Preimplantation genetic technologies are increasingly used with in vitro fertilization.
Approximately one-fourth of PGT cases are performed for couples at risk for one or more single-gene disorders.
Preimplantation genetic testing (PGT) examines embryos during in vitro fertilization (IVF) before possible transfer to a woman’s uterus for a range of genetic problems that can cause implantation failure, miscarriage and birth defects in a resulting child
Preimplantation genetic testing refers to the three types of tests that may be performed on embryos during IVF:
Preimplantation genetic screening for abnormal chromosome number (PGT-A)
Preimplantation genetic testing for monogenic (individual) disease (PGT-M)
Preimplantation genetic testing structural rearrangement (PGT-SR) for known chromosomal mis-arrangements such as
inversion and translocation.
chevron_rightFor patients with a normal uterus and with normal endometrial thickness
(≤6mm), in which no problems are apparent.
chevron_rightFor patients who have had implantation failure with embryos of good morphological quality (at least 3 failed embryo transfers for women younger than 37 years or 2 failed transfer in women older than 37 years).
chevron_rightFor patients with a positive history of chromosomal aneuploidy or a genetic disorder in the family.
Many limitations exist to preimplantation genetic testing and include challenges in detecting microdeletions and
microduplications, de novo variants, and imprinting disorders. An emerging problem has been detection of mosaicism during
preimplantation genetic testing-aneuploidy
Types of PGT
PGT-A (Preimplantation Genetic Testing for Aneuploidy) is best employed in IVF settings and allows the determination of the
chromosomal status of IVF embryos by screening all 23 pairs of human chromosomes. Only embryos with the correct number
of chromosomes will be able to develop into a healthy baby. PGT-A test is able to identify those embryos free from
chromosome abnormalities that are more likely to implant and result in a healthy live birth.
chevron_rightCouples seeking IVF treatment.
chevron_rightEmbryo screening would improve the chances of achieving a successful pregnancy in all IVF patients.
chevron_rightIt is particularly suitable to help couples with recurrent pregnancy loss, couples with previous IVF failure attempts, women of advanced reproductive age (>35), couples with family history of chromosome. problems
Embryo biopsy at Blastocyst → stage Biopsied cells into the PGT-A tube → Sample shipment at 4 degree → Analysis of DNA in the biopsied cells → Turnaround time(TAT) =10working days → Post-test Genetic counseling.
chevron_rightImproves IVF success, increasing the likelihood of pregnancy
chevron_rightReduces the risk of miscarriage
chevron_rightAllows for confident single embryo transfer, reducing the risks and complications associated with multiple pregnancies.
chevron_rightReduces time to pregnancy by allowing the identification of a normal embryo as soon as possible.
chevron_rightAvoids the live birth of a baby with genetic disorders
A genetic test designed to reduce the risk of having a child with an inherited condition. PGT-M (formerly PGD) is an early genetic
diagnosis test for embryos produced during IVF, prior to their transfer to the uterus.By analysing DNA from each embryo, normal
embryos can be preferentially selected to be transferred and begin the journey towards conceiving a healthy child.
The more frequent indications for which PGT-M are currently applied are cystic fibrosis and hereditary hemoglobinopathies for
the autosomal recessive disorders, and myotonic dystrophy type 1, neurofibromatosis, Huntington’s disease, and hereditary
cancer syndromes for the autosomal dominant disorders. For the X-linked disorders, PGT is mainly carried out for Duchenne’s
muscular dystrophy, hemophilia, and fragile X syndrome.
chevron_rightIdentify embryos affected by a known familial genetic difference to avoid transfer of an “abnormal” embryo.
chevron_rightAny couple at risk for passing on a genetic disease or condition could benefit from PGT-M.
chevron_rightCarriers of single gene defects.
chevron_rightThose with chromosomal disorders.
chevron_rightWomen experiencing recurrent pregnancy loss associated with chromosomal concerns.
chevron_rightRequires customized test development for EVERY patient
chevron_rightVariants of unknown significance (VUS) – mutations that we don’t know what the clinical outcome may be
PGT-SR encompasses genetic testing in embryos for carriers of balanced chromosome structural rearrangements(Translocations
& Inversions).PGT-SR enables us to detect those embryos with chromosomal imbalances
Carriers of balanced chromosome structural rearrangements have a higher chance of presenting reproductive issues like infertility,
subfertility and RPL and live neonates with congenital alterations and intellectual disability.
chevron_rightIReciprocal translocation: Pieces of chromosomes have switched places.
chevron_rightARobertsonian translocation: Chromosomes link together and create an abnormal chromosome count. This can cause conditions including trisomy 13 and uniparental disomy (UPD). This type of rearrangement may also result in translocation Down syndrome.
chevron_rightInversion: Part of a chromosome is turned upside down and reinserted back into the chromosome.
PGT-SR can help identify embryos with the correct amount of chromosomal material that are most likely to lead to a successful
pregnancy and healthy live birth.
chevron_rightCommercial probes are available for only a limited number of loci, which may complicate the selection of probes for the analysis of rare chromosomal rearrangements.
chevron_rightFISH-based PGT analysis can only assess the copy number of the chromosomes targeted by the DNA probes used.
chevron_rightFISH-based PGT-SR analysis does not allow for the detection of uniparental disomy (UPD).
chevron_rightArray-based PGT-SR analysis is less sensitive to detect mosaicism than NGS.