Prenatal Diagnosis of Uniparental Disomy in Cases of Rare Autosomal Trisomies Detected Using Noninvasive Prenatal Test: A Case of Prader-Willi Syndrome.
Hong DK, Park JE, Kang KM, et al. Diagnostics (Basel). 2023;13(4):580. Published 2023 Feb 4. doi:10.3390/diagnostics13040580. Open Access: Learn more
Tags: Case Report / Case Series, 2023, South Korea, RAAs
- “Overall, six cases were diagnosed with RATs. There was a suspicion of trisomies of chromosomes 7, 8, and 15 in two cases each. However, these cases were confirmed to have a normal karyotype using amniocentesis. In one of six cases, PWS [Prader-Willi syndrome] caused by maternal UPD 15 was diagnosed using MS-PCR and MS-MLPA. We propose that in cases where RAT is detected by NIPT, UPD should be considered following trisomy rescue. Even if amniocentesis confirms a normal karyotype, UPD testing (such as MS-PCR and MS-MLPA) should be recommended for accurate assessment, as an accurate diagnosis can lead to appropriate genetic counseling and improved overall pregnancy management.”
Case report: Detection of fetal trisomy 9 mosaicism by multiple genetic testing methods: Report of two cases.
Ma N, Zhu Z, Hu J, et al. Front Genet. 2023;14:1121121. Published 2023 Mar 10. doi:10.3389/fgene.2023.1121121. Open Access: Learn more
Tags: Case Report / Case Series, 2023, China, RAAs
- “The non-invasive prenatal testing (NIPT) results suggested trisomy 9 in two fetuses. Karyotype analysis of amniocytes showed a high level (42%-50%) of mosaicism, and chromosomal microarray analysis (CMA) of uncultured amniocytes showed no copy number variation (CNV) except for large fragment loss of heterozygosity. Ultrasound findings were unmarkable except for small for gestational age… The results [of molecular testing of fetal and placental tissue samples] confirmed the presence of true fetoplacental mosaicism with levels of trisomy 9 mosaicism from 76% to normal in various tissues.”
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.
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.
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.”
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.”
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.”
Mosaic trisomy 16 at amniocentesis in a pregnancy associated with positive non-invasive prenatal testing for trisomy 16, placental trisomy 16, intrauterine growth restriction, intrauterine fetal death, cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, and prenatal progressive decrease of the aneuploid cell line.
CP, Wu FT, Chen YY, et al. Taiwan J Obstet Gynecol. 2023;62(4):597-601. doi:10.1016/j.tjog.2023.05.008. Open Access: Learn more
Tags: Case Report / Case Series, 2023, Taiwan, RAAs
“Mosaic trisomy 16 at amniocentesis can be associated with positive NIPT for trisomy 16, placental trisomy 16, IUGR [intrauterine growth restriction], IUFD [intrauterine fetal demise], cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, and prenatal progressive decrease of the aneuploid cell line.”
Prenatal diagnosis of a case with complete and uniform tetrasomy 12p by the utility of noninvasive prenatal testing.
Zhang F, Yin T, Tang X, et al. J Assist Reprod Genet. 2023;40(9):2233-2240. doi:10.1007/s10815-023-02896-8.
Tags: Case Report / Case Series, 2023, China, CNVs
- “NIPT results showed increased signal from chromosome 12p. Subsequent prenatal diagnostic testing by karyotype revealed 47,XY,+i(12p), and CMA displayed four copies of 12p: 12p13.33-12p11.1(173786_34835641)×4. The CNV-seq results of the fetal skin and the fetal side of placenta showed four copies of 12p13.33-p11 and an estimated chimeric duplication of 34.08 Mb (chimerism ratio: 10%) in 12p13.33-p11, respectively. However, no abnormality was detected by CNV-seq at the maternal side of placenta. Our findings suggest that a positive signal from chromosome 12p on NIPT should raise suspicion for PKS [Pallister-Killian syndrome]. With the wide application of NIPT, the true positive of incidental finding is expected to increase.”