Title

Biological explanations for discordant noninvasive prenatal test results: Preliminary data and lessons learned.

Document Type

Article

Publication Date

5-1-2018

JAX Location

Reprint Collection

JAX Source

Prenat Diagn 2018 May; 38(6):445-458

PMID

29633279

DOI

https://doi.org/10.1002/pd.5260

Abstract

OBJECTIVE: Maternal plasma cell-free DNA (cfDNA) analysis is a powerful screening tool for Down syndrome. In a pilot series, we examined biologic causes of discordance between the cfDNA test results and the fetal karyotype. We also explored the feasibility of obtaining trio biospecimens by using parental engagement.

METHODS: A convenience sample of women with discordant cfDNA results were recruited by their care providers. We provided shipping materials and instructions for biospecimen collection. Maternal, newborn, and placental samples were examined with droplet digital PCR.

RESULTS: Thirteen of 15 women successfully had biospecimens obtained remotely. High-quality DNA was extracted in 12 of 13 women. Presumed biologic etiologies for discordance were identified in 7 of 12 women: 3 cases from additional clinical review (male renal transplant, vanishing twin, and colon cancer) and 4 cases from additional laboratory investigation using droplet digital PCR (3 with confined placental mosaicism and 1 with true fetal mosaicism).

CONCLUSIONS: Understanding the biology behind cfDNA-fetal karyotype discordancy is useful for follow-up clinical care. Our study suggests that most cases could be resolved by using a trio biospecimen protocol and parental involvement. To improve accuracy, additional sequencing of biospecimens will be required.

Comments

The studies here were funded by in-kind support from each of the institutions represented except for the NIH.

Please contact the Joan Staats Library for information regarding this document.

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