Specialized Genetic Counseling and Laboratory Services
Introduction to the Genetics Laboratory
The Genetics Laboratory at Shiraz Infertility Treatment Center is comprised of the country’s top genetics specialists. The methodologies employed in this department are among the most advanced currently practiced in the world. By leveraging the expertise of leading specialists, state-of-the-art facilities, and the latest global scientific knowledge, our Genetics Laboratory has been able to bring smiles to the faces of countless families.
Karyotype Test
(PND) Diagnosis Genetic Prenatal
Preimplantation Genetic Diagnosis (PGD)
Why Is Genetic Counseling Important?
In genetic counseling, valuable information is obtained by gathering details from the client’s family history and prescribing and analyzing appropriate genetic tests. After evaluation, this information can be used to identify the risk of genetic disorders in future generations.
Genetic disorders are divided into two main categories: chromosomal abnormalities and single-gene disorders. Since the vast majority of genetic diseases have no cure and can impose severe hardships on both patients and their families, the role of genetic counseling in preventing these conditions is absolutely crucial.
Types of Genetic Counseling
Genetic counseling can be divided into several general categories:
- Diagnostic Counseling
- Pre-marital Genetic Counseling
- Preconception Genetic Counseling
- Prenatal Genetic Counseling
In this type of counseling, the goal is to identify genetic defects in the patient’s genome. Based on the individual’s medical history and symptoms, appropriate genetic testing can determine whether a condition has a genetic origin. Examples include blindness, hearing loss, metabolic disorders, and developmental delays in children.
Many cases of intellectual disability are caused by genetic disorders, which can be identified through appropriate testing. For certain cancers, the link between specific genes and cancer development has been established. These genes can be analyzed using specialized genetic tests, meaning that mutations in these genes play a significant role in cancer formation. In some cancers, genetic testing can help guide more effective treatment choices and also assess the likelihood of hereditary transmission.
Couples can seek genetic counseling before marriage and undergo relevant testing if needed. This helps them become aware of the risk or likelihood of having a child with genetic disorders to a great extent.
Having a healthy child is one of the most important concerns for all couples. Through genetic counseling and, if needed, appropriate genetic testing, this goal can largely be achieved. While all couples are recommended to consult a genetic counselor before attempting pregnancy, this is strongly advised for some couples in particular. Important indications include:
- Couples with a history of recurrent miscarriages or stillbirths
- Infertile couples
- Couples with multiple unsuccessful embryo transfers through in vitro fertilization
- Couples with close family relationships
- Couples who are distantly related but have a history of genetic disease in family members
- Couples with a close relative affected by a genetic disorder, genetic abnormality, or intellectual and physical disability
- Couples with a family history of early-onset cancer
- Couples who are both carriers of the same genetic disorder (e.g., thalassemia)
- Couples in which one partner has a chromosomal abnormality
- Couples with a history of an affected child (physically or intellectually) or a pregnancy with an abnormal fetus
As mentioned, preconception counseling is one of the key steps toward having a healthy child. However, genetic counseling during pregnancy can also be extremely helpful in certain situations, including the following:
- Maternal age over 35 years
- Positive results in prenatal screening tests
- Abnormal results in ultrasound during pregnancy
All the indications mentioned earlier for preconception genetic counseling also apply to prenatal genetic counseling. However, it is important to note that seeking counseling during pregnancy may not be timely for certain situations, such as investigating inherited genetic disorders. This is because some tests—for example, assessing a fetus for a specific inherited condition—typically require initial testing of both parents to identify the mutation, followed by fetal testing for that same mutation. These procedures are time-consuming, and it is strongly recommended that couples begin the genetic counseling process and undergo any necessary testing before attempting pregnancy.
What Steps Are Needed After Genetic Counseling?
If genetic counseling and necessary testing reveal that a couple is at risk of having a child with genetic disorders, they will be provided with various options and guidance. Ultimately, the couple can make an informed decision by choosing one of the following two approaches:
Preimplantation Genetic Diagnosis (PGD) makes it possible to examine the genetic status of embryos before they are transferred to the mother’s uterus. In fact, PGD involves performing genetic testing on cells taken from 3 to 5-day-old embryos obtained through IVF/ICSI, followed by the transfer of genetically healthy embryos into the uterus. Therefore, in this procedure, embryos created through in vitro fertilization are genetically screened prior to uterine transfer.
It is important to note that for certain genetic disorders, legal permission for pregnancy termination is not granted. Therefore, if fetal abnormalities are detected during pregnancy, it may not be legally possible to terminate the pregnancy and prevent the birth of a child with these conditions. In such cases, PGD is typically recommended, as it allows only genetically healthy embryos—free from the disorder in question—to be transferred to the mother’s uterus.
Today, this technique not only allows for gender determination but also enables the screening of chromosomal abnormalities (both numerical and structural) in embryos, as well as the analysis of many single-gene disorders. In fact, PGD is the only reliable method to prevent the birth of children affected by genetic disorders without the need for therapeutic abortion. It helps physicians select healthy embryos for transfer to the uterus in patients undergoing assisted reproductive treatments.
Prenatal Diagnosis (PND) refers to diagnostic testing performed during pregnancy, before the child is born. In fact, it involves assessing the presence or absence of genetic disorders in the fetus during gestation. When prenatal genetic diagnosis is required during pregnancy, sampling is performed either from the chorionic villi (CVS) or from the amniotic fluid surrounding the fetus (amniocentesis).
Genetic Laboratory Procedures
1- If the embryo is of good quality, the biopsy process, which involves removing a cell from an 8-cell embryo, does not harm the embryo's organs. In the worst-case scenario, it may prevent the 3-day-old embryo from developing further.
The gender and chromosomal status (chromosomes 13, 18, and 21) of each embryo will be reported to both the patient and the embryology department by the genetics laboratory on the morning of the transfer day.
3- The final number of embryos suitable for biopsy may be lower than the initial number due to poor embryo quality, failure to develop, or failure to recover from freezing.
4- In some cases, for the reasons stated below, there may be no embryos available for transfer after genetic testing:
- The embryo may be chromosomally normal but not of the desired sex.
If an embryo matches the desired gender but has genetic abnormalities in chromosomes 13, 18, or 21, it will not be eligible for transfer.
- The embryo may be of the desired sex but its growth may have stopped in culture, making it unsuitable for transfer.
5- Since genetic testing involves the use of genetic kits and many other consumables, there is no refund if no healthy embryos are available for transfer.
1- Array CGH test: This test is used to analyze the number of all chromosomes.
2. Single-Gene Testing: This method is used to detect mutations in a specific gene. All embryos are cultured until day 5. Once they reach the appropriate stage for biopsy, 4-8 cells are carefully separated from each embryo (as shown in the image) and sent to the genetics laboratory for analysis. The embryos are then frozen until the genetic test results are ready.
After genetic testing and the results are ready, the patient will be contacted to arrange for embryo transfer.
1- Approximately 40% of cultured embryos reach a stage where they can be biopsied. (It's important to note that embryos that don't reach day 5 lack the necessary quality for continued growth.)
2. After biopsy, the embryos are frozen, and the samples are sent to the genetics laboratory for analysis.
3. After array CGH analysis, it is possible that none of the embryos have a balanced chromosomal count. Similarly, in molecular PGD for specific genetic disorders, there may be no normal embryos available. In such cases, embryo transfer will be canceled.
4. An embryo may be reported as genetically and chromosomally normal by the genetics laboratory, but after thawing, it may not be suitable for transfer due to poor quality.
5- Due to the use of genetic kits and numerous consumables in the array CGH and molecular testing processes, no refunds will be provided if there are no healthy embryos available for transfer.