVF cycle, older than 35 years, more than five zygotes and without previous history of repeated failure of implantation.
- Men with severe alterations in their seminal quality.
The studies that are usually carried out on embryos using DPI techniques are Aneuploidies and the study of monogenic diseases.