PGT-M Testing Errors

PGT-M lets families who carry a known gene variant test IVF embryos before transfer. Each test is custom-built for one family, often using DNA from relatives, so errors can start long before an embryo is biopsied. Some wrong results come from limits no lab can fully remove. Others come from mislabeled samples, a test built for the wrong variant or a report that was misread or never explained. A PGT-M attorney can help you find out which one happened.

How PGT-M testing works for a known family variant

PGT-M stands for preimplantation genetic testing for monogenic conditions. These are conditions caused by a variant in a single gene, such as cystic fibrosis, sickle cell disease or Huntington's disease5. PGT-M looks for a specific variant already known in your family. It can cover dominant, recessive and X-linked conditions2.

Unlike other embryo tests, PGT-M is built for each family. ASRM calls it the most complex form of PGT because it needs patient-specific counseling, confirmation of the variant, case review and a custom lab test, ideally before the IVF cycle starts1. The usual path looks like this:

• Genetic counseling about the condition and your options1
• A lab report confirming the exact gene and variant in your family1
• DNA samples, often cheek swabs, from you, your partner and relatives of known genetic status1
• Custom test development, which can take a few weeks to a few months1
• IVF, embryo biopsy and freezing while the samples are analyzed1
• A report for each embryo, followed by counseling about what it means1

Most labs track the variant two ways. Direct analysis looks for the variant itself. Linkage analysis follows nearby DNA markers that are inherited along with it, using family samples to learn which markers travel with the affected copy of the gene12. Running both lowers the risk that a missed copy of the gene leads to a wrong answer12.

PGT-M has other uses too. Some families use it to find an embryo that is a tissue match for a sick sibling. Others use it to test embryos for an adult-onset condition without learning their own genetic status1.

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

The three tests answer different questions, so their limits and their errors differ4:

• PGT-M checks for one known gene variant in your family. It does not count chromosomes unless PGT-A is added.
• PGT-A screens all chromosomes for extra or missing copies. It does not look for a family disease.
• PGT-SR checks for chromosome imbalances when a parent carries a structural rearrangement, such as a translocation.

PGT-A can often be run on the same biopsy as PGT-M. ASRM notes that adding it may leave fewer embryos to transfer, and that in young patients PGT-A has no proven benefit for live birth rates1.

Where PGT-M errors can happen

PGT-M passes through many hands over many months. A mistake at any step can lead to the wrong answer for an embryo. Problems can arise in:

• Test development: the wrong gene, variant or inheritance pattern used to design the test
• Family samples: a relative's sample mislabeled, or a relative's genetic status recorded wrong
• Sample identification: biopsy tubes swapped or labeled with the wrong embryo number (see sample mix-ups)
• Analysis: too few informative markers, or contamination that was not caught
• Interpretation: a recombination or dropout misread as a clear result
• Reporting: the wrong embryo marked unaffected, or confusing terms like carrier and affected
• Communication: limits, reduced accuracy or inconclusive results not explained to you

European guidance puts it plainly: results based on family markers are only as accurate as the samples. It says reports should state that accuracy assumes the samples were correctly identified, family relationships are true and relatives' diagnoses are correct3. The same guidance calls for two unique identifiers on each sample and an independent check at high-risk steps3.

Donor eggs or sperm add another step. ASRM says the lab always needs the donor's DNA for PGT-M, and that switching to a new donor means the test must be updated1. A missing donor sample or an outdated test is the kind of gap a PGT-M lawyer looks for.

Standards and guidance for PGT-M testing

In its 2023 committee opinion, ASRM noted that PGT-M is not regulated in the United States, unlike in other countries, and that the current lack of PGT-M-specific U.S. guidelines has led to differences between clinical and laboratory practices1. Professional guidance still sets clear expectations:

What professional guidance expects

Counseling first

Patients should have genetic counseling about the condition and all reproductive options before PGT-M. Accepting PGT-M should be optional1.

Clear limits

Pretest counseling should cover inconclusive or reduced-accuracy results and limits that can cause diagnostic error1. The work-up report should state test limits and residual risk2.

Known reporting terms

Labs use different words, such as carrier, affected, unaffected and wild type. Clinics should understand how their lab reports results1.

Inconclusive embryos

ESHRE does not recommend transferring PGT-M embryos with no result or an inconclusive result3.

After a misdiagnosis

The center should investigate the cause and change its protocols. Many causes are avoidable with good quality management3.

A family that does everything asked of it, from swabs to counseling, should get a result that was built and reported with the same care.

Where the law stands on PGT-M errors

Claims over PGT-M errors generally depend on state law, the contracts you signed and the facts of your case. State law also differs on claims tied to the birth of a child. Arizona, for example, says a person is not liable for damages in a civil action for wrongful birth or wrongful life, whether the child is born healthy or with a medical condition. That rule does not apply to intentional or grossly negligent acts or omissions6. Other states treat these claims differently, and legal treatment of embryos also varies by jurisdiction.

Because of these differences, an attorney reviewing a PGT-M lawsuit will look closely at where treatment and testing happened, which company did the analysis and what each party promised in writing.

What happens when an embryo is misclassified

An error can run in either direction, and each causes a different kind of harm:

• An affected embryo is reported as unaffected and transferred
• An unaffected embryo is reported as affected and discarded or never used (see embryos discarded after genetic testing)
• A pregnancy faces hard decisions after prenatal testing finds the condition
• A child is born with the condition the family worked to avoid
• The family repeats IVF, often with new test development costs
• Family secrets, such as unexpected parentage, coming to light through relatives' samples1
• Grief, guilt and strain on the family

The effects can surface at different times. Some families learn of a problem from a prenatal test. Others learn only after birth, or when a frozen embryo is retested years later. The records from each step, and when you learned of the problem, shape what a review can show.

Genetic counseling and confirmatory prenatal testing

Because of known technical limits, ASRM says prenatal testing should be offered for pregnancies after PGT-M to confirm the embryo result1. Chorionic villus sampling or amniocentesis can confirm a PGT-M result with higher accuracy during pregnancy1. ACOG also says a normal or negative embryo test does not ensure a baby without genetic problems4.

Choosing whether to have prenatal testing is a personal decision. ASRM notes these choices can be nuanced and shaped by emotion and how a family sees the risk1. Declining a prenatal test does not cause a lab error. If a test was designed, run or reported wrongly, that mistake belongs to the people who made it, not to the patient. Our page on PGT results and testing limitations explains residual risk across all types of embryo testing.

When to talk to a PGT-M attorney

Consider speaking with a lawyer if:

• Prenatal or newborn testing found the condition PGT-M was meant to screen out
• Records list the wrong variant, the wrong relative or the wrong embryo
• You were never told a result had reduced accuracy
• An embryo was transferred despite an inconclusive result you did not know about
• Retesting shows an embryo was misclassified

A claim review compares the test design with the confirmed family variant. It checks every sample's chain of custody, the lab's interpretation and the reports and counseling notes you received.

Who may be responsible for a PGT-M testing error

• The PGT laboratory that designed the test, analyzed samples and wrote the report
• The fertility clinic that ordered the test and chose embryos for transfer
• The embryology lab that performed the biopsy and labeled the tubes
• A genetic counselor or physician who explained, or failed to explain, the results
• A diagnostic lab that reported a family member's genetic status

None of these parties is presumed at fault. Their roles depend on the records and agreements in your case.

Filing deadlines for a PGT-M lawsuit

Each state sets its own deadlines. California, for example, generally requires a professional negligence suit against a health care provider to be filed within three years of the injury or one year after the injury was or should have been discovered, whichever comes first, with limited exceptions such as fraud or intentional concealment7. Some PGT-M errors are found only during pregnancy or after birth, so the timing of discovery can matter. Other states use different periods and add pre-suit steps. Talk with a lawyer promptly.

Tell Us Your Story →

Records that matter in a PGT-M review

Records to request or keep

Genetic testing records

• The original lab report confirming the family variant
• PGT-M case review and work-up report
• Embryo-by-embryo PGT-M results
• Any retest, prenatal or newborn genetic results

Family and sample records

• List of relatives who gave samples
• Sample collection kits and shipping records
• Donor DNA records, if donor eggs or sperm were used

Consent and care records

• PGT-M consent forms and lab requisitions
• Genetic counseling notes
• Embryo transfer and disposition records
• Messages and emails with the clinic or lab

What happens after you contact CBW Law

Our review process

1. Tell us your story

   Tell us the condition tested, when testing happened and what you have learned since.

2. We check deadlines

   We look at where care took place and whether a filing deadline may be near.

3. We study the testing trail

   With your permission, we gather lab, clinic and counseling records and follow each sample from swab to report.

4. We give you an honest answer

   We explain whether we see a claim and what it would involve. Contacting us does not mean we will take the case.

Plain English

Medical, Health & Insurance

PGT-M reports mix genetics, lab and billing language. These short definitions may help.

Genetics basics

Monogenic condition

A condition caused by a variant in a single gene5.

Autosomal recessive

A child is affected only with variants in both copies of the gene; parents are usually unaffected carriers5.

Autosomal dominant

One altered copy of the gene is enough to cause the condition5.

Variant of uncertain significance (VUS)

A gene change without enough evidence to call it harmful or harmless1.

PGT-M lab terms

Linkage analysis

Tracking DNA markers next to the gene that are inherited along with the variant1.

Allele dropout (ADO)

Failure to detect one of the two gene copies in a small sample2.

Recombination

An exchange of DNA between paired chromosomes that can separate a marker from the variant2.

Haplotype

A group of DNA markers on one chromosome inherited together2.

Pregnancy testing

Chorionic villus sampling (CVS)

A prenatal diagnostic test of placental tissue that can confirm a PGT-M result1.

Amniocentesis

A prenatal diagnostic test of fluid around the fetus that can confirm a PGT-M result1.

Insurance and billing

Test development fee

A charge for building a family-specific PGT-M test before embryos are tested.

Prior authorization

An insurer's approval needed before some services are covered.

Explanation of benefits (EOB)

An insurer's statement of what was billed, paid and owed.

Questions

Frequently asked PGT-M testing error questions

Answers to common questions from families who used PGT-M.

What is PGT-M, in simple terms?

PGT-M is a test of a few cells from an IVF embryo for one gene variant known to run in your family. It is used for single-gene conditions with dominant, recessive or X-linked inheritance2. The lab builds a custom test for your family before the embryos are tested1.

Why did the lab need DNA from my relatives?

Many PGT-M tests track markers near the gene that are passed down with it. Samples from relatives of known genetic status show which markers travel with the affected copy1. If a relative's sample is mislabeled or their status is recorded wrong, the test can be built on a false map3.

What is allele dropout?

Allele dropout happens when one of the two copies of a gene in a tiny biopsy sample fails to amplify and goes undetected2. It can make an affected embryo look unaffected. Labs reduce this risk by also tracking linked markers1. Dropout is a known limit of the test, so whether it points to an error depends on how the lab designed and checked the test.

My child was born with the condition after PGT-M. Does that mean someone was negligent?

Not by itself. PGT-M has a residual risk even when done correctly, and ACOG says a normal embryo result does not ensure a child without genetic problems4. A review looks for preventable causes, such as a sample mix-up, a test built for the wrong variant or a reporting mistake.

I declined prenatal testing. Does that hurt my claim?

Prenatal testing is offered to confirm PGT-M results, but it is a personal choice1. Declining it does not cause a lab or reporting error. How the law treats that choice can vary by state, so it is a question to raise with a lawyer rather than a reason to stay silent.

What does an inconclusive PGT-M result mean?

It means the lab could not reliably say whether the embryo has the variant. Causes include allele dropout, poor DNA quality, contamination or recombination1. A rebiopsy often yields a result, but not when recombination is the cause1. ESHRE does not recommend transferring PGT-M embryos with an inconclusive result3.

Can PGT-M results be transferred to another lab?

Usually not. ASRM says test development is lab-specific, so switching labs means building the test again, and leftover biopsy DNA typically cannot be moved between labs1. If you changed labs or donors, ask whether the test was updated. ASRM says a new donor requires an updated test1.

Who can be sued for a PGT-M testing error?

It depends on who made the mistake. Possible parties include the PGT lab, the fertility clinic, the embryology lab, the genetic counselor or physician, and a diagnostic lab that tested a relative. No one is presumed responsible. A PGT-M lawyer starts with the records to see where the chain broke.

How long do I have to bring a PGT-M lawsuit?

It depends on your state. In California, for example, many claims against health care providers must be filed within three years of injury or one year after discovery, whichever is first7. Other states differ, and some require notice before filing. Contact an attorney soon after you learn of a possible error.

Tell Us Your Story

PGT-M depends on a long chain of family samples, custom lab work and careful reporting. When a link in that chain breaks, the result can change a family's life.

If a PGT-M result did not hold up, tell us your story. We will look at what happened and explain your options honestly, without promising a particular outcome.

Tell Us Your Story →Call (800) 476-2416

This page is general information about PGT-M testing errors. It is not legal or medical advice and does not create an attorney-client relationship. An unsuccessful cycle, a complication, an embryo loss or a testing limitation does not, by itself, establish that anyone was negligent. No outcome can be promised in any case.