Method for detecting fetus father DNA mononucleotide difference from plasma in pregnaut women

Abstract

The invention relates to the method used to detect embryo paternal line DNA mononucleotide difference from pregnant woman's plasma. It includes the following steps: conventional PCR amplification, single basic group extending reaction marking target sequence, bead separating target sequence, and biologic bar code signal amplification and detecting. Its advantages are that it has low cost and is practicable; it can detect mononucleotide mutation and polymorphism in embryo paternal line DNA, and embryo DNA content.

Description

(1) Technical field [0001] The invention relates to a DNA detection method, in particular to a method for detecting the single nucleotide difference of free DNA. (2) Technical background [0002] With the transformation of my country's population and disease patterns, the problem of birth defects has become increasingly prominent, and has become the main cause of newborn and infant deaths, and disability of children and adults in my country. According to the statistics of the Ministry of Health, the incidence of birth defects is about 13.05‰, of which the proportion of birth defects caused by genetic factors is as high as 25%. There is no effective treatment for hereditary birth defects. At present, prenatal diagnosis can be used to effectively avoid the birth of children, which is conducive to prenatal and postnatal care and improving the quality of the population. [0003] The traditional amniocentesis and chorionic villus extraction are the prenatal diagnostic techniques...

AI Technical Summary

Problems solved by technology

However, this method has the following shortcomings: as we all know, the influence of detection reliability is determined by the type of nucleotide difference, the content of target DNA in the sample, and the ratio between target DNA and background DNA.

The technology platform is based on single base extension reaction (SBER) with high specificity and matrix assisted laser desorption ionization / time-of-flight mass spectrometry (matrix assisted laser desorption ionization-time offlight MS, MALDI-TOF- MS), will have the potential to be applied to non-invasive prenatal diagnosis, but this method has the following disadvantages: 1) When the concentration of mutant DNA is lower than 1% of the wild-type DNA concentration, the single base extension reaction may appear independent of template Amplification, using SBER technology to detect fetal DNA mutations in maternal plasma, especially serum, may cause misdiagnosis, so the ratio of fetal DNA to total plasma DNA seriously affects the diagnostic results of this method; 2) The instrument is expensive and the detection cost is high

Due to the above disadvantages, the application of this method in maternal plasma is limited