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

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....

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Autores principales: Rasmussen, Astrid, Hildonen, Mathis, Vissing, John, Duno, Morten, Tümer, Zeynep, Birkedal, Ulf
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9222588/
https://www.ncbi.nlm.nih.gov/pubmed/35741732
http://dx.doi.org/10.3390/genes13060970
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author Rasmussen, Astrid
Hildonen, Mathis
Vissing, John
Duno, Morten
Tümer, Zeynep
Birkedal, Ulf
author_facet Rasmussen, Astrid
Hildonen, Mathis
Vissing, John
Duno, Morten
Tümer, Zeynep
Birkedal, Ulf
author_sort Rasmussen, Astrid
collection PubMed
description 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.
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spelling pubmed-92225882022-06-24 High Resolution Analysis of DMPK Hypermethylation and Repeat Interruptions in Myotonic Dystrophy Type 1 Rasmussen, Astrid Hildonen, Mathis Vissing, John Duno, Morten Tümer, Zeynep Birkedal, Ulf Genes (Basel) Article 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. MDPI 2022-05-28 /pmc/articles/PMC9222588/ /pubmed/35741732 http://dx.doi.org/10.3390/genes13060970 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Rasmussen, Astrid
Hildonen, Mathis
Vissing, John
Duno, Morten
Tümer, Zeynep
Birkedal, Ulf
High Resolution Analysis of DMPK Hypermethylation and Repeat Interruptions in Myotonic Dystrophy Type 1
title High Resolution Analysis of DMPK Hypermethylation and Repeat Interruptions in Myotonic Dystrophy Type 1
title_full High Resolution Analysis of DMPK Hypermethylation and Repeat Interruptions in Myotonic Dystrophy Type 1
title_fullStr High Resolution Analysis of DMPK Hypermethylation and Repeat Interruptions in Myotonic Dystrophy Type 1
title_full_unstemmed High Resolution Analysis of DMPK Hypermethylation and Repeat Interruptions in Myotonic Dystrophy Type 1
title_short High Resolution Analysis of DMPK Hypermethylation and Repeat Interruptions in Myotonic Dystrophy Type 1
title_sort high resolution analysis of dmpk hypermethylation and repeat interruptions in myotonic dystrophy type 1
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9222588/
https://www.ncbi.nlm.nih.gov/pubmed/35741732
http://dx.doi.org/10.3390/genes13060970
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