Development of a Melting Curve-Based Allele-Specific PCR of Apolipoprotein E (APOE) Genotyping Method for Genomic DNA, Guthrie Blood Spot, and Whole Blood

PLoS One. 2016 Apr 14;11(4):e0153593. doi: 10.1371/journal.pone.0153593. eCollection 2016.

Abstract

Genetic polymorphisms of apolipoprotein E (APOE) are associated with various health conditions and diseases, such as Alzheimer's disease, cardiovascular diseases, type 2 diabetes, etc. Hence, genotyping of APOE has broad applications in biomedical research and clinical settings, particularly in the era of precision medicine. The study aimed to develop a convenient and accurate method with flexible throughput to genotype the APOE polymorphisms. A melting curve-based allele-specific PCR method was developed to genotype two single nucleotide polymorphisms (SNPs) of APOE, i.e. rs429358 at codon 112 and rs7412 at codon 158. These two SNPs determine the genotype of APOE2, E3, and E4. PCR-based Sanger sequencing was used as the reference method for APOE genotyping. A 100% concordance rate was obtained in 300 subjects between the melting curve-based allele-specific PCR method and the Sanger sequencing method. This method was applied to a genetic association analysis of APOE and schizophrenia consisting of 711 patients with schizophrenia and 665 control subjects from Taiwan. However, no significant differences in the allele and genotype frequencies were detected between these two groups. Further experiments showed that DNA dissolved from blood collected on Guthrie filter paper and total blood cell lysate without DNA extraction can be used in the melting curve-based allele-specific PCR method. Thus, we suggest that this is a fast, accurate and robust APOE genotyping method with a flexible throughput and suitable for DNA template from different preparations. This convenient method shall meet the different needs of various research and clinical laboratories.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Apolipoproteins E / genetics*
  • Blood Specimen Collection / methods
  • DNA / blood
  • DNA / chemistry
  • DNA / genetics*
  • Dried Blood Spot Testing / methods
  • Gene Frequency
  • Genotype
  • Genotyping Techniques / methods*
  • Humans
  • Nucleic Acid Denaturation
  • Polymerase Chain Reaction / methods*
  • Polymorphism, Single Nucleotide
  • Reproducibility of Results
  • Schizophrenia / blood
  • Schizophrenia / diagnosis
  • Schizophrenia / genetics
  • Sensitivity and Specificity

Substances

  • Apolipoproteins E
  • DNA

Grants and funding

The study was supported by grants CMRPG3C1771 and CMRPG3C1772 from Chang Gung Memorial Hospital-Linkou, Taiwan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.