<abstract xmlns="http://www.w3.org/1999/xhtml"> Background: Trisomy 21 or Down syndrome (DS) is the most common aneuploidy disorder. Fetal karyotypic analysis remains the criterion standard for prenatal diagnosis of DS, although the method is time consuming and requires skilled personnel. Real-time quantitative polymerase chain reaction (qPCR) can be used to determine a difference in the amount of gene copy by calculation of the difference between the cycle threshold (ΔCT) of a tested gene and a reference gene.Objectives: To develop a rapid qPCR diagnostic method for trisomy 21.Methods: Ten DS patients with the known karyotype of trisomy 21 were enrolled. Their parents were included as controls. D21S11 locus on chromosome 21 and SM locus on chromosome 16 from each subject were amplified by qPCR. The D21S11/SM ΔCT and 2-ΔΔCT values were compared between DS patients and their parents.Results: The D21S11/SM ΔCT values of the DS patients were higher than their respective controls except for one family. The mean 2-ΔΔCT value between patients and mothers was 1.88 ± 0.95 (95% CI 1.20-2.56), and between fathers and mothers as controls was 1.06 ± 0.68 (95% CI 0.58-1.54).Conclusion: The diagnostic method of trisomy 21 by using qPCR is feasible, although false negative results may occur. Using more index genes is recommended to increase the sensitivity and specificity.</abstract>

Background: Trisomy 21 or Down syndrome (DS) is the most common aneuploidy disorder. Fetal karyotypic analysis remains the criterion standard for prenatal diagnosis of DS, although the method is time consuming and requires skilled personnel. Real-time quantitative polymerase chain reaction (qPCR) can be used to determine a difference in the amount of gene copy by calculation of the difference between the cycle threshold (ΔCT) of a tested gene and a reference gene.Objectives: To develop a rapid qPCR diagnostic method for trisomy 21.Methods: Ten DS patients with the known karyotype of trisomy 21 were enrolled. Their parents were included as controls. D21S11 locus on chromosome 21 and SM locus on chromosome 16 from each subject were amplified by qPCR. The D21S11/SM ΔCT and 2-ΔΔCT values were compared between DS patients and their parents.Results: The D21S11/SM ΔCT values of the DS patients were higher than their respective controls except for one family. The mean 2-ΔΔCT value between patients and mothers was 1.88 ± 0.95 (95% CI 1.20-2.56), and between fathers and mothers as controls was 1.06 ± 0.68 (95% CI 0.58-1.54).Conclusion: The diagnostic method of trisomy 21 by using qPCR is feasible, although false negative results may occur. Using more index genes is recommended to increase the sensitivity and specificity.

Brief communication (Original). Rapid diagnosis of trisomy 21 by relative gene copy using real-time quantitative polymerase chain reaction

Department of Pediatrics, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200,

Division of Genetics and Metabolism, Children’s National Medical Center, Washington DC,

Asian Biomedicine

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Background: Trisomy 21 or Down syndrome (DS) is the most common aneuploidy disorder. Fetal karyotypic analysis remains the criterion standard for prenatal...

Brief communication (Original). Rapid diagnosis of trisomy 21 by relative gene copy using real-time quantitative polymerase chain reaction

Published Online: Feb 04, 2017

Page range: 399 - 403

DOI: https://doi.org/10.5372/1905-7415.0803.306

Keywords
Down syndrome, gene copy difference, prenatal diagnosis, real-time quantitative polymerase chain reaction, trisomy 21

© 2017

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Brief communication (Original). Rapid diagnosis of trisomy 21 by relative gene copy using real-time quantitative polymerase chain reaction

Published Online: Feb 04, 2017

Page range: 399 - 403

DOI: https://doi.org/10.5372/1905-7415.0803.306

KeywordsDown syndrome, gene copy difference, prenatal diagnosis, real-time quantitative polymerase chain reaction, trisomy 21

© 2017

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
Down syndrome, gene copy difference, prenatal diagnosis, real-time quantitative polymerase chain reaction, trisomy 21