PCR/LDR/capillary electrophoresis for detection of single-nucleotide differences between fetal and maternal DNA in maternal plasma

Background The discovery of fetal DNA in maternal plasma has opened up an approach for noninvasive diagnosis. We have now assessed the possibility of detecting single-nucleotide differences between fetal and maternal DNA in maternal plasma by polymerase chain reaction (PCR)/ligase detection reaction((LDR)/capillary electrophoresis. Methods PCR/LDR/capillary electrophoresis was applied to detect the genotype of c.454-397T>gene (ESR1) from experimental DNA models of maternal plasma at different sensitivity levels and 13 maternal plasma samples.alpha C in estrogen receptor. Results (1) Our results demonstrated that the technique could discriminate low abundance single-nucleotide mutation with a mutant/normal allele ratio up to 1 : 10 000. (2) Examination of ESR1 c.454-397T>C genotypes by using the method of restriction fragment length analysis was performed in 25 pregnant women, of whom 13 pregnant women had homozygous genotypes. The c.454-397T>C genotypes of paternally inherited fetal DNA in maternal plasma of these 13 women were detected by PCR/LDR/capillary electrophoresis, which were accordant with the results of umbilical cord blood. Conclusions PCR/LDR/capillary electrophores is has very high sensitivity to distinguish low abundance single nucleotide differences and can discriminate point mutations and sin le-nucleotide polymorphisms(SNPS) of 9 paternally inherited fetal DNA in maternal plasma. Copyright (C) 2009 John Wiley & Sons, Ltd.