PGT-M for Single Gene Disorders in Thailand: A Patient Guide

What Is PGT-M?

Preimplantation genetic testing for monogenic disorders (PGT-M) is a technique used during in vitro fertilization (IVF) to identify embryos that carry a specific single-gene disorder. It is designed for couples or individuals who have a known genetic condition and wish to reduce the chance of passing it to their children. PGT-M is not a guarantee of a healthy pregnancy or live birth, and it is not suitable for everyone. The decision to use PGT-M should be made in consultation with a genetic counselor and fertility specialist.

How PGT-M Differs from PGT-A and PGT-SR

PGT-M is one of three main types of preimplantation genetic testing:

• PGT-A (aneuploidy testing) screens embryos for abnormal numbers of chromosomes (e.g., extra or missing chromosomes). It is often used to improve implantation rates and reduce miscarriage risk, especially in older women.
• PGT-SR (structural rearrangement testing) detects embryos with unbalanced chromosomal rearrangements, such as translocations or inversions, which can cause infertility or miscarriage.
• PGT-M specifically looks for a single gene mutation that causes a specific inherited disorder, such as cystic fibrosis, sickle cell disease, or Huntington’s disease. It requires prior knowledge of the exact mutation in the family.

Each test has different indications, limitations, and success rates. Your clinic will help determine which test, if any, is appropriate for your situation.

The PGT-M Process in Thailand

1. Genetic Counseling and Testing

Before starting IVF with PGT-M, you and your partner (if applicable) will undergo genetic counseling and testing to confirm the specific mutation. This may involve blood or saliva samples from affected family members. The results are used to design a personalized test for your embryos.

2. Probe Development

A crucial step in PGT-M is creating a genetic probe—a custom laboratory tool that can identify the mutation in embryonic cells. This process, called probe development or assay design, typically takes several weeks. The probe is made using DNA from the family (e.g., from the parents and an affected child or other relatives). In Thailand, experienced genetic laboratories can develop probes for a wide range of single-gene disorders. The time required and cost of probe development vary by clinic and the complexity of the mutation. You should ask your clinic for an estimate of the timeline and fees.

3. IVF and Embryo Biopsy

Once the probe is ready, you undergo a standard IVF cycle to retrieve eggs and create embryos. On day 5 or 6 of development, a few cells are gently removed from each embryo (biopsy). These cells are sent to the genetics lab for analysis.

4. Genetic Analysis

The lab uses the custom probe to test the biopsied cells for the mutation. Results typically take a few days to a week. Embryos are classified as unaffected (no mutation), affected (carrying the mutation), or inconclusive. Only unaffected embryos are considered for transfer.

5. Embryo Transfer and Follow-Up

One or more unaffected embryos are transferred to the uterus. Any remaining unaffected embryos may be frozen for future use. After pregnancy is confirmed, prenatal diagnostic testing (e.g., chorionic villus sampling or amniocentesis) is recommended to confirm the PGT-M result, as embryo testing is not 100% accurate.

What Conditions Can Be Tested?

Thailand’s genetic laboratories can develop probes for many single-gene disorders, including autosomal dominant, autosomal recessive, and X-linked conditions. Common examples include cystic fibrosis, spinal muscular atrophy, beta-thalassemia, and Huntington’s disease. However, not all disorders are testable; the mutation must be known and the family must provide sufficient DNA samples. Your clinic can advise on whether your specific condition is eligible for PGT-M.

Costs and Timeline

The cost of PGT-M in Thailand includes several components: probe development, IVF cycle, embryo biopsy, genetic testing, and embryo transfer. Probe development is a one-time fee that can range from a few hundred to several thousand US dollars, depending on the complexity. The total cost for a full PGT-M cycle is typically higher than standard IVF. Exact prices vary widely between clinics and are subject to change. You should request a detailed cost breakdown from your chosen clinic.

The timeline from initial consultation to embryo transfer can take several months. Probe development alone may take 4–8 weeks. IVF stimulation and egg retrieval add another 2–3 weeks, followed by biopsy and testing (1–2 weeks). Planning ahead is essential.

Alternatives to PGT-M

PGT-M is not the only option for couples at risk of passing on a genetic disorder. Alternatives include:

• Prenatal diagnosis (e.g., CVS or amniocentesis) during pregnancy, with the option to terminate an affected pregnancy.
• Donor gametes (egg or sperm) from a donor without the genetic condition.
• Preimplantation genetic testing using polar body biopsy (less common).
• Natural conception with no testing, accepting the risk.

Each option has medical, ethical, and emotional implications. Genetic counseling can help you weigh the choices.

Limitations and Risks

• Not 100% accurate: There is a small chance of misdiagnosis due to technical errors or biological factors (e.g., mosaicism). Confirmatory prenatal testing is strongly advised.
• No guarantee of pregnancy: PGT-M does not improve the chance of implantation or live birth; it only selects against a specific mutation.
• Embryo loss: Some embryos may be affected or inconclusive, reducing the number available for transfer.
• Time and cost: The process is lengthy and expensive, and not all clinics offer PGT-M.
• Ethical considerations: Some individuals or cultures may have concerns about embryo selection.

Choosing a Clinic in Thailand

When considering PGT-M in Thailand, look for a clinic with:

• Experience in PGT-M and a dedicated genetics laboratory.
• Clear communication about probe development timelines and costs.
• Genetic counseling services.
• Transparent success rates (though these are not directly comparable).

You can find more information on our PGT in Thailand page, guides, and FAQ.

Frequently Asked Questions

Frequently asked questions

How long does probe development take for PGT-M?

Probe development typically takes several weeks, often 4–8 weeks, depending on the complexity of the mutation and the laboratory's workload. Your clinic can provide a specific timeline.

Can PGT-M test for any single gene disorder?

PGT-M can test for many single-gene disorders, but the specific mutation must be known and the family must provide adequate DNA samples. Some rare or complex mutations may not be testable. Consult your clinic for eligibility.

Is PGT-M covered by insurance in Thailand?

Insurance coverage for PGT-M varies. Most international patients pay out-of-pocket. Check with your insurance provider and clinic for details.

What is the success rate of PGT-M?

Success rates depend on many factors, including maternal age, embryo quality, and the specific genetic condition. PGT-M does not guarantee a live birth. Ask your clinic for their most recent data.

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.