Fast Temperature-Gradient COLD PCR for the enrichment of the paternally inherited SNPs in cell free fetal DNA; an application to non-invasive prenatal diagnosis of β-thalassaemia

• Published in: PloS one Vol. 13; no. 7; p. e0200348
• Main Authors: Byrou, Stefania, Makrigiorgos, G Mike, Christofides, Agathoklis, Kallikas, Ioannis, Papasavva, Thessalia, Kleanthous, Marina
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 25-07-2018; Public Library of Science (PLoS)
• Subjects: Alleles; Assaying; beta-Thalassemia - diagnosis; beta-Thalassemia - genetics; Biology and Life Sciences; Blood diseases; Cancer; Cell-Free Nucleic Acids - analysis; Cell-Free Nucleic Acids - blood; Cold; Congenital diseases; Denaturation; Deoxyribonucleic acid; DNA; Drug dosages; Female; Fetuses; Gene Frequency; Genetic testing; Genetics; Genotyping Techniques; Haplotypes; Heterozygosity; Humans; Medical diagnosis; Medicine; Medicine and Health Sciences; Methods; Mutation; Neurology; Paternal Inheritance; Plasma; Polymerase chain reaction; Polymerase Chain Reaction - methods; Polymorphism, Single Nucleotide; Pregnancy; Prenatal diagnosis; Prenatal Diagnosis - methods; Research and Analysis Methods; Risk analysis; Sensitivity and Specificity; Single-nucleotide polymorphism; Temperature; Temperature effects; Thalassemia; Villus; Cyprus
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0200348

To develop a sensitive, specific, simple, cost-effective and reproducible platform for the non-invasive prenatal detection of paternally inherited alleles for β-thalassaemia. The development of such an assay is of major significance in order to replace currently-applied invasive methods containing inherent fetal loss risks.
We present a fast Temperature-Gradient Co-amplification at Lower Denaturation Temperature Polymerase Chain Reaction (fast TG COLD PCR) methodology for the detection of the paternally-inherited fetal alleles in maternal plasma. Two single-nucleotide polymorphisms (SNPs), rs7480526 (G/T) and rs968857 (G/A) that are located on the β-globin gene cluster and exhibit a high degree of heterozygosity in the Cypriot population were selected for evaluation. Seventeen maternal plasma samples from pregnancies at risk for β-thalassemia were analysed for the selected SNPs using the novel fast TG COLD PCR assay.
Using fast TG COLD PCR, the paternally inherited allele in cell free fetal DNA was correctly determined for all the 17 maternal plasma samples tested, showing full agreement with the Chorionic Villus Sampling (CVS) analysis.
Our findings are encouraging and demonstrate the efficiency and sensitivity of fast TG COLD PCR in detecting the minor paternally-inherited fetal alleles in maternal plasma for the development of a NIPD assay for β-thalassaemia.