Fast Assays to Detect Interruptions in CTG.CAG Repeat Expansions

Methods Mol Biol. 2020:2056:11-23. doi: 10.1007/978-1-4939-9784-8_2.

Abstract

Different interrupted repeat expansions have been found in several trinucleotide repeat (TNR) diseases such as fragile X syndrome (FXS), spinocerebellar ataxias (SCAs), and myotonic dystrophies (DMs). Their origins and roles remain poorly understood, especially in myotonic dystrophy type 1 (DM1). We present here the triplet repeat primed polymerase chain reaction (TP-PCR) and restriction enzyme-digested PCR to detect and identify interrupted triplet repeat alleles in DM1. TP-PCR consists of a PCR amplification using a fluoresceinated (FAM) primer flanking the repeat region and a primer pair in CTG.CAG repeats. A detailed analysis of interrupted triplet repeat tracts is essential to fully understand the role of interruptions in the pathogenesis and molecular mechanisms observed in TNR diseases.

Keywords: Interrupted repeat expansions; Myotonic dystrophy type 1; Polymerase chain reaction; Restriction enzyme-digested PCR; Trinucleotide repeats; Triplet repeat prime PCR (TP-PCR).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA Restriction Enzymes / metabolism
  • Fluorescein / chemistry
  • Genetic Predisposition to Disease
  • Humans
  • Myotonic Dystrophy / genetics*
  • Oligonucleotides / chemistry
  • Polymerase Chain Reaction / methods*
  • Time Factors
  • Trinucleotide Repeat Expansion*

Substances

  • Oligonucleotides
  • DNA Restriction Enzymes
  • Fluorescein