landfeldt-et-al-2025-in-response-to-gulcin-akinci-s-and-haluk-topaloglu-s-letter-regarding-our-article-predictors-of.pdf — page 1

In response to Gulcin Akinci’s and Haluk
Topaloglu’s letter regarding our article
“Predictors of loss of ambulation in
Duchenne muscular dystrophy: A
systematic review and meta-analysis”
We thank Dr Gulcin Akinci and Dr Haluk Topaloglu for
their comments1 on our literature review.2 The concern is
that current evidence supports that deletions amenable to
exon 53 skipping are not associated with later loss of ambu-
lation (LoA) compared with other deletions in DMD.
Certainly, we did mention this in the Results section
(DMD mutations and genetic modiﬁers) and in Table 2.
We stated that Servais et al.3 found that the mean age at
LoA was estimated at 8.7 years for participants with exon
53 skip-amenable mutations, compared with 10.4 for those
with mutations not treatable by exon 53 skipping (p =
0.031), and 10.7 years for those with deletions not treatable
by exon 53 skipping (p = 0.011), suggesting that deletions
amenable to exon 53 skipping are associated with earlier
LoA compared to other deletions in DMD. However, we
believe that the confusion arises from an unforeseen error
in the summary of the evidence in the Discussion section
(as well as Figure 4 and Figure 5), where we indeed errone-
ously stated that mutations amenable to exon 53 skipping are
associated with later LoA. This mistake has been corrected
in an Erratum4 to the published article.
It is worth noting that two publications mentioned by Dr
Gulcin Akinci and Dr Haluk Topaloglu were not included
in our SLR as they did not meet the inclusion criteria (the
ﬁrst article5 did not report results for LoA as an outcome,
and the second6 was published after our search period).
We are grateful that this mistake was brought to our
attention and thank Dr Gulcin Akinci and Dr Haluk
Topaloglu again for their letter.
E Landfeldt
IQVIA, Stockholm, Sweden
erik.landfeldt@iqvia.com
A Alemán
Division of Neurology, Department of Pediatrics,
Children’s Hospital of Eastern Ontario, Research Institute,
University of Ottawa, Ottawa, ON, Canada
Division of Neurology, Department of Medicine, The
Ottawa Hospital, Brain and Mind Research Institute,
University of Ottawa, Ottawa, Canada
S Abner
IQVIA, London, UK
R Zhang
PTC Therapeutics Sweden AB, Askim, Sweden
C Werner
PTC Therapeutics Germany GmbH, Frankfurt, Germany
I Tomazos
PTC Therapeutics Inc, Warren, NJ, USA
N Ferizovic
IQVIA, London, UK
H Lochmüller
Division of Neurology, Department of Pediatrics,
Children’s Hospital of Eastern Ontario, Research Institute,
University of Ottawa, Ottawa, ON, Canada
Division of Neurology, Department of Medicine, The
Ottawa Hospital, Brain and Mind Research Institute,
University of Ottawa, Ottawa, Canada
Department of Neuropediatrics and Muscle Disorders,
Medical Center, University of Freiburg, Faculty of
Medicine, Freiburg, Germany
J Kirschner
Department of Neuropediatrics and Muscle Disorders,
Medical Center, University of Freiburg, Faculty of
Medicine, Freiburg, Germany
Statements and declarations
Funding
The authors received no ﬁnancial support for the research, author-
ship, and/or publication of this article.
Declaration of conﬂicting interests
The authors declared no potential conﬂicts of interest with respect
to the research, authorship, and/or publication of this article.
Creative Commons Non Commercial CC BY-NC: This article is distributed under the terms of the Creative Commons Attribution-
NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and
distribution of the work without further permission provided the original work is attributed as speciﬁed on the SAGE and Open Access page (https://us.
sagepub.com/en-us/nam/open-access-at-sage).
Letter to the Editor
Journal of Neuromuscular Diseases
2025, Vol. 12(1): 151–152
© The Author(s) 2025
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DOI: 10.1177/22143602241312519
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