2023 ACMG Annual Clinical Genetics Meeting Digital Edition: Poster Gallery-Impact of NIPS Outside of Scope Reporting on Fetal and Maternal Cytogenetic Testing

Pdf Summary

This document discusses the impact of non-invasive prenatal screening (NIPS) on fetal and maternal cytogenetic testing. NIPS is a screening method that analyzes cell-free DNA derived from the mother and placenta to detect prenatal chromosome abnormalities. The document highlights the need for confirmatory testing when NIPS results are inconclusive or outside the scope of testing.<br /><br />The results of confirmatory cytogenetic testing were reviewed for 294 cases over a three-year period. Approximately one-third of cases with results outside the scope of NIPS had pathogenic or variant of uncertain significance (VUS) findings. Many of these findings involved abnormalities in the X and Y chromosomes. These findings varied between VUS, incidental, benign, and copy number variants (CNVs) below the size threshold for prenatal reporting.<br /><br />There was no consistency in which patients underwent confirmatory testing (mother, fetus, or both) or which test was ordered (karyotype, chromosomal microarray, or both). This suggests that there should be further study on the utility and criteria for reporting findings outside the scope of NIPS.<br /><br />The results were categorized as normal, abnormal/VUS, related, or unrelated to the NIPS result. The most common abnormal/VUS findings were related to rearrangements and sex chromosome abnormalities. There were also CNVs identified, some of which were reportable and others were non-reportable according to laboratory guidelines.<br /><br />Overall, this study highlights the need for confirmatory testing when NIPS results are inconclusive or outside the scope of testing. It also emphasizes the variability in testing approaches and the potential impact on prenatal chromosome abnormality detection. Further research is needed to establish consistent reporting criteria for findings outside the scope of NIPS.

Asset Subtitle

Presenting Author - Hannah Anderson, MS; Co-Author - Erica F. Andersen, PhD, FACMG; Co-Author - Katie Rudd, PhD, FACMG; Co-Author - Ting Wen, PHD, MBBS; Co-Author - Michelle Q. Bosworth, MS;

Meta Tag

Cell free DNA/cfDNA

Genetic Testing

Noninvasive prenatal screening (NIPS)

Prenatal Diagnosis

Co-Author Erica F. Andersen, PhD, FACMG

Co-Author Katie Rudd, PhD, FACMG

Co-Author Ting Wen, PHD, MBBS

Co-Author Michelle Q. Bosworth, MS

Presenting Author Hannah Anderson, MS

Keywords

non-invasive prenatal screening

NIPS

fetal cytogenetic testing

maternal cytogenetic testing

cell-free DNA

prenatal chromosome abnormalities

confirmatory testing

variant of uncertain significance

X and Y chromosomes

copy number variants