What is PGT-M?
Preimplantation genetic testing for monogenic conditions (PGT-M) is used during IVF when a family has a known pathogenic or likely pathogenic variant associated with a specific inherited disorder.
Frequently asked questions about PGT-M
Key points
- PGT-M targets a known familial single-gene condition.
- It usually requires case-specific preparation before IVF.
- Genetic counselling is an important part of the process.
Why is test development needed?
PGT-M is usually customized to the family’s genetic finding and inheritance pattern. The laboratory may require genetic reports and DNA samples from the couple and sometimes other relatives before the IVF cycle.
How does it work?
Embryos are created through IVF, cultured to an appropriate stage and biopsied. DNA from the biopsy is analysed using a validated strategy designed for the familial condition. Embryos are classified according to whether the tested disease-associated genotype is detected.
Can PGT-M be combined with PGT-A?
In some cases, the same biopsy can be assessed for the familial monogenic condition and for chromosome copy-number abnormalities. Whether this is clinically appropriate should be discussed with the fertility and genetics team.
What are the limitations?
Allele dropout, recombination, DNA amplification limitations, embryo mosaicism, sample quality and family-specific genetics can affect interpretation. Laboratories use linked markers or other strategies to reduce error where appropriate.
Is prenatal confirmation still considered?
Because PGT-M has limitations, confirmatory prenatal diagnostic testing may be discussed or recommended after pregnancy is established.
This resource is for general education and does not replace individual medical, genetic, legal or laboratory advice.
Clinical reference sources
- ACOG \u2014 Current Guidance: Cell-Free DNA/NIPT
- ACOG \u2014 Prenatal Genetic Screening Tests
- ASRM \u2014 The Use of PGT-A: Committee Opinion (2024)
- ASRM \u2014 Indications and Management of PGT-M
- NCI \u2014 Genetic Testing Fact Sheet
- NCI \u2014 BRCA Gene Changes: Cancer Risk and Genetic Testing
- AABB \u2014 DNA Relationship Testing FAQs
- AABB \u2014 Standards for Relationship Testing Laboratories
Considering PGT-M for your IVF cycle?
Speak with our reproductive genetics team for personalized counselling.