Down syndrome and cell-free fetal DNA in archived maternal serum.
Author(s): Lee T, LeShane ES, Messerlian GM, Canick JA, Farina A, Heber WW, Bianchi DW
Publication: Am J Obstet Gynecol, 2002, Vol. 187, Page 1217-21
PubMed ID: 12439507 PubMed Review Paper? No
Purpose of Paper
The purpose of this paper was to determine the effects of fetal down syndrome and frozen storage duration on fetal DNA levels in serum and amniotic fluid from pregnant women.
Conclusion of Paper
Fetal DNA concentrations increased with gestational age and were higher in serum, but not amniotic fluid, from women carrying fetuses with down syndrome than specimens from women carrying euploid fetuses. There was a non-significant trend toward decreased fetal DNA with increased storage of serum, but the same was not true for storage of amniotic fluid.
Studies
-
Study Purpose
The purpose of this study was to determine the effects of fetal down syndrome and frozen storage duration on fetal DNA levels in serum and amniotic fluid from pregnant women. 11 frozen serum and 6 frozen amniotic fluid specimens from women carrying male fetuses with down syndrome (47, XY, +21 ) were compared with 55 frozen serum and 30 amniotic fluid specimens from women carrying normal (euploid) male fetuses at the same gestational ages and matched for storage duration at -20°C. Specimens were thawed at 37°C, and fetal DNA was quantified by real-time PCR amplification of the DYS1 locus. Storage effects were investigated using only the 55 serum and 30 amniotic fluid specimens from women carrying euploid fetuses.
Summary of Findings:
Fetal DNA concentrations increased with gestational age. Rank sum analysis showed a higher than expected serum fetal DNA level when the patient was carrying a fetus with down syndrome (p<0.005) versus a normal fetus. Further, serum from women carrying fetuses with down syndrome had 1.7 fold more fetal DNA than serum from women carrying euploid fetuses (p=0.002). Fetal DNA levels in amniotic fluid were comparable in women carrying down syndrome and euploid fetuses. A non-significant decrease of 0.66 genome equivalents (GE) fetal DNA/month of serum storage was observed, but no similar trend was observed after storage of amniotic fluid.
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Down Syndrome
- Pregnant
Platform:
Analyte Technology Platform DNA Real-time qPCR Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Preaquisition Patient genotype 47, XY, +21
46, XY
Preaquisition Diagnosis/ patient condition Pregnant with Down syndrome fetus
Pregnant with euploid fetus
Storage Storage duration 16-36 months
Preaquisition Patient age 15-19 weeks gestation