cfDNA
Pronunciation: see-ef-dee-en-ay
Also written as: cfDNA — cell-free DNA
Cell-free DNA, fragments of fetal DNA circulating in maternal blood used for non-invasive prenatal screening.
Full Definition
Cell-free DNA (cfDNA) refers to small fragments of DNA circulating freely in maternal plasma, a portion of which originates from the placenta and reflects the fetal genetic composition. This forms the basis of non-invasive prenatal testing (NIPT), which analyzes the ratio of different chromosomes to screen for common aneuploidies such as trisomies 21, 18, and 13. The fetal fraction typically comprises 3-13% of total cfDNA in maternal circulation and increases with gestational age. cfDNA testing offers higher sensitivity and specificity than traditional serum screening methods. However, results may be affected by maternal factors, placental mosaicism, or technical limitations, requiring confirmation through invasive diagnostic procedures when abnormalities are detected.
Usage
Usage note: Note lowercase when written out; hyphenate cell-free.
In Context
- "cfDNA analysis revealed low risk for trisomy 21 with a fetal fraction of 8.2%." — NIPT report
- "The cfDNA test was repeated due to insufficient fetal fraction in the initial sample." — Laboratory communication