Cell Free Fetal DNA Flashcards
1
Q
What % of DNA in maternal blood is fetal?
A
Approx 2-6% (some studies suggest 10-20%).
2
Q
Origin of cffDNA?
A
Apoptosis trophoblasts making up placenta- placental microparticles are shred into maternal blood stream.
3
Q
What gestation can you detect cffDNA?
A
As early as 5 weeks, increases as pregnancy progresses!
4
Q
What size are cffDNA fragments?
A
200bp (smaller than free maternal DNA).
