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Genetics · Preimplantation Genetic Diagnosis Clinic

Genetics-Preimplantation Genetic Diagnosis Clinic
analyzes the chromosomes of the embryo
to diagnose chromosomal abnormalities.

For inquires:
031-782-8300(KOR) / +82-10-8866-2268(ENG)
Introduction
PGT 진행 과정
Preimplantation
Genetic Test (PGT)
As women age, the chance of chromosome abnormality increases. If there is a chromosomal abnormality in the embryo, the success rate of pregnancy decreases, and the rate of natural abortion increases. PGT is a procedure performed when the risk of chromosomal abnormality in the embryo is high, and unsuccessful pregnancy or habitual miscarriage is a concern.
In the method of diagnosing chromosomal abnormalities from embryos and transplanting only normal embryos, a FISH technique diagnoses only partial chromosomes, but recently, NGS technique is widely used as it can diagnose all 46 chromosomes.
Chromosome screening before implantation increases the implantation and pregnancy rate during IVF procedure, and reduces the rate of miscarriage, thereby increasing the birth rate of healthy babies.
PGT Before
Implantation
  • When a chromosome abnormality is suspected or when there is a history of being pregnant with a fetus with chromosome abnormality
  • Advanced maternal age
  • Recurrent miscarriage
  • Recurrent implantation failure
  • Rare nonmotile sperm
Chromosome abnormalities (Down syndrome, Edward syndrome, Patau syndrome, etc.)
Human chromosomes represent two bound cells as 1 set(n) with a total of 46 normal cells consisting of a total of 23 sets of chromosomes (2n=46) A numerical abnormality of 2n chromosomes means that the number of chromosomes is not a normal 46 and is largely separated from polyploidy.
Polyploidy
As a set of abnormal chromosomes, triploids (triploidy, 3n=69) and tetraploidy (tetraploidy, 4n=92) are typical. Most of them are found in fetuses miscarried in the early stages of pregnancy.
Aneuploidy
This is when there is a presence of an abnormal number of chromosomes in a cell, for example a human cell having one more (2n+1=47) or one less (2n-1=45) chromosomes instead of the usual 46. Most cases of aneuploidy results in miscarriage in the early stages of pregnancy or no pregnancy at all.
However, some trisomy, such as Down Syndrome (trisomy 21), Patau Syndrome (trisomy 13), and Edwards Syndrome (trisomy18) can maintain pregnancy and give birth, but the baby will have severe deformities or mental retardation and, except for babies with Down Syndrome. will die soon after birth.
The autosomal chromosome is not normal and likely to miscarriage during early pregnancy. However, unlike autosomal chromosomes, most sex chromosome aneuploidy (Turner Syndrome, 45, X; Klinefelter Syndrome, 47, XXY; 47, XXX; 47, XYY) can maintain pregnancy and give birth, and compared to autosomal aneuploidy, symptoms are very weak or very rare, but still can cause infertility.
PGT for Fetus’ Safety
The incidence of deformities in babies born with having PGT is similar to that of babies being born through routine IVF procedure or intracellular sperm implantation (ICSI), and is also reported to have a similar incidence to that of the general population.
Next Generation Sequencing (NGS) Schematic Diagram
The chromosome test before implantation is a method of collecting and diagnosing a small number of cells from the embryo. Due to the technical limitations of the test method itself, it should be conducted after consulting with the attending physician and if successfully pregnant, amniocentesis is required to confirm that the results are again within the normal limits.