In our laboratory, we have introduced a new advancement in preimplantation genetic testing for aneuploidies in embryos, which we call PGT-A Plus. This allows us to gain a more detailed understanding of the genetic makeup of the embryo and make better decisions about which embryos are suitable for transfer.
What is PGT-A Plus?
PGT-A Plus is an advanced method of genetic screening that enables the detection of chromosomal abnormalities in embryos. Compared to standard PGT-A, this method offers several advantages:
Reliable detection of ploidy errors (polyploidy/haploidy)
More accurate differentiation of meiotic and mitotic chromosomal abnormalities
Determination of the origin of chromosomal abnormalities using an additional parental sample
Determination of the genetic relatedness of embryos to the parental sample or among the embryos themselves
The PGT-A Plus method is an innovative approach that uses approximately 700,000 single nucleotide polymorphisms (SNP markers) through SNP arrays. This enables a more detailed understanding of the genetic composition of the embryo and better decision-making about which embryos are suitable for transfer. PGT-A Plus represents a significant advancement in the field of preimplantation genetic testing for aneuploidies, providing gynecologists and geneticists with more precise and informed data for making decisions about embryo transfer.
Difference Between PGT-A Plus and Standard PGT-A
PGT-A Plus allows for standard PGT-A procedures with the detection of chromosomal aneuploidies, mosaicism, and segmental chromosomal aberrations.
The key advantage of PGT-A Plus is its ability to reliably determine ploidy status and thus identify ploidy abnormalities (e.g., polyploidy or haploidy). This method also enables more accurate differentiation between meiotic and mitotic errors, which is crucial for assessing the implantation potential of embryos. Mitotic errors cause incorrect chromosomal division in embryo cells and lead to mosaicism. The implantation potential of mosaic embryos is significantly higher than that of embryos with meiotic errors, which originate in the gametes and affect all cells of the early embryo.
Additional Advantages of PGT-A Plus
PGT-A Plus provides information about the origin of aneuploidies, indicating whether they come from the mother or the father. This can be crucial for patient communication and choosing further treatment strategies.
Who is PGT-A Plus Suitable For?
PGT-A Plus, like PGT-A, is used for couples at increased risk of chromosomal abnormalities in the embryo (e.g., advanced maternal age, repeated implantation failures, pregnancy losses). Using an internally developed special algorithm, PGT-A Plus can distinguish between mitotic and meiotic trisomies. By utilizing a parental DNA sample (typically from the mother), it is possible to determine the origin of aneuploidies and identify those originating from the egg. This information can be used to optimize further IVF treatment, such as recommending egg donation.
The use of SNP markers in PGT-A Plus allows for the confirmation of genetic relatedness between embryos and verification that the parents from whom the gametes originate are indeed the biological parents of the embryo. This confirmation helps reduce the anxiety of couples about possible gamete mix-ups during the laboratory process.
PGT-A Plus cannot be used for testing media samples as part of non-invasive genetic testing of embryos (NICS).
Comments