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Rapid detection of trisomy 21 by gene dosage analysis using quantitative real‐time polymerase chain reaction
Author(s) -
Tsujie Tomoko,
Takemura Masahiko,
Kimura Tadashi,
Shimoya Koichiro,
Tsutsui Tateki,
Ogita Kazuhide,
Ozaki Mamoru,
Murata Yuji
Publication year - 2006
Publication title -
journal of obstetrics and gynaecology research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 50
eISSN - 1447-0756
pISSN - 1341-8076
DOI - 10.1111/j.1447-0756.2006.00428.x
Subject(s) - trisomy , microbiology and biotechnology , taqman , polymerase chain reaction , aneuploidy , karyotype , real time polymerase chain reaction , chromosome , fluorescence in situ hybridization , gene , biology , medicine , genetics
Aim: Rapid detection of fetal aneuploidy helps inform a mother’s choice about the course of her pregnancy. Obtaining results by fluorescent in situ hybridization (FISH) requires more than 24 h, and thus a more rapid method is needed. Methods: Conventional G‐banding and FISH for chromosome 21 were performed for cultured amniocytes. Genomic DNA was extracted from uncultured amniocytes obtained from 23 patients. TaqMan polymerase chain reaction (PCR) primers were designed to amplify the potassium voltage gated channel gene on chromosome 21q22.12 and the ribosomal phosphoprotein gene on 18q21.1. Quantitative real‐time PCR was performed for these two gene fragments and the differences of the threshold cycle (Ct) of the two genes (Ct 18–Ct 21) were calculated for each sample. Results: G‐banding revealed that 19 patients had a normal karyotype and four had trisomy 21. FISH resulted in one case of a false positive. The ΔCt values (Ct 18–Ct 21) of trisomy 21 patients were significantly higher than the values of individuals with normal karyotypes ( P < 0.001) and there was no overlapping. Conclusions: Fetal trisomy 21 is rapidly detectable by gene dosage analysis from amniocytes using quantitative real‐time PCR.