Language
Country/Area
No result found
The mysterious journey of fetal DNA: How does it flow freely in maternal blood?
With the rapid development of medical science and technology, fetal DNA detection technology is changing the face of prenatal diagnosis for pregnant women. Cell-free fetal DNA (cffDNA) refers to fetal DNA fragments that circulate freely in the mother's blood. This great discovery not only enhances the ability to monitor fetal health, but also opens up new directions for future obstetric medicine.
The emergence of cffDNA makes fetal pathology detection non-invasive, and pregnant women no longer have to bear the risks brought by traditional examinations.
Source and characteristics of cffDNA
cffDNA mainly comes from the mother's placental trophoblast cells. When these cells release tiny particles into the mother's blood, the fetal DNA fragments (about 200 base pairs long) begin to travel freely in the mother's blood. It is worth mentioning that the fetal DNA in cfDNA accounts for 11% to 13.4% of the free DNA in maternal blood. The amount of cffDNA increases as pregnancy progresses but is no longer detectable within two hours after delivery.
cffDNA analysis can provide diagnosis of fetal conditions earlier than traditional methods, which provides a safe option for pregnant women.
Laboratory test methods
Currently, a variety of laboratory methods have been developed to screen cffDNA, mainly including:
- Massively Parallel Shotgun Sequencing (MPSS)
- Targeted Massive Parallel Sequencing (t-MPS)
- Single Nucleotide Polymorphism (SNP) method
Maternal blood samples were collected through venous blood sampling at about ten weeks of pregnancy, and plasma was separated from maternal blood using centrifugation technology before cffDNA was extracted.
cffDNA detection technology
In actual cffDNA analysis, multiple technologies are used, including real-time PCR, digital PCR, and high-throughput sequencing. Real-time PCR uses fluorescent probes to monitor DNA amplification and has higher sensitivity and specificity. Digital PCR can quantify cffDNA fragments more accurately and is suitable for multiplex detection.
These advanced detection technologies make it possible to identify the sex of the fetus, detect single gene diseases and chromosomal abnormalities.
Application Scope
cffDNA analysis has a wide range of applications, including:
1. Identification of fetal sex
By analyzing cffDNA in maternal plasma, we can determine the sex of the fetus, which is particularly important when detecting sex-related genetic diseases.
2. Congenital adrenal hyperplasiaThis disease affects the gender characteristics of female fetuses. Testing the Y chromosome sequence of cffDNA can help determine the gender of the fetus and intervene early.
3. Bloodline Identification
Non-invasive paternity testing can be performed on the fetus as early as nine weeks of pregnancy.
4. Detection of single gene diseases
For certain specific genetic diseases, cffDNA can also be used for effective detection, which provides an opportunity for early intervention.
5. Deformities and chromosomal abnormalities
cffDNA can help detect common fetal chromosomal abnormalities, such as Down syndrome.
Future Outlook
With the advancement of technology, cffDNA detection technology will become more mature. More functions will be possible, including screening for more specific gene variants, which will undoubtedly play an important role in improving the accuracy and sensitivity of prenatal diagnosis.
However, the widespread use of FCCDNA also brings potential ethical issues. How should we properly deal with these issues in the future?
