The establishment and application of double TaqMan real-time fluorescence nested PCR method for rapid detection of α-thalassemia SEA deletion / 中华检验医学杂志

ABSTRACT

Objective To establish a double TaqMan real-time fluorescence nested PCR method for rapid detection of α-thalassemia SEA deletion.Methods One hundred blood samples for thalassemia screening were collected from May to July of 2010 in the Tianhe Maternal and Child Health Hospital of Guangzhou.Seven fetal specimens for prenatal diagnosis were collected from December 2010 to February 2011 in Dongguan TungWah Hospital(2 villi and 5 amniotic fluid specimens).Fifty samples of α-thalassemia SEA deletion with genotyping results were selected from the sample bank of our laboratory.The double TaqMan real-time fluorescence nested PCR was applied to detect the truncated sequence of SEA deletion and the normal sequence within deletion range simultaneously for all these samples with the same detecting system.The genotype of α-thalassemia SEA deletion was accurately acquired according to the positive result of fluorescent PCR combined with the Ct value difference.Meanwhile,the accuracy and feasibility of this method were verified and analyzed by parallely detecting these samples with routine gapPCR for α-thalassemia SEA deletion.The genotype could be obtained according to PCR amplification and agarose gel electrophoresis.Results Two amplification efficiencies of the optimized dual TaqMan real-time fluorescence nested PCR system established in this study were both close to 100% with the slops of -3.153 and -3.182,respectively.The results of 50 samples of α-thalassemia SEA deletion with genotyping results showed that this method could not only realize rapid diagnosis,but also effectively avoid false negative or false-positive misdiagnosis by accurately determine the external contamination in the sample.Among 100 blood samples,eleven samples with SEA deletion were detected respectively and the diagnosis coincidence rate of these two methods was 100%,3 samples with SEA deletion were detected by gap-PCR,but 2 samples with SEA deletion and 1 villi sample with normal genotype but contaminated by SEA were detected by this method among 7 fetal samples.Conclusions A double TaqMan real-time fluorescence nested PCR method for α-thalassemia SEA deletion was developed.The method is a rapid and reliable test with simple operation,and is suitable for large-scale population screening and routine molecular diagnosis.