Prenatal Detection of Trisomy 2: Considerations for Genetic Counseling and Testing.
Talantova OE, Koltsova AS, Tikhonov AV, et al. Genes (Basel). 2023;14(4):913. Published 2023 Apr 14. doi:10.3390/genes14040913. Open Access: Learn more
Tags: Case Report / Case Series, 2023, Russia, RAAs
- Case report of a woman with a positive result for trisomy 2 by GW-NIPT following a negative targeted NIPT for common trisomies and subsequent abnormal ultrasounds at 13/14 and 16/17 weeks. Low-level true fetal mosaicism of trisomy 2 and multiple congenital anomalies were confirmed.
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.
Patient attitudes and preferences about expanded noninvasive prenatal testing.
Dubois ML, Winters PD, Rodrigue MA, Gekas J. Front Genet. 2023;14:976051. Published 2023 Apr 18. doi:10.3389/fgene.2023.976051 Open access: Learn more
Tags: Patient Perspectives, 2023, Canada, RAAs, CNVs
- 200 general-risk patients in Quebec were surveyed regarding their expectations for expanded NIPT.
- 88% wanted all information that could have an immediate impact on fetal health, 82% wanted all information that could have an immediate impact on infant health from birth, and almost half wanted information about RAAs and/or all genetic information that may affect the baby.
Low-level mosaic trisomy 9 at amniocentesis associated with a positive non-invasive prenatal testing for trisomy 9, maternal uniparental disomy 9, intrauterine growth restriction and a favorable fetal outcome in a pregnancy.
Chen CP, Ko TM, Chen SW, et al. Taiwan J Obstet Gynecol. 2023;62(3):457-460. doi:10.1016/j.tjog.2023.03.008. Open Access: Learn more
Tags: Case Report / Case Series, 2023, Taiwan, RAAs
- “We present low-level mosaic trisomy 9 at amniocentesis associated with a positive non-invasive prenatal testing (NIPT) for trisomy 9, maternal uniparental disomy (UPD) 9, intrauterine growth restriction (IUGR) and a favorable fetal outcome in a pregnancy.”
Late first-trimester ultrasound findings can alter management after high-risk NIPT result.
Scott F, Smet ME, Elhindi J, et al. Ultrasound Obstet Gynecol. 2023;10.1002/uog.26272. doi:10.1002/uog.26272
Tags: Clinical Experience / Clinical Utility, 2023, Australia, RAAs, CNVs
- Retrospective study of all cases with NIPT from 3 tertiary providers of obstetric ultrasound using NIPT as a first line screening test over a 4-year period.
- “The LTFU [late first trimester ultrasound] findings significantly altered the PPV of the NIPT result for trisomies 13, 18 and 21, monosomy X (MX) and rare autosomal trisomies (RATs), but not for the other sex chromosomal abnormalities or segmental imbalances (>7 Mb). An abnormal LFTU increased the PPV close to 100% for trisomies 13, 18 and 21, MX and RATs. The magnitude of the PPV alteration was highest for the lethal chromosomal abnormalities.”
- “Conclusions: LTFU after a high-risk NIPT result can alter the PPV of many chromosomal abnormalities, assisting counselling regarding invasive prenatal testing and pregnancy management.”
Application of various genetic analysis techniques for detecting two rare cases of 9p duplication mosaicism during prenatal diagnosis.
Zhang S, Zhou Y, Xiao G, Qiu X. Mol Genet Genomic Med. 2023;e2229. doi:10.1002/mgg3.2229 Open access: Learn more
Tags: Case Report / Case Series, 2023, China, RAAs, CNVs
- “Herein, we describe the clinical phenotypes and various prenatal diagnostic processes used for two rare cases of 9p duplication mosaicism [initially suspected based on NIPT results] and review the prior literature in the field to evaluate the merits of different methods for diagnosing mosaic 9p duplication.”
- “This study demonstrated the potential of using NIPT to suggest 9p duplication in early pregnancy.”
Evaluation of the clinical effects of non-invasive prenatal screening for diseases associated with aneuploidy and copy number variation.
Zhu S, Jia C, Hao S, et al. Mol Genet Genomic Med. 2023;e2200. doi:10.1002/mgg3.2200 Open Access: Learn more
Tags: Clinical Experience / Clinical Utility, 2023, China, RAAs, CNVs
- Prospective study of over 25,000 pregnant women who had NIPS-PLUS. 415 individuals had positive results, including 275 indicating aneuploidy and 140 indicating microdeletion/microduplication syndromes (MMS).
- Following amniocentesis, 188 were confirmed as true positives (including 41 cases of RATs and 57 MMS).
- PPV was 25.63% for RATs, PPV was 44.66% for CNVs <5 Mb, PPV was 29.73% for CNVs >5 Mb.
Prenatal Screening for Microdeletions and Rare Autosomal Aneuploidies
Fiorentino D, Dar P.. Clin Obstet Gynecol. 2023;66(3):579-594. doi:10.1097/GRF.0000000000000799
Tags: Review / Meta-Analysis, 2023, International, RAAs, CNVs
- “Conclusion: To conclude, cfDNA is an attractive screening tool for chromosomal abnormalities that otherwise do not have dedicated screening modalities. However, the expansion of routine prenatal genetic screening to include rare syndromes has to balance patients’ desire for information about their pregnancy and the clinical utility of a screening test. Unfortunately, for many CNVs and RAAs, the clinical utility of this screening remains unclear. The principle of patient autonomy would dictate that these commercially available tests not be withheld from patients who desire greater information regarding their pregnancy, but detailed counseling is needed to ensure that the benefits and limitations of expanded cfDNA are clearly understood.”
A Case of Maternal Uniparental Disomy of Chromosome 6 with Intrauterine Growth Restriction.
Feng L, Ma Y, Xu Y. Altern Ther Health Med. 2023;29(7):447-449. Open Access: Learn more
Tags: Case Report / Case Series, 2023, China, RAAs
- NIPT result of trisomy 6. FISH (fluorescence in situ hybridization) and whole exome sequencing on amniocytes revealed no abnormalities. CMA on amniocytes detected UPD 6. Ultrasound at 28 weeks gestation showed intrauterine growth restriction.
Low-level mosaic trisomy 2 at amniocentesis in a pregnancy associated with positive NIPT and CVS results for trisomy 2, maternal uniparental disomy 2, perinatal progressive decrease of the aneuploid cell line, cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, intrauterine growth restriction and a favorable fetal outcome.
Chen CP, Wu FT, Chern SR, et al. Taiwan J Obstet Gynecol. 2023;62(4):571-576. doi:10.1016/j.tjog.2023.05.002. Open Access: Learn more
Tags: Case Report / Case Series, 2023, Taiwan, RAAs
- “Mosaic trisomy 2 at prenatal diagnosis should alert the possibility of UPD 2 and include a UPD 2 testing. Low-level mosaic trisomy 2 at amniocentesis can be associated with perinatal progressive decrease of the aneuploid cell line and a favorable fetal outcome.”