In most people's perceptions, rare diseases seem to be far from ordinary families. However, facts reveal that more than 80% of rare diseases stem from genetic factors. Many seemingly healthy couples may actually be carriers of recessive disease-causing genes, and they face the potential risk of having sick children.

Entering 2026, assisted reproductive technology has ushered in a new round of leap. The embryo gene screening system has been comprehensively upgraded, and the number of screening for rare diseases has increased significantly. With the help of the third-generation IVF PGT technology, we can conduct more comprehensive eugenics screening before pregnancy, block the transmission of hereditary rare diseases from the source, and provide more accurate and safe fertility strategies for families who are at high risk.

1. What does the upgrade of gene screening for rare diseases in vitro mean?

Test tube PGT gene screening mainly covers three major areas: chromosome screening, structural abnormality screening, and single-gene rare disease screening. In the past, clinical screening mainly focused on a few high-risk genetic diseases such as thalassemia, SMA, and hemophilia. However, since the technological innovation in 2026, the landscape of rare disease screening has expanded significantly, with hundreds of serious single-gene rare diseases added, such as hereditary deafness, albinism, hereditary metabolic diseases, and hereditary nervous system diseases.

In short, in the past, we could only detect a few common genetic diseases, but now we are able to conduct extensive screening covering a variety of complex and rare genetic diseases, greatly improving the accuracy of eugenics.

2. Which families are suitable for the upgraded screening for rare diseases?

In my country, embryo genetic screening has strict medical standards and is not carried out arbitrarily. Only families who meet the following conditions can apply for screening:

1. Both husband and wife or one of them carries a rare disease-causing gene

2. Had given birth to a child with rare diseases

3. A history of genetic diseases in the family

4. Both husband and wife are carriers of the same recessive genetic disease

5. Families with genetic high-risk conditions such as repeated fetal arrest and repeated biochemistry.

For ordinary and healthy couples planning for pregnancy, there is no need to undergo embryo screening for rare diseases if there is no family history or genetic risk.

3. Important clarifications: Genetic screening is not omnipotent.

1. It is impossible to screen all diseases: This expansion is mainly aimed at known rare single-gene diseases, while autism, congenital heart disease, polygenic diseases and diseases caused by environmental factors cannot be detected through this screening.

2. Zero risk cannot be ensured: Despite continuous advances in technology, complex situations such as embryo chimerism may still lead to incomplete accuracy of screening results, making it impossible to achieve 100% zero risk. Even if screened, pregnant women still need to conduct prenatal diagnosis in accordance with regulations during pregnancy for cases with extremely low probability of occurrence such as new mutations.

The essential difference between gene screening and modification

The core role of pre-implantation genetic testing (PGT) technology is to select healthy embryos from a large number of embryos, rather than editing genes or "customizing" babies according to specific needs. Therefore, there is no such thing as "artificially designed babies".

The number of embryos may decrease.

During the screening process, some embryos will be detected to carry disease-causing genes, and such embryos will not be able to be transplanted. For high-risk families with genetic risks, they need to make corresponding psychological preparations in advance.

The complete process of screening for rare diseases in vitro

1. Preliminary preparation: Both couples need to receive genetic counseling and conduct genetic testing to clarify the specific location of the pathogenic gene.

2. Test tube cycle operation: Start the IVF cycle, obtain eggs by inducing ovulation, and then combine the eggs with sperm to cultivate blastocysts.

3. Embryo testing: Biopsy the blastocyst and carry out expansion screening for rare diseases.

4. Embryo transfer stage: Select healthy and high-quality embryos from screened embryos for transfer.

5. Pregnancy protection measures: Pregnant women need to conduct regular prenatal check-ups during pregnancy, combined with prenatal diagnosis to provide dual protection for fetal health.

In summary

, by 2026, the expansion of the scope of screening for rare diseases will become a major breakthrough in the field of assisted reproductive eugenics, which can significantly reduce the birth rate of children with inherited rare diseases. However, in the face of increasingly advanced technology, we need to maintain a rational attitude. This technology is undoubtedly a powerful protective umbrella for high-risk families, but it is not a necessary item for ordinary families planning for pregnancy. Only by adhering to the concept of scientific screening and choosing a formal medical institution for medical treatment is the key to achieving eugenics and superior education.