Short answer: Preimplantation genetic testing for monogenic conditions, called PGT-M, may be considered when a person or couple has a known inherited condition caused by a change in a specific gene. Embryos created through IVF can be tested for the family-specific condition before a transfer decision is made. The process requires genetic counseling, confirmation of the familial variant, laboratory planning, and informed discussion of limitations.
PGT-M is not a general screening test for every health condition and it cannot guarantee pregnancy or a child without every possible medical problem. It answers a focused question about a known gene-related condition. Families should understand what is being tested, what is not being tested, and whether prenatal confirmation may still be recommended after pregnancy.
When may PGT-M be discussed?
PGT-M may be relevant when one or both genetic parents carry a pathogenic variant associated with an autosomal dominant, autosomal recessive, or X-linked condition. Examples can include cystic fibrosis, thalassemia, sickle cell disease, spinal muscular atrophy, or another confirmed family-specific disorder. The inheritance pattern changes the expected chance that an embryo is affected or carries the condition.
A family history alone may not be enough to start testing. The genetics team usually needs the exact laboratory report identifying the relevant variant. Sometimes samples or records from relatives are useful for test development. If the genetic finding is uncertain, the team may recommend more evaluation before an IVF cycle is planned.
How does the process work?
The first step is genetic counseling and review of the family report. A specialized laboratory then determines whether a reliable family-specific PGT-M test can be developed. This preparation can take time and should generally happen before ovarian stimulation begins. The couple should receive an explanation of accuracy, possible inconclusive results, allele dropout, contamination controls, and whether additional chromosome testing is being considered.
After IVF and embryo culture, a small number of cells may be biopsied from a blastocyst. The embryo is usually frozen while the laboratory analyzes the sample. Results may classify embryos according to the condition being tested, but the exact reporting categories depend on the inheritance pattern and laboratory. The embryo biopsy guide gives a broader overview of this step.
What PGT-M can and cannot tell you
PGT-M can provide information about the specific familial condition for which the test was designed. It does not exclude all genetic, chromosome, developmental, or pregnancy risks. A result may occasionally be inconclusive or unsuitable for interpretation, and not every embryo will reach the stage needed for biopsy.
Embryo morphology and PGT-M answer different questions. A visually favorable embryo can carry the familial variant, and an embryo without that variant may have other factors affecting transfer potential. Patients can review the embryo grading guide to understand this difference. Decisions should combine the genetic result, embryology report, medical history, and transfer plan.
Why genetic counseling matters
Counseling should cover the inheritance pattern, the chance of affected or carrier embryos, the possibility that no embryo is available for transfer, alternatives to PGT-M, and the emotional and financial impact of multiple IVF cycles. It should also explain whether prenatal diagnostic testing such as chorionic villus sampling or amniocentesis may be recommended to confirm the result during pregnancy.
Patients should ask how data and samples are stored, who receives the report, how long test development takes, and what happens if a result is inconclusive. International treatment adds logistical questions about transporting samples, coordinating the genetics laboratory, travel timing, and follow-up after returning home.
Questions to ask before starting
- What exact gene and variant will the test target?
- What is the inheritance pattern and expected embryo risk?
- Does the laboratory need samples from relatives?
- How long will family-specific test development take?
- What are the possible result categories?
- Will prenatal confirmation still be recommended?
FAQ
Is PGT-M the same as chromosome screening?
No. PGT-M targets a specific single-gene condition. Other forms of testing may examine chromosome number or structural rearrangements and have different indications and limitations.
Can PGT-M guarantee an unaffected baby?
No medical test offers an absolute guarantee. PGT-M can substantially inform embryo selection for the targeted condition, but limitations and confirmation options must be discussed.
Can testing begin without a confirmed family variant?
Usually the exact genetic finding is needed. A genetics professional can review whether additional family testing is required.
Next step
Prepare the original genetic laboratory reports and family history before requesting treatment. You can contact IVF Turkey to ask whether a coordinated fertility and genetics review is appropriate for your case.