A Case Report of a Feto-Placental Mosaicism Involving a Segmental Aneuploidy: A Challenge for Genome Wide Screening by Non-Invasive Prenatal Testing of Cell-Free DNA in Maternal Plasma.20231130160922

A Case Report of a Feto-Placental Mosaicism Involving a Segmental Aneuploidy: A Challenge for Genome Wide Screening by Non-Invasive Prenatal Testing of Cell-Free DNA in Maternal Plasma.

De Falco L, Vitiello G, Savarese G, et al. Genes (Basel). 2023;14(3):668. Published 2023 Mar 7. doi:10.3390/genes14030668. Open Access: Learn more

Tags: Case Report / Case Series, 2023, Italy, CNVs

  • Case report of 44.1 Mb 4p dup detected by NIPT at 12 weeks. Amniocentesis was performed at 18 weeks; SNP (single nucleotide polymorphism) array found a de novo2 Mb deletion on chromosome 4 near the Wolf-Hirschhorn syndrome critical region and a normal 46,XY karyotype was identified by G-banding analysis.
  • Studies of fetal and placental tissue confirmed presence of type VI true fetal mosaicism, with SNP array on 3 placental samples showing different results.
Clinical Experience with Genome-Wide Noninvasive Prenatal Screening in a Large Cohort of Twin Pregnancies.20231130160555

Clinical Experience with Genome-Wide Noninvasive Prenatal Screening in a Large Cohort of Twin Pregnancies.

De Falco L, Savarese G, Savarese P, et al. Genes (Basel). 2023;14(5):982. Published 2023 Apr 26. doi:10.3390/genes14050982. Open Access: Learn more

Tags: Laboratory Performance / Laboratory Experience, 2023, Italy, RAAs, CNVs

  • Cohort of 1,244 twin pregnancy samples undergoing NIPT, of which 61.5% chose GW-NIPT for RAAs and CNVs in addition to common trisomies.
  • There were 29 high-risk results: 18 T21, one T18, 6 RAA, and 4 CNV cases. Clinical and diagnostic follow-up was available for 27/29 (93%) of these cases.
  • Clinical follow-up was available for 96.6% of low-risk cases; all were true negatives.
Positive predictive values and outcomes for uninformative cell-free DNA tests: An Italian multicentric Cytogenetic and cytogenomic Audit of diagnOstic testing (ICARO study).20221130161742

Positive predictive values and outcomes for uninformative cell-free DNA tests: An Italian multicentric Cytogenetic and cytogenomic Audit of diagnOstic testing (ICARO study).

Grati FR, Bestetti I, De Siero D, et al.. Prenat Diagn. 2022;42(13):1575-1586. doi:10.1002/pd.6271.

Tags: Laboratory Performance / Laboratory Experience, 2022, Italy, RAAs

  • “Diagnostic test results were collected for 1327 women with a positive NIPT. The highest PPVs were for Trisomy (T) 21 (624/671, 93%) and XYY (26/27, 96.3%), while rare autosomal trisomies (9/47, 19.1%) and recurrent microdeletions (8/55, 14.5%) had the lowest PPVs.”
  • Prenatal diagnostic test results were collected by Italian laboratories between 2013 and March 2020 for 1327 women.
  • PPV for RATs was 19.1% (9/47). PPV for segmental imbalances >7 Mb was 24.1% (7/29).
The clinical utility of genome-wide non invasive prenatal screening20171130181310

The clinical utility of genome-wide non invasive prenatal screening

Fiorentino F, Bono S, Pizzuti F, et al. Prenat Diagn. 2017;37(6):593-601. doi:10.1002/pd.5053.

Tags: Clinical Experience / Clinical Utility, 2017, Italy, RAAs, CNVs

  • This publication examined the test performance of NIPT for the common aneuploidies compared to that of Expanded NIPT. Expanded NIPT detected 7.4% potentially viable clinically relevant chromosome abnormalities that would have not been detected if NIPT was limited to the common aneuploidies, which resulted in a statistically significant higher sensitivity than did non-Expanded NIPT without a statistically significant impact on specificity.