PGT-M in Thailand: A Practical Workflow Guide for Carriers of Single Gene Disorders

PGT-M (preimplantation genetic testing for monogenic disorders) is an IVF add-on that aims to identify embryos affected by a specific inherited single gene disorder before transfer. In Thailand, the practical workflow usually involves four stages: genetic counseling and test design, building and validating a family-specific probe, an IVF cycle with embryo biopsy, and genetic analysis of the biopsied cells. PGT-M is not a guarantee of a healthy child, and it is not suitable or necessary for every couple. It is one option among several, and its value depends on your specific gene variant, family history, and reproductive goals.

At a glance

• PGT-M is designed for a known single gene disorder in the family, not for general screening.
• It requires a custom laboratory test (a probe or assay) built around your family’s specific variant.
• Probe development and validation usually happen before the IVF cycle starts.
• PGT-M does not replace prenatal testing or guarantee a particular outcome.
• Timelines, costs, and legal details vary and must be confirmed directly with your clinic and relevant authorities.

What PGT-M is and is not

PGT-M looks for a specific, already-identified genetic change. It is different from PGT-A, which counts chromosomes to look for numerical abnormalities, and from PGT-SR, which is used when there is a known structural chromosome rearrangement. PGT-M is targeted: the laboratory is not scanning the whole genome for every possible problem. It is checking whether each embryo has inherited the particular variant that runs in your family.

Because of that, PGT-M cannot rule out all genetic conditions. It does not detect new (de novo) changes that were not part of the original test design, and it does not guarantee a pregnancy, a live birth, or a child without health issues. It also does not replace diagnostic testing during pregnancy if that is recommended by your doctor.

Who typically considers PGT-M

PGT-M is usually discussed when at least one partner is a known carrier of a single gene disorder, or when a couple has a child or family history affected by a condition with a known genetic cause. Common categories include autosomal recessive conditions (where both partners may be carriers), autosomal dominant conditions (where one partner is affected or carries the variant), and X-linked conditions.

Whether PGT-M is appropriate for you depends on the specific condition, the variant, the inheritance pattern, and your personal circumstances. This is a clinical and genetic counseling decision, not something to determine from a website alone.

The PGT-M workflow, step by step

Step 1: Genetic counseling and confirmation of the variant

The process usually begins with genetic counseling. A counselor or clinical geneticist reviews your family history, confirms the exact gene and variant involved, and explains inheritance patterns and reproductive options. If the variant has not been confirmed in your family, testing may be needed first. Without a confirmed variant, a PGT-M probe generally cannot be designed.

This stage is also where alternatives are discussed, which may include accepting the natural chance, using donor gametes, prenatal diagnosis, or choosing not to pursue PGT-M. These are personal decisions, and counseling is meant to support informed choice rather than push one path.

Step 2: Probe design and development

A PGT-M test is custom-built. The laboratory designs a probe (also called an assay) that can detect your family’s specific variant in a small number of cells taken from an embryo. Because embryo biopsy yields very little DNA, the test often uses linked genetic markers around the gene to improve reliability. This is sometimes called haplotyping.

Probe development can take time, and it may require DNA samples from family members, such as both partners and sometimes an affected or unaffected relative. The laboratory needs enough informative markers to distinguish affected from unaffected embryos. If family samples are limited, the process can be more complex or, in some cases, not feasible.

Step 3: Probe validation

Before clinical use, the probe is validated. Validation checks that the test performs reliably on the relevant DNA and that it can correctly identify the variant and linked markers. Some laboratories also use a reference sample or a previously affected pregnancy sample to confirm accuracy. Validation is a quality step, not a guarantee of a successful pregnancy.

Step 4: IVF cycle and embryo biopsy

Once the probe is ready, an IVF cycle is planned. Eggs are retrieved and fertilized, and embryos are cultured. At a suitable stage, typically day 5 or day 6, a few cells are biopsied from each embryo. The biopsied cells are sent for genetic analysis, and the embryos are usually frozen while results are pending.

Step 5: Genetic analysis and results

The laboratory analyzes the biopsied cells using the validated probe. Results are typically reported as affected, unaffected, or carrier (for recessive conditions), depending on the inheritance pattern and the test design. Some embryos may have no result or an inconclusive result. Your clinic and genetic counselor should explain what each result means for your family and what the limitations are.

Step 6: Transfer and follow-up

Embryos identified as unaffected (or, in some cases, carriers) may be considered for transfer. Transfer decisions are clinical and personal. Even after PGT-M, your doctor may recommend confirmatory testing during pregnancy, because no test is perfect. Follow-up care and genetic counseling remain part of the process.

Timeline: what to expect

PGT-M timelines vary widely depending on the condition, the laboratory’s workload, and whether family samples are available. As a general orientation, the workflow often includes:

Stage	What happens	Typical considerations
Genetic counseling	Confirm variant, discuss options	May require records or additional testing
Probe design	Laboratory builds a custom assay	Depends on variant and family samples
Validation	Test performance is checked	Adds time before the IVF cycle
IVF cycle	Stimulation, retrieval, fertilization, biopsy	Standard IVF timeline applies
Analysis	Biopsied cells are tested	Results may take days to weeks
Transfer	Embryo transfer and follow-up	Depends on results and clinical advice

Exact durations are not fixed and should be confirmed with your clinic. Some laboratories can begin probe work while you prepare for IVF, but this depends on the provider.

Laboratory capability in Thailand

Thailand has a number of IVF laboratories, and some offer PGT-M. Capability varies by laboratory, including experience with specific conditions, access to family samples, and the genetic analysis platforms used. There is no single national standard that applies to every clinic, and not every laboratory can build a probe for every condition.

When researching, ask whether the laboratory performs PGT-M in-house or sends samples abroad, how many PGT-M cases they handle, and whether they have experience with your specific gene and variant. These are reasonable questions, and a transparent clinic should be able to answer them.

Questions to ask a clinic

• Do you offer PGT-M for my specific gene and variant?
• Is the probe built in your laboratory or sent to another facility?
• What family samples do you need, and what if they are not available?
• How long does probe development and validation usually take?
• What are the possible results, and what does an inconclusive result mean?
• What are the limitations of PGT-M for my condition?
• What are the costs, and what is included or excluded?
• What are the legal and regulatory requirements for treatment in Thailand?
• Do you provide genetic counseling, and who will explain the results?
• What follow-up testing do you recommend during pregnancy?

Limitations and alternatives

PGT-M has limitations. It cannot detect all genetic conditions, it may not be possible if the variant is not confirmed or if family samples are insufficient, and it does not guarantee a healthy child. Some embryos may be mosaic or have no result. The test is also not a substitute for prenatal diagnosis.

Alternatives include natural conception with or without prenatal testing, donor gametes, adoption, or choosing not to pursue testing. These options have different implications, and genetic counseling can help you weigh them.

Next steps

1. Gather your genetic test reports and family history details.
2. Speak with a genetic counselor or clinical geneticist about your specific variant.
3. Ask clinics about their PGT-M experience and laboratory arrangements.
4. Confirm timelines, costs, and legal requirements directly.
5. Consider how you would use each possible result before starting.

For more general information, see our PGT in Thailand overview and guides. You can also check our FAQ for common questions.

Frequently asked questions

What is the difference between PGT-M and PGT-A?

PGT-M looks for a specific single gene disorder that is known to run in your family. PGT-A counts chromosomes to look for numerical abnormalities, such as an extra or missing chromosome. They are different tests with different purposes, and some patients may be offered one or both depending on their situation.

How long does the PGT-M process take in Thailand?

Timelines vary widely. Probe development and validation can take weeks or longer, and the IVF cycle itself follows a standard timeline. The total duration depends on your specific variant, the laboratory's workload, and whether family samples are available. Your clinic can give you a more specific estimate after reviewing your case.

Can PGT-M guarantee a healthy baby?

No. PGT-M reduces the chance of transferring an embryo affected by the specific condition being tested, but it cannot guarantee a pregnancy, a live birth, or a child without health issues. It does not detect all genetic conditions, and confirmatory testing during pregnancy may still be recommended.

What if I don't have family samples for probe development?

Family samples, especially from both partners and sometimes a relative, can help the laboratory build a more reliable probe. If samples are limited, probe development may be more complex or, in some cases, not feasible. A genetic counselor or laboratory can explain your options.

Is PGT-M available for all single gene disorders in Thailand?

Not necessarily. Laboratory capability varies, and not every laboratory can build a probe for every condition. You will need to ask clinics directly whether they have experience with your specific gene and variant, and whether they perform the test in-house or send samples elsewhere.

Continue your research

• PGT in Thailand overview
• PGT and IVF guides
• Frequently asked questions

Medical information notice: This article is educational and does not replace individual assessment, diagnosis, genetic counselling or treatment advice from a licensed clinician. Provider services, availability, fees and policies should be verified directly before booking.