Preimplantation Genetic Testing of Embyros (PGT-M and SR)

What is it?

Preimplantation Genetic Testing for Monogenic (single gene) conditions (PGT-M) offers advanced genetic testing of embryos for patients who are either carriers or are affected by a genetic condition. PGT-M can be used to screen for most known inherited genetic conditions. It is used to reduce the risk of having a child that is affected by an inherited condition.

Preimplantation Genetic Testing for Structural Rearrangements (PGT-SR) offers advanced genetic testing of embryos for patients who have a chromosomal rearrangement. Chromosomal rearrangements can be caused by translocations, inversions or microdeletions. Individuals with a structural rearrangement are at risk of producing embryos with the incorrect amount of chromosomal material, which typically do not lead to a successful pregnancy. PGT-SR helps to identify embryos with the correct chromosomal material that are likely to lead to a pregnancy and healthy baby.

How is it done?

Prior to starting treatment, you must complete feasibility/test development specific to the gene or structural rearrangement that is being tested for.

There are then four stages involved in a PGT-M and PGT-SR treatment cycle:

1. An egg (oocyte) collection procedure to create embryos.
2. Embryos that develop to the blastocyst stage and are of suitable quality can be biopsied. A small number of trophectoderm cells (cells from the outer layer of an embryo) are biopsied from the embryo to be tested. The biopsied sample is tested to determine whether the specific gene or structural rearrangement is present in the embryo. The unaffected embryos are also PGT-A tested to determine if the number of chromosomes are normal (euploid).
3. Once the results are received, embryos that are unaffected by the gene or structural rearrangement can be transferred in a Frozen Embryo Transfer cycle. Any additional unaffected embryos will remain frozen and stored for future use.

Who is eligible for PGT-M and SR?

The Western Australian Reproductive Technology Act 1991 (amended 2004) allows the following patients to access PGT-M or SR:

• PGT-M is allowed where there is a serious known monogenic disorder in the family (for example, cystic fibrosis, Huntington’s Disease, fragile X. SMA etc.)
• PGT-SR is allowed where there is a structural rearrangement (translocation, inversion or microdeletion) in one of the parents.

How is PGT-M and SR managed at Concept Fertility?

PGT-M or SR should be discussed with your fertility specialist followed by a meeting with the Scientific Director.

PGT-M feasibility / test Development

Concept will work together with you and our partnering genetics laboratory to develop a specific test for the gene (PGT-M) or identify the structural rearrangement (PGT-SR). For the test development genetic reports and a blood or cheek swab sample may be required from you and some of your family members.

Pre-IVF cycle consultations

Subsequent consultation with your fertility specialist may be advised following the feasibility/test development phase so your doctor can advise you about the IVF cycle process and provide treatment orders for an IVF cycle.

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