Preimplantation Genetic Testing for Monogenic Diseases (PGT-M), previously known as Preimplantation Genetic Diagnosis (PGD), is a test deigned to lower the risks of passing hereditary genetic diseases to a child.
WHEN IS PGT-M PERFORMED
When a couple is aware of close or distant relatives monogenic diseases, that is, disorders caused by single gene modification they may be at risk of having a child affected by the genetic disorder. Preimplantation Genetic Testing for Monogenic Diseases (PGT-M) is used to reduce the risk of transmitting such diseases.
Preimplantation Genetic Testing for Monogenic Diseases (PGT-M) is prescribed in the following cases:
- If you and your partner have the same hereditary autosomal recessive disease (cystic fibrosis, for example)
- If you have an X chromosome-linked disease (Duchenne muscular dystrophy, for example)
- If you or your partner have any autosomal dominant disease (Huntington’s disease, for example)
- If your or your partner’s family has a history of inherited tumor syndrome (BRCA1 and 2, for example)
- If you have a child with a homogenous disease, or you have been pregnant with a fetus suffering from a homogenous disease.
PGT-M AT REPROART CENTER (PGT-M)
The specifics of Preimplantation Genetic Testing for Monogenic Diseases (PGT-M) vary by family. If a given family has a disease with no genetic information about it available, a unique diagnostic kit (a set of reagents) is created for the family. To this end, DNA samples of both partners and their families are extracted.
To avoid monogenic diseases from affecting a child in the family, a couple must have In-Vitro Fertilization (IVF) at ReproART. Preimplantation Genetic Testing for Monogenic Diseases (PGT-M) is performed on embryos developing in the lab.
When a patient receives In-Vitro Fertilization (IVF) at ReproART, the embryo’s development up to a certain stage proceeds outside the body, in the IVF Laboratory. That is when the embryo’s biopsy is performed.
On the third day of the embryo’s development, assisted laser hatching is performed on a small section of the outermost layer that surrounds but is not part of the embryo. On day five or six, when the embryo reaches the blastocyst stage, trophectoderm biopsy is performed, removing a few cells that extend through the hole in the outermost layer. The trophectoderm is a constituent part of the blastocyst, which subsequently becomes the placenta. Subsequently, the biopsied cells are sent for genetic testing to our partners, leading laboratories in Great Britain or United States of America, with whom we maintain active cooperation.
Although cells that would have become placenta are removed the cells that will become the fetus and the baby are not harmed. Following biopsy embryos are cryopreserved until genetic test results are reported. Upon thawing embryos recover and develop normally.
The genetic testing lab may take several weeks to several months to prepare the testing for your embryos. Next, so-called genetic fingerprinting for each mutation is performed, with each embryo diagnosed to identify whether or not it has been damaged.