Lei Sun1, Zuqian Fan2, Xunjin Weng2, Xuehe Ye2, Ju Long2, Kepeng Fu2, Shanhuo Yan2, Bo Wang3, Yongguang Zhuo2, Xinxing Liu2, Kegan Lao2. 1. Laboratory of Medical Genetics, Qinzhou Maternal and Child Health Hospital, Guangxi, China. Electronic address: sunshijie12345@163.com. 2. Laboratory of Medical Genetics, Qinzhou Maternal and Child Health Hospital, Guangxi, China. 3. Genetics Laboratory, Hubei Maternal and Child Health Hospital, Hubei, China.
Abstract
OBJECTIVE: Development of a qPCR test for the detection of trisomy 21 using segmental duplications. METHODS: Segmental duplications in the TTC3 gene on chromosome 21 and the KDM2A gene on chromosome 11 were selected as molecular markers for the diagnostic qPCR assay. A set of consensus primers selected from the conserved regions of these segmental duplications were used to amplify internal diverse sequences that were detected and quantified with different probes labeled with distinct fluorescence. The copy numbers of these two fragments were determined based on the ΔCq values of qPCR. The results of qPCR for prenatal and neonatal screening of Down's syndrome were compared with the conventional karyotype analysis by testing 82 normal individuals and 50 subjects with Down's syndrome. RESULTS: The ΔCq values of segmental duplications on chr21 and 11 ranged between 0.33 and 0.75 in normal individuals, and between 0.91 and 1.18 in subjects with Down's syndrome. The ΔCq values of these two segmental duplications clearly discriminated Down's syndrome from normal individuals (P<0.001). Furthermore, the qPCR results were consistent with karyotype analysis. CONCLUSION: Our qPCR can be used for rapid prenatal and neonatal screening of Down's syndrome.
OBJECTIVE: Development of a qPCR test for the detection of trisomy 21 using segmental duplications. METHODS: Segmental duplications in the TTC3 gene on chromosome 21 and the KDM2A gene on chromosome 11 were selected as molecular markers for the diagnostic qPCR assay. A set of consensus primers selected from the conserved regions of these segmental duplications were used to amplify internal diverse sequences that were detected and quantified with different probes labeled with distinct fluorescence. The copy numbers of these two fragments were determined based on the ΔCq values of qPCR. The results of qPCR for prenatal and neonatal screening of Down's syndrome were compared with the conventional karyotype analysis by testing 82 normal individuals and 50 subjects with Down's syndrome. RESULTS: The ΔCq values of segmental duplications on chr21 and 11 ranged between 0.33 and 0.75 in normal individuals, and between 0.91 and 1.18 in subjects with Down's syndrome. The ΔCq values of these two segmental duplications clearly discriminated Down's syndrome from normal individuals (P<0.001). Furthermore, the qPCR results were consistent with karyotype analysis. CONCLUSION: Our qPCR can be used for rapid prenatal and neonatal screening of Down's syndrome.
Authors: Antonio R Porras; Matthew S Bramble; Kizito Mosema Be Amoti; D'Andre Spencer; Cécile Dakande; Hans Manya; Neerja Vashist; Esther Likuba; Joachim Mukau Ebwel; Céleste Musasa; Helen Malherbe; Bilal Mohammed; Carlos Tor-Diez; Dieudonné Mumba Ngoyi; Désiré Tshala Katumbay; Marius George Linguraru; Eric Vilain Journal: Eur J Med Genet Date: 2021-06-20 Impact factor: 2.465
Authors: Elizabeth Schaeffer; Bruno López-Bayghen; Adina Neumann; Leonardo M Porchia; Rafael Camacho; Efraín Garrido; Rocío Gómez; Felipe Camargo; Esther López-Bayghen Journal: Biomed Res Int Date: 2017-06-22 Impact factor: 3.411