Table of Contents
Journal of Neurodegenerative Diseases
Volume 2013, Article ID 857564, 8 pages
Research Article

Simple Repeat-Primed PCR Analysis of the Myotonic Dystrophy Type 1 Gene in a Clinical Diagnostics Environment

1Diagnostic Genetics, LabPlus, Auckland City Hospital, P.O. Box 110031, Auckland 1148, New Zealand
2School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand

Received 31 March 2013; Revised 18 September 2013; Accepted 19 September 2013

Academic Editor: Eng King Tan

Copyright © 2013 Philippa A. Dryland et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Myotonic dystrophy type 1 is an autosomal dominant neuromuscular disorder that is caused by the expansion of a CTG trinucleotide repeat in the DMPK gene. The confirmation of a clinical diagnosis of DM-1 usually involves PCR amplification of the CTG repeat-containing region and subsequent sizing of the amplification products in order to deduce the number of CTG repeats. In the case of repeat hyperexpansions, Southern blotting is also used; however, the latter has largely been superseded by triplet repeat-primed PCR (TP-PCR), which does not yield a CTG repeat number but nevertheless provides a means of stratifying patients regarding their disease severity. We report here a combination of forward and reverse TP-PCR primers that allows for the simple and effective scoring of both the size of smaller alleles and the presence or absence of expanded repeat sequences. In addition, the CTG repeat-containing TP-PCR forward primer can target both the DM-1 and Huntington disease genes, thereby streamlining the work flow for confirmation of clinical diagnoses in a diagnostic laboratory.