1. The "30-year-old problem" of third-generation IVF

PGT-M, a technique used in third-generation IVF, is a crucial method for couples with genetic disorders to have healthy children. The principle behind this technique is to extract a small sample of trophoblast cells before embryo transfer for genetic testing. This allows us to determine whether the embryo carries pathogenic mutations inherited from both parents. Only healthy embryos are transferred.

Since its introduction into clinical practice in the 1990s, this technology has helped countless families around the world. However, traditional PGT-M relies on DNA testing, and there are three major challenges that have plagued the industry for over thirty years:

Challenge 1: High failure rate of amplification

Each gene in a single cell has only two copies (one from each parent). Therefore, the amount of DNA available is very limited, and whole-genome amplification (WGA) must be performed first. Approximately 10% of samples fail during the amplification process or become contaminated, rendering the entire test ineffective. This means that one out of every ten embryos is wasted due to technical issues.

Challenge 2: Deletion of alleles

In about 20% of cases, alleles are deleted during amplification. This means that only one copy of the gene is amplified, while the other is lost. This can lead to the misidentification of diseased embryos as normal, resulting in the wrong embryos being transferred into the uterus.

Challenge 3: Inability to detect certain genes

Some genes are located in DNA regions with extremely high GC content. During amplification, these regions may get stuck, making it impossible to detect the gene. For example, the ATXN3 gene responsible for Spinocerebellar Ataxia Type 3 cannot be detected using traditional DNA testing.

What's more important is that traditional PGT-M can only determine whether there is a genetic disorder. It cannot predict whether an embryo will successfully implant. Even if healthy embryos are selected, they don't necessarily have high implantation potential. As a result, the overall live birth rate doesn't improve significantly.

"line-height: 2.5;">II. Core Innovations: From 'Static ID Cards' to 'Real-time Work Logs'

Academician Qiao Jie's team proposed a clever approach: switching the object of detection from DNA to RNA.

DNA serves as the "static design blueprint" of the human body. Each gene has only two copies within a single cell, which is a small amount and requires extensive amplification. If anything goes wrong, the entire system becomes invalid. In contrast, RNA represents the "work instructions" that cells execute. An active gene can produce hundreds of RNA copies, providing strong signals and sufficient quantities. Even if some copies are lost, it still allows for accurate analysis.

What's even better is that the trophoblast layer of the embryo itself plays a crucial role in communicating with the endometrium and facilitating embryo implantation. The RNA state of this layer acts as a mirror of the embryo's vitality. In theory, one cell sample can answer two questions simultaneously: does it contain pathogenic mutations? Does it have the potential to implant? This is the essence of this research.

III. Simulation and Verification: A 'Technical Test' with 19 Blastocysts

The team obtained 19 donated blastocysts from 20 couples. They analyzed RNA sequencing data using three groups of trophoblast cells-one, three, and five cells each. The results were as follows:

Stability: Even fewer samples are needed

Out of 57 samples, 94.7% (54 out of 57) expressed over 5,000 genes. Whether only one, three, or five cells were used, gene expression levels remained relatively stable. This means that less cells need to be sampled, resulting in less damage to the embryo.

Coverage: 2,814 out of 4,868 genetic diseases-related genes were expressed

Out of the 4,868 single-gene genetic disease-related genes recorded in the OMIM database, 2,814 were expressed in trophoblast cells. Among the 527 genes commonly used in PGT procedures...

In the genes, 162 are highly expressed, making them suitable for direct detection of mutations using RNA.

Disruptive findings: 91 "selected genes"

The team identified 91 genes that were undetectable using traditional DNA testing methods-these genes are extremely difficult to diagnose accurately, which can lead to misdiagnosis. However, in RNA testing, these genes show high expression levels and stable signals, indicating their effectiveness. These 91 genes represent the most critical areas where the new method can provide accurate results, areas that traditional methods cannot reach at all.

IV. Real-world applications: 26 families, 82 embryos

The team recruited 26 families with various single-gene disorders. These families suffered from 18 different single-gene diseases, involving 22 different pathogenic genes. In total, 82 blastocysts were obtained. Each blastocyst was sampled using both the new RNA-based method and the traditional DNA-based method for comparison.

significant.

Detection method	Success rate	Accuracy	Description
Direct mutation detection	90% (100/111 times)	95%	Directly identifies pathogenic mutations
Linkage analysis	95% (76/80 times)	100%	Indirect determination through adjacent genetic markers, with no errors.
82 blastocysts were screened for suitability. 48 are healthy embryos.	-	The number of embryos that can be used for transplantation is quite...

Breakthroughs: DNAera's solution to the genetic disease problem "Unable to resolve the issue"

What's most exciting is that this new approach has successfully solved those problems that were difficult to address using traditional methods.

methods.DNAIt is not possible to detect those difficult-to-cover genetic issues during the analysis.

Spinocerebellar Ataxia3Type/FormSCA3):ATXN3geneticCAGRepetitive regionsGCThe content is extremely high; traditional indeed.DNAcannot be identified. The research team usedRNAThe method involves directly detecting the product. It has been successfully implemented.3 SCA3It has been confirmed in the patient's embryos.CAGNumber of repetitions--This is the first time such a method has been used internationally.RNAmethod for CAGReports on embryo screening for patients with recurrent dilation disorders.

ADAGene (Severe Combined Immunodeficiency Disease),ALPLGenes Such as hypophosphatemia deficiency: Traditional DNA methods cannot cover all these areas. RNA-based methods can also achieve accurate diagnosis.

Clinical outcomes

In this family, there are 15 members in total. The embryo was successfully transplanted.

In this family, a total of 15 embryos were transplanted back into the uterus. Six of them have successfully implanted. Four families have successfully given birth to healthy newborns. There are also four pregnant women in this group. Occasionally, amniocentesis was performed for prenatal diagnosis. The results were as follows: The results of the tests are completely consistent, which further proves the reliability of this new method.

Consistent results further prove the reliability of this new method.

The most significant breakthrough: The accuracy of embryo implantation prediction has reached 78.6%

This technology represents a groundbreaking innovation. compared to traditional detection methods. It can predict the implantation potential of embryos-something that can be useful for all types of in vitro fertilization procedures.

The team's prediction model is straightforward in its logic: it calculates the relative expression levels of genes on each chromosome, identifies any abnormalities in gene expression, and computes the overall gene expression level. Research has found that embryos with failed implantation often exhibit excessively high overall gene expression levels.

Prediction Dimension	Accuracy	Explanation
Overall Implantation Prediction	78.6% (11/14)	Out of 14 embryos with complete records, 11 were correctly predicted
Prediction of Transplant Failure	87.5% (7/8)	Out of the 8 embryos predicted to fail, 7 did fail
Prediction of Successful Transplantation	66.7% (4/6)	Out of the 6 embryos predicted to succeed, 4 actually implanted successfully

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New technologies are significantly better at predicting "failure" than "success". This is completely reasonable in the medical field: for an embryo to successfully implant, both the embryo's own health and the conditions in the uterus must be suitable. If any one of these factors fails, the implantation will not occur. In contrast, predicting failure only requires identifying any issues with the embryo itself. Therefore, RNA technology can effectively help us eliminate most embryos that are unlikely to implant.

Surprising discovery: genes responsible for embryo apoptosis

The research team also compared the RNA sequences of successful and failed embryos and identified 31 genes that were highly correlated. Of these, 28 genes were overactive in the group of failed embryos. Four key genes involved in apoptosis-RIPK1, USP15, SMAD4, and SH3RF1-were excessively activated in failed embryos, meaning that apoptosis began even before implantation. These four genes could potentially become markers for assessing embryo quality in the future.

VI. DNA vs RNA: Why the new method is more sensitive?

Comparison dimension	Traditional DNA-PGT-M	RNA-PGT-M (new method)
Objects of analysis	Static genomic information (2 copies of each gene)	Gene activity data (hundreds to thousands of mRNA copies per gene)
Is amplification necessary?	WGA whole-genome amplification is required; it's unstable	="1" width="25.0000%">No need for invasive amplification; natural signals are strong.
Failure rate of amplification	Approximately 10% of samples are discarded.	Generally not affected.
Allele loss	Approximately 20% of genes have lost copies.	With numerous copies, occasional losses do not affect the outcome.
Coverage of problematic genes	91 genes have zero coverage, making diagnosis impossible.	All 91 genes were accurately detected.
Implantation prediction	Unable to predict.	Overall accuracy: 78.6%; failed predictions: 87.5%.
Accuracy of linkage analysis	There is a risk of misjudgment due to errors in detection.	100% (76/76, zero errors).

VII. Significance for the international IVF industry

This breakthrough achievement by the team led by Academician Qiao Jie has significant implications for the assisted reproduction industry:

1. Embryo screeningChoose the upgrade from "Only Disease Detection" to "Disease Detection + Vitality Assessment". For thirty years, PGT-M has only been used to address issues related to genetic diseases. This new method makesimplantation prediction possible, and is expected to significantly improve the survival rate of successful transplants.

2. Families with complex genetic diseases now have hope again. For 91 genes that cannot be detected by traditional methods, this new method enables accurate diagnosis. Genetic diseases such as SCA3, which were previously impossible to diagnose, can now be screened at the embryo level for the first time.

3. Reduces the number of ineffective transplants, thereby reducing the physical and emotional burden on patients. An accuracy rate of 87.5% means that most embryos that are unlikely to implant can be eliminated before transplantation, avoiding the time, cost, and emotional strain associated with ineffective transplants.

4. Promotes the standardization of PGT technology. This research provides a new approach for international reproductive medicine professionals, along with new directions for research on markers of apoptosis. It helps to move assisted reproductive technology from being based on experience to being based on evidence-based standards.

Leilawa International Assisted Reproduction continues to pay attention to the latest advancements in assisted reproduction technologies. Currently, this technology is still in the research stage, and its widespread clinical application requires further large-scale validation. The PGT-A/PGT-M testing methods used by overseas reproductive hospitals that work with Leilawa are determined by the reproductive doctors who treat patients, based on the specific circumstances of each patient. Leilawa International Assisted Reproduction helps clients find qualified hospitals and experts, and coordinates the entire process of cross-border medical treatment. We do not participate in the development of medical plans.

VIII. Overview of Key Data

Indicator	Data
Accuracy of Direct Mutation Detection	95%	There is a risk of misjudgment.
Accuracy of chain analysis	100%	It's impossible to guarantee zero mistakes.
Overall accuracy of implantation prediction	78.6%	Completely unpredictable
Accuracy of failure prediction	87.5%	Impossible to predict
Coverage of problematic genes	91The gene was accurately detected.	Coverage: 0There is no detection range at all.
Clinical validation results	4A healthy baby was born, and the results of the amniocentesis are as follows:100%Consistency	-
Sample utilization rate	94.7% of samples are available	Approximately 10% of samples experienced amplification failures

This study was published in "Advanced ScienceThe research findings published in the journal were developed by Academician Qiao Jie's team. These solutions represent original Chinese contributions to the field of assisted reproduction worldwide. It is hoped that this technology can be quickly validated through large-scale clinical trials and widely utilized, thereby helping more families with single-gene genetic disorders avoid unnecessary troubles and enabling them to have healthy babies as soon as possible.