• DOI:10.1067/MOB.[phone]
• Corpus ID: 31311811

Down syndrome and cell-free fetal DNA in archived maternal serum.

@article{Lee2002DownSA,
  title={Down syndrome and cell-free fetal DNA in archived maternal serum.},
  author={Thomas Lee and Erik S. Leshane and Geralyn M Messerlian and Jacob A. Canick and Antonio Farina and Walter W Heber and Diana W. Bianchi},
  journal={American journal of obstetrics and gynecology},
  year={2002},
  volume={187 5},
  pages={
          1217-21
        }
}

• Thomas Lee, E. Leshane, +4 authors D. Bianchi
• Published 1 November 2002
• Medicine
• American journal of obstetrics and gynecology

OBJECTIVE
Increased levels of cell-free fetal DNA (f-DNA) in the maternal circulation are a potential noninvasive marker for fetal Down syndrome. Our objectives were to (1) determine whether f-DNA could be quantified by using archived serum and amniotic fluid, (2) examine whether serum f-DNA levels are elevated in Down syndrome pregnancies in a case-control series matched for gestational age and duration of sample storage, and (3) determine whether f-DNA levels are elevated in the amniotic fluid of Down syndrome fetuses.

STUDY DESIGN
Eleven serum and six amniotic fluid samples previously collected and stored at -20 degrees C from gravid women carrying a 47,XY,+21 fetus were each paired with five matched control samples of identical specimen type from gravid women carrying a presumed euploid male fetus. f-DNA concentration was quantified blindly by real-time polymerase chain reaction amplification for a Y-chromosome sequence. Matched rank-sum analysis and analysis of variance were used for analysis.

RESULTS
The mean observed rank of 5.0 in the Down syndrome group was significantly higher than expected (P </=.005). Adjusted mean serum f-DNA concentrations were 41.2 genomic equivalents (GE) per milliliter for the Down syndrome cases and 24.2 GE/mL for the euploid controls (P =.002). Differences among amniotic fluid samples were not statistically significant. There was a suggestion of a sample storage effect on f-DNA concentration on the order of -0.66 GE/mL per month (P =.071).

CONCLUSION
Down syndrome pregnancies exhibit 1.7-fold higher levels of maternal serum cell-free f-DNA compared with matched controls. No such association is observed in amniotic fluid. Archived serum appears to be a useful source of clinical material for retrospective analyses but may require controlling for the duration of sample storage.