High Resolution Analysis of DMPK Hypermethylation and Repeat Interruptions in Myotonic Dystrophy Type 1

Astrid Rasmussen, Mathis Hildonen, John Vissing, Morten Duno, Zeynep Tümer*, Ulf Birkedal

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

10 Citationer (Scopus)
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Abstract

Myotonic dystrophy type 1 (DM1) is a multisystemic neuromuscular disorder caused by the expansion of a CTG repeat in the 3-UTR of DMPK, which is transcribed to a toxic gain-of-function RNA that affects splicing of a range of genes. The expanded repeat is unstable in both germline and somatic cells. The variable age at disease onset and severity of symptoms have been linked to the inherited CTG repeat length, non-CTG interruptions, and methylation levels flanking the repeat. In general, the genetic biomarkers are investigated separately with specific methods, making it tedious to obtain an overall characterisation of the repeat for a given individual. In the present study, we employed Oxford nanopore sequencing in a pilot study to simultaneously determine the repeat lengths, investigate the presence and nature of repeat interruptions, and quantify methylation levels in the regions flanking the CTG-repeats in four patients with DM1. We determined the repeat lengths, and in three patients, we observed interruptions which were not detected using repeat-primed PCR. Interruptions may thus be more common than previously anticipated and should be investigated in larger cohorts. Allele-specific analyses enabled characterisation of aberrant methylation levels specific to the expanded allele, which greatly increased the sensitivity and resolved cases where the methylation levels were ambiguous.

OriginalsprogEngelsk
Artikelnummer970
TidsskriftGenes
Vol/bind13
Udgave nummer6
Antal sider12
ISSN2073-4425
DOI
StatusUdgivet - 2022

Bibliografisk note

Funding Information:
Funding: This research was funded by Jascha Fonden (grant number 2021-0131).

Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.

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