A novel loop-mediated isothermal amplification-based genotyping method and its application for identifying proprotein convertase subtilisin/kexin type 9 variants in familial hypercholesterolemia

Biochim Biophys Acta Gen Subj. 2022 Feb;1866(2):130063. doi: 10.1016/j.bbagen.2021.130063. Epub 2021 Nov 27.

Abstract

Background: Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a key role in regulating low-density lipoprotein levels in plasma. While PCSK9 variants are causatively associated with familial hypercholesterolemia (FH), additional genotyping methods for FH targeting PCSK9 variants are required in a clinical setting. Loop-mediated isothermal amplification (LAMP) is a unique amplification method that amplifies a target gene under isothermal conditions (60-65 °C). However, a robust standardized method has not yet been established for LAMP-based genetic screening tests for genetic diseases, including FH. The present study aimed to develop a novel modification of the LAMP method designed to genotype single nucleotide variants (SNVs) and to apply it for the detection of PCSK9 variants.

Methods: Using short quenching probes (≤ 10 nucleotides) for the loop structures of LAMP amplicons, accurate detection of SNVs was verified separately for each allele, without any additional procedures, within 3 h. The diagnostic performance of this method in detecting PCSK9 variants was validated in FH patients.

Results: All PCSK9 variants tested via conventional sequencing in FH patients were successfully detected using this novel LAMP method.

Conclusions: We developed a LAMP-based genotyping method to detect PCSK9 variants in FH. Compared to conventional sequencing, our genotyping method is relatively convenient and time-efficient and is suitable for the screening of FH in clinical settings. Future studies on various genes are also warranted.

Keywords: Cardiovascular disease (CVD); Familial hypercholesterolemia; Genetic test; Single nucleotide polymorphism (SNP).

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Female
  • Genotype
  • Genotyping Techniques / methods
  • Humans
  • Hyperlipoproteinemia Type II* / blood
  • Hyperlipoproteinemia Type II* / genetics
  • Male
  • Middle Aged
  • Molecular Diagnostic Techniques
  • Nucleic Acid Amplification Techniques* / methods
  • Polymorphism, Single Nucleotide
  • Proprotein Convertase 9* / genetics

Substances

  • Proprotein Convertase 9
  • PCSK9 protein, human

Supplementary concepts

  • LAMP assay