Preimplantation genetic testing for monogenic or single gene defects is a technique that allows us to assess an embryo for genetic conditions known to run in your family, thus reducing the risk that these conditions will be passed on to your offspring. Formerly, PGT-M was known as preimplantation genetic diagnosis (PGD).
Each one of us has a genetic blueprint — an ‘instruction manual’ that makes us uniquely human and determines our individual characteristics. Small errors in this blueprint, otherwise known as genetic mutations, can result in a wide range of genetic diseases. Given we inherit our genetic blueprint from our parents, these genetic mutations and diseases may be passed on from parent to child.
PGT-M involves taking a biopsy of the embryo (5–7 cells from the outer layer) after it has grown and developed for 5–6 days. From this sample, we can analyse the genetic material of the embryo and determine whether a genetic mutation is present in the DNA or not. In doing so, we can prevent the transfer of embryos that have the genetic mutation.
PGT-M does carry some risks, including:
Embryos are fragile, so any procedure that involves handling the embryo and disturbing its surrounding conditions poses the risk of harm. However, while the risk of harm will always exist, it is thought that the overall risk of damage to the embryo is minimal.
When we conduct testing on a sample of cells from the embryo, we are assuming that this sample is representative of all the cells in the embryo. However, a condition called mosaicism may exist, where some of the embryo’s cells have the genetic mutation and some of the cells do not. Testing of embryos that display mosaicism can result in an inaccurate or unclear test result.
The results of the genetic testing may return as ‘indeterminant’, meaning the test could not determine whether the genetic material of the embryo was normal, or abnormal. This may occur for a variety of reasons, including a poor-quality embryo.
We may recommend PGT-M when a genetic disease, such as haemophilia, thalassaemia and cystic fibrosis, runs in the family and it has been determined that the offspring could be severely affected. This may be determined with the help of a genetic counsellor and geneticist. Feasibility testing is also required prior to PGT-M to see if your particular genetic condition and variant can be tested for. Your Newlife IVF fertility specialist will assess the specifics of your situation with you and make a recommendation accordingly.
You can visit our fees page for more information. However, please contact us directly to discuss PGT pricing specific to your circumstances.
*Fees correct as of 1 January 2024; reduced rates may apply depending on eligibility (in line with new Medicare rebates effective 1 November 2021), as well as the number of embryos tested.
Preimplantation genetic testing (PGT) is a broad term for a range of scientific techniques available during IVF to identify genetic abnormalities in embryos before they are transferred into the uterus.
PGT may be requested by couples or individuals who are at risk of passing on a genetic condition or structural chromosome rearrangement to their offspring. PGT may also be used to assess the number of chromosomes in an embryo.
PGT-M is a genetic test for your embryo designed to check for a known monogenetic or single-gene condition in your family, such as cystic fibrosis or spinal muscular atrophy. It can reduce the chance of a child being affected by a genetic condition.
Preimplantation genetic testing for monogenic or single-gene conditions (PGT-M) was previously called preimplantation genetic diagnosis (PGD).
Yes, it is possible to perform both preimplantation genetic testing for aneuploidies (PGT-A) and preimplantation genetic testing for monogenic or single-gene conditions (PGT-M) on the same embryo.
In fact, performing both PGT-A and PGT-M on embryos can provide a more comprehensive evaluation of their genetic health. At Newlife IVF, embryos are first tested for PGT-M. If no genetic defects are detected, embryos then undergo PGT-A.
Once an embryo (created as part of an IVF cycle) has reached the blastocyst stage (usually after 5–6 days of growth), a few cells are removed from the embryo. The cells obtained are then analysed using the PGT-M technique. Based on the results, your genetic counsellor and fertility specialist can advise which embryos are suitable to transfer into your uterus.