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Genetic Counseling in Assisted Reproductive Technology
Published in Carlos Simón, Carmen Rubio, Handbook of Genetic Diagnostic Technologies in Reproductive Medicine, 2022
Trisomy 13, also known as Patau syndrome, is associated with several life-threatening medical problems. More than 95% of pregnancies identified to have trisomy 13 miscarry. Trisomy 13 is observed in only about 1/20,000 births and affected babies usually cannot live for more than a few weeks or months. Babies with trisomy 13 typically have multiple congenital anomalies, including heart defects and brain or spinal cord abnormalities.
Prenatal Diagnosis and Screening for Aneuploidy
Published in Vincenzo Berghella, Obstetric Evidence Based Guidelines, 2022
Sarah Harris, Angie Jelin, Neeta Vora
CVS or amniocentesis achieves the diagnosis by a study of the fetal chromosomes, which reveals trisomy 13. In the neonate, usually peripheral blood is cultured and karyotyped.
Second-trimester screening for fetal abnormalities
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Jolene C. Muscat, Anthony M. Vintzileos
In counseling patients, it is important to emphasize that multiple maternal serum screening protocols were developed primarily to detect trisomy 21, and the patterns of serum markers observed in pregnancies affected by trisomy 18 and other fetal chromosomal abnormalities are different. In trisomy 18, MSAFP and unconjugated estriol are low; however, in contrast to Down syndrome, hCG value is low as well. Although these results are well correlated with trisomy 18, a positive second-trimester serum screen has poor sensitivity and poor prediction for trisomy 18 (12). By contrast, genetic ultrasound to evaluate for characteristic sonographic findings associated with this diagnosis is highly sensitive in identifying fetuses with the disorder (13,14). Ultrasound evaluation of fetuses with trisomy 18 will be discussed later in this chapter. Trisomy 13 is usually associated with normal levels of all three maternal serum markers, except in cases where open fetal defects are present. In fetal triploidy, all three biochemical markers are low. Table 4 summarizes the changes in serum marker levels in various fetal chromosomal abnormalities.
Clinical application of noninvasive prenatal testing in twin pregnancies: a single-center experience
Published in Expert Review of Molecular Diagnostics, 2023
Yanmei Luo, Bin Hu, Yang Long, Yan Pan, Lupin Jiang, Wei Xiong, Huanhuan Xu, Liang Xu, Dan Wang
In this study, trisomy 21 syndrome was detected by NIPT in twin pregnancies with a sensitivity of 100.00%, a specificity of 99.79%, and a PPV) of 57.14%. For trisomy 18, these values were 100.00%, 99.94%, and 50%, respectively. For trisomy 13, these values were all 100.00%. Compared with our previous study in 2020 in single pregnancies, trisomy 21 syndrome was detected by NIPT with a sensitivity of 100.00%, a specificity of 99.95%, and a PPV of 84.00%. For trisomy 18, these values were 100.00%, 99.97%, and 48.15%, respectively. For trisomy 13, these values were 100.00%, 99.94%, and 14.29%, respectively [26]. In this single-centered retrospective study, we show that NIPT has high sensitivity and specificity in detecting common fetal trisomy in singleton and twin pregnancies, consistent with the study by Gil et al [36]. Because NIPT behaves similarly in twin and singleton pregnancies, some researchers believe that NIPT could serve as a first-line screening for twin pregnancies [37–39]. This suggests that positive NIPT results can be used reliably used as an indication for further prenatal diagnosis of twin pregnancy. However, the PPV of NIPT was highest for T13 (100%), moderate for T21 (57.14%), and relatively low for T18 (50%) in twin pregnancies. We found that the PPV of NIPT in twin pregnancies was not the same as that in singleton pregnancies. Due to the small number of cases in this study, especially T18 and T13, further data are needed to assess the NIPT detection rate in twin pregnancies accurately [23].
Keratoconus in a child with partial trisomy 13
Published in Ophthalmic Genetics, 2021
Julia Ernst, Amgad Eldib, Hannah L. Scanga, Ken K. Nischal
Patau syndrome (complete trisomy 13) is a rare abnormality that manifests as a triad of microphthalmia, cleft lip and palate, and polydactyly. Most patients present at birth with severe malformations leading to early death. However, in incomplete trisomy 13, patients may show a few dysmorphic features and relatively normal development (1). Patients usually require multiple medical treatments by different specialists. The frequently described ocular manifestations are microphthalmia, uveal tract colobomas, retinal dysplasia, persistence and hyperplasia of the primary vitreous body, cataract and lens luxation (2). To our knowledge, keratoconus has not been reported in a patient with complete, mosaic or partial trisomy 13. Keratoconus is characterized by progressive thinning and cone-shaped protrusion of the cornea, leading to progressive visual impairment (3). It is mostly a sporadic disorder with major risk factors including eye rubbing, atopy, systemic disorders and contact lens use. Clinical studies suggest genetic components in its etiology, but the contributing alleles remain elusive (3).
Is the presence of corpus callosum predictable in the first trimester?
Published in Journal of Obstetrics and Gynaecology, 2018
Hakan Kalaycı, Ebru Tarım, Halis Özdemir, Tayfun Çok, Ayşe Parlakgümüş
This is the first study to include PCA screening as well as MB and F measurements. Pati et al. (2012) visualised PCAs at gestational weeks 12–20 in 71 patients. They measured the length of the PCAs and found a correlation with gestational week. In addition, the presence of the CC was confirmed by ultrasonography after gestational week 22. Díaz-Guerrero et al. (2013) searched 150 patient records for PCAs and detected the PCA path in 97.2% of their patients (144/150), which agreed with our study results (98%). Two of 150 patients had abnormal PCA paths with confirmation of ACC in the second trimester. Two other foetuses had triploidy, and a third had trisomy 13. In contrast, in our study, two patients with normal PCA paths had trisomy 13, and the other had trisomy 21.