What it is
For people who know they are at increased risk of passing on a specific genetic condition, PGT-M, or preimplantation genetic testing for monogenic/single gene defects, can be performed prior to pregnancy to greatly reduce the risk of having an affected child. PGT-M for single gene disorders involves testing embryos created through in vitro fertilization (IVF) and then transferring unaffected embryos. PGT-M was formerly known as PGD, preimplantation genetic diagnosis.
WHO IT’S FOR
PGT-M is appropriate for people who are at high-risk of passing on a specific single gene disorder. You may consider PGT-M if:
- You and your partner are carriers of the same autosomal recessive condition (e.g. Cystic fibrosis)
- You are a carrier of an X-linked condition (e.g. Duchenne Muscular Dystrophy)
- You or your partner have an autosomal dominant condition (e.g. Huntington disease)
- You or your partner have a mutation associated with a hereditary cancer syndrome (e.g. BRCA1 & 2)
- You had a child or pregnancy with a single gene disorder
- You want to perform HLA matching
How it works
PGT-M tests are created uniquely for each family. PGT-M can be performed for nearly any single gene disorder as long as the specific familial mutation has been identified and appropriate family members are available for test preparation.
*Internal CooperGenomics data
The PGT-M Process
1. Case Review
Prospective parents speak with a genetic counselor and discuss if additional genetic testing of the couple or other family members is required.
2. PGT-M Test Preparation
The PGT-M lab designs a test unique to each family.
In vitro fertilization is performed and the resulting embryos are incubated.
4. Embryo Biopsy
An embryologist carefully removes a small cell sample from each embryo.
Samples are sent to the PGT-M laboratory, testing is performed, and results are released to the IVF center.
6. Embryo Transfer
An unaffected embryo is transferred. Remaining embryos can be frozen for future use.
PGT-M testing involves a close examination of both the mutation an individual carries and the area of the chromosome surrounding it, shown above as the colored segment of each chromosome. Each PGT-M test design is unique and specific to the family, so DNA samples from both partners, and often additional family members, will be requested in order to design a test. Then, linkage analysis is used to determine the “genetic fingerprint” of the mutation and diagnose each tested embryo as affected or unaffected.