Duchenne Muscular Dystrophy and Early Onset Hypertrophic Cardiomyopathy associated with Mutations in Dystrophin and Hypertrophic Cardiomyopathy-Associated Genes

2020 ◽  
Author(s):  
Liam Aspit ◽  
Noga Arwas ◽  
Aviva Levitas ◽  
Hanna Krymko ◽  
Yoram Etzion ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Hypertrophic Cardiomyopathy ◽  
Muscular Dystrophy ◽  
Early Onset ◽  
De Novo ◽  
Genetic Diagnosis ◽  
Dystrophin Gene ◽  
Whole Exome ◽  
Rare Phenotype ◽  
Muscular Damage

AbstractDuchenne muscular dystrophy (DMD) is a progressive muscular damage disorder caused by mutations in dystrophin gene. Cardiomyopathy may first be evident after 10 years of age and increases in incidence with age. We present a boy diagnosed at 18 months with a rare phenotype of DMD in association with early-onset hypertrophic cardiomyopathy (HCM). The cause of DMD is a deletion of exons 51–54 of dystrophin gene. The cause of HCM was verified by whole exome sequencing. Novel missense variations in two genes: MAP2K5 inherited from the mother and ACTN2 inherited from the father, or de novo. The combination of MAP2K5, ACTN2, and dystrophin mutations, could be causing the HCM in our patient. This is the second patient diagnosed, at relatively young age, with DMD and HCM, with novel variations in genes known to cause HCM. This study demonstrates the need for genetic diagnosis to elucidate the underlying pathology of HCM.

scholarly journals Genetic analysis of 62 Chinese families with Duchenne muscular dystrophy and strategies of prenatal diagnosis in a single center

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Jingjing Zhang ◽  
Dingyuan Ma ◽  
Gang Liu ◽  
Yuguo Wang ◽  
An Liu ◽  
...  
Keyword(s):  
Prenatal Diagnosis ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
De Novo ◽  
Clinical Symptoms ◽  
Perinatal Care ◽  
Genetic Diagnosis ◽  
Point Mutations ◽  
Inherited Disease ◽  
Positive Results

Abstract Background Duchenne muscular dystrophy (DMD) is a severe X-linked recessive neuromuscular disorder. Patients with DMD usually have severe and fatal symptoms, including progressive irreversible muscle weakness and atrophy complicated with gastrocnemius muscle pseudohypertrophy. DMD is caused by mutations in the dystrophin-encoding DMD gene, including large rearrangements and point mutations. This retrospective study was aimed at supplying information on our 4-year clinical experience of DMD genetic and prenatal diagnosis at the Department of Prenatal Diagnosis in Women’s Hospital of Nanjing Medical University. Methods Multiplex ligation-dependent probe amplification (MLPA) was used to detect the exon deletions or duplications. And Ion AmpliSeq™ panel for inherited disease was used as the next-generation sequencing (NGS) method to identify the point mutations in exons of DMD gene, but the introns were not sequenced. Results In this study, the large deletions and duplications of DMD gene were detected in 32 (51.6%) of the 62 families, while point mutations were detected in 20 families (32.3%). The remaining 10 families with a negative genetic diagnosis need to be reevaluated for clinical symptoms or be detected by other molecular methods. Notably, six novel mutations were identified, including c.412A > T(p.Lys138*), c.2962delT(p.Ser988Leufs*16), c.6850dupA (p.Ser2284Lysfs*7), c.5139dupA (p.Glu 1714Argfs*5), c.6201_6203delGCCins CCCA(p.Val2069Cysfs*14) and c.10705A > T (p.Lys3569*). In 52 families with positive results, 45 mothers (86.5%) showed positive results during carrier testing and de novo mutations arose in 7 probands. The prenatal diagnosis was offered to 34 fetuses whether the pregnant mother was a carrier or not. As a result, eight male fetuses were affected, three female fetuses were carriers, and the remaining fetuses had no pathogenic mutation. Conclusions This study reported that MLPA and NGS could be used for screening the DMD gene mutations. Furthermore, the stepwise procedure of prenatal diagnosis of DMD gene was shown in our study, which is important for assessing the mutation type of fetuses and providing perinatal care in DMD high-risk families.

scholarly journals Early Diagnosis and Treatment – The Use of Ataluren in the Effective Management of Duchenne Muscular Dystrophy

2018 ◽  
Vol 13 (1) ◽  
pp. 31
Author(s):  
Eugenio Mercuri ◽  
Ros Quinlivan ◽  
Sylvie Tuffery-Giraud
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
De Novo ◽  
Point Mutations ◽  
Dystrophin Gene ◽  
Phase Iii ◽  
Female Carrier ◽  
De Novo Mutations ◽  
Nonsense Mutations ◽  
Disease Modifying

The understanding of the natural history of Duchenne muscular dystrophy (DMD) is increasing rapidly and new treatments are emerging that have the potential to substantially improve the prognosis for patients with this disabling and life-shortening disease. For many, however, there is a long delay between the appearance of symptoms and DMD diagnosis, which reduces the possibility of successful treatment. DMD results from mutations in the large dystrophin gene of which one-third are de novo mutations and two-thirds are inherited from a female carrier. Roughly 75% of mutations are large rearrangements and 25% are point mutations. Certain deletions and nonsense mutations can be treated whereas many other mutations cannot currently be treated. This emphasises the need for early genetic testing to identify the mutation, guide treatment and inform genetic counselling. Treatments for DMD include corticosteroids and more recently, ataluren has been approved in Europe, the first disease-modifying therapy for treating DMD caused by nonsense mutations. The use of ataluren in DMD is supported by positive results from phase IIb and phase III studies in which the treatment produced marked improvements in the 6-minute walk test, timed function tests such as the 10 m walk/run test and the 4-stair ascent/descent test compared with placebo. In these trials, ataluren was well tolerated and adverse event profiles were similar to placebo. As such disease-modifying treatments become more widely available, the outlook for children with DMD will improve but physicians must be aware of the disease, rapidly initiate testing where it is suspected and promptly begin appropriate treatment.

Pseudo-metabolic presentation in a Duchenne muscular dystrophy symptomatic carrier with ‘de novo’ duplication of dystrophin gene

2001 ◽  
Vol 11 (5) ◽  
pp. 494-498 ◽  
Author(s):  
Norma Beatriz Romero ◽  
Pascale De Lonlay ◽  
Stéphane Llense ◽  
France Leturcq ◽  
Guy Touati ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
De Novo ◽  
Dystrophin Gene ◽  
Symptomatic Carrier

scholarly journals Evaluating the potential of novel genetic approaches for the treatment of Duchenne muscular dystrophy

2021 ◽  
Author(s):  
Vratko Himič ◽  
Kay E. Davies
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Structural Integrity ◽  
Viral Vector ◽  
Exon Skipping ◽  
Dystrophin Gene ◽  
Pharmacological Treatments ◽  
Genetic Sequencing ◽  
Reading Frame ◽  
Target Effects

AbstractDuchenne muscular dystrophy (DMD) is an X-linked progressive muscle-wasting disorder that is caused by a lack of functional dystrophin, a cytoplasmic protein necessary for the structural integrity of muscle. As variants in the dystrophin gene lead to a disruption of the reading frame, pharmacological treatments have only limited efficacy; there is currently no effective therapy and consequently, a significant unmet clinical need for DMD. Recently, novel genetic approaches have shown real promise in treating DMD, with advancements in the efficacy and tropism of exon skipping and surrogate gene therapy. CRISPR-Cas9 has the potential to be a ‘one-hit’ curative treatment in the coming decade. The current limitations of gene editing, such as off-target effects and immunogenicity, are in fact partly constraints of the delivery method itself, and thus research focus has shifted to improving the viral vector. In order to halt the loss of ambulation, early diagnosis and treatment will be pivotal. In an era where genetic sequencing is increasingly utilised in the clinic, genetic therapies will play a progressively central role in DMD therapy. This review delineates the relative merits of cutting-edge genetic approaches, as well as the challenges that still need to be overcome before they become clinically viable.

scholarly journals The administration of antisense oligonucleotide golodirsen reduces pathological regeneration in patients with Duchenne muscular dystrophy

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Dominic Scaglioni ◽  
Francesco Catapano ◽  
Matthew Ellis ◽  
Silvia Torelli ◽  
Darren Chambers ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Antisense Oligonucleotide ◽  
De Novo ◽  
Exon Skipping ◽  
Significant Negative Correlation ◽  
Entire Cohort ◽  
Associated Proteins ◽  
Analysis Platform ◽  
Dystrophin Protein

AbstractDuring the last decade, multiple clinical trials for Duchenne muscular dystrophy (DMD) have focused on the induction of dystrophin expression using different strategies. Many of these trials have reported a clear increase in dystrophin protein following treatment. However, the low levels of the induced dystrophin protein have raised questions on its functionality. In our present study, using an unbiased, high-throughput digital image analysis platform, we assessed markers of regeneration and levels of dystrophin associated protein via immunofluorescent analysis of whole muscle sections in 25 DMD boys who received 48-weeks treatment with exon 53 skipping morpholino antisense oligonucleotide (PMO) golodirsen. We demonstrate that the de novo dystrophin induced by exon skipping with PMO golodirsen is capable of conferring a histological benefit in treated patients with an increase in dystrophin associated proteins at the dystrophin positive regions of the sarcolemma in post-treatment biopsies. Although 48 weeks treatment with golodirsen did not result in a significant change in the levels of fetal/developmental myosins for the entire cohort, there was a significant negative correlation between the amount of dystrophin and levels of regeneration observed in different biopsy samples. Our results provide, for the first time, evidence of functionality of induced dystrophin following successful therapeutic intervention in the human.

scholarly journals Autophagy in the heart is enhanced and independent of disease progression in mus musculus dystrophinopathy models

2019 ◽  
Vol 8 ◽  
pp. 204800401987958
Author(s):  
HR Spaulding ◽  
C Ballmann ◽  
JC Quindry ◽  
MB Hudson ◽  
JT Selsby
Keyword(s):  
Skeletal Muscle ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Disease Progression ◽  
Gene Mutations ◽  
Dystrophin Gene ◽  
Mdx Mice ◽  
Dystrophin Deficiency ◽  
Muscle Wasting Disease ◽  
Dystrophin Protein

Background Duchenne muscular dystrophy is a muscle wasting disease caused by dystrophin gene mutations resulting in dysfunctional dystrophin protein. Autophagy, a proteolytic process, is impaired in dystrophic skeletal muscle though little is known about the effect of dystrophin deficiency on autophagy in cardiac muscle. We hypothesized that with disease progression autophagy would become increasingly dysfunctional based upon indirect autophagic markers. Methods Markers of autophagy were measured by western blot in 7-week-old and 17-month-old control (C57) and dystrophic (mdx) hearts. Results Counter to our hypothesis, markers of autophagy were similar between groups. Given these surprising results, two independent experiments were conducted using 14-month-old mdx mice or 10-month-old mdx/Utrn± mice, a more severe model of Duchenne muscular dystrophy. Data from these animals suggest increased autophagosome degradation. Conclusion Together these data suggest that autophagy is not impaired in the dystrophic myocardium as it is in dystrophic skeletal muscle and that disease progression and related injury is independent of autophagic dysfunction.

scholarly journals The Interplay of Mitophagy and Inflammation in Duchenne Muscular Dystrophy

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 648
Author(s):  
Andrea L. Reid ◽  
Matthew S. Alexander
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Mitochondrial Dysfunction ◽  
Disease Onset ◽  
Exon Skipping ◽  
Dystrophin Gene ◽  
Muscle Disease ◽  
Mitochondrial Morphology ◽  
Gene Therapies ◽  
Dystrophin Protein

Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disease caused by a pathogenic disruption of the DYSTROPHIN gene that results in non-functional dystrophin protein. DMD patients experience loss of ambulation, cardiac arrhythmia, metabolic syndrome, and respiratory failure. At the molecular level, the lack of dystrophin in the muscle results in myofiber death, fibrotic infiltration, and mitochondrial dysfunction. There is no cure for DMD, although dystrophin-replacement gene therapies and exon-skipping approaches are being pursued in clinical trials. Mitochondrial dysfunction is one of the first cellular changes seen in DMD myofibers, occurring prior to muscle disease onset and progresses with disease severity. This is seen by reduced mitochondrial function, abnormal mitochondrial morphology and impaired mitophagy (degradation of damaged mitochondria). Dysfunctional mitochondria release high levels of reactive oxygen species (ROS), which can activate pro-inflammatory pathways such as IL-1β and IL-6. Impaired mitophagy in DMD results in increased inflammation and further aggravates disease pathology, evidenced by increased muscle damage and increased fibrosis. This review will focus on the critical interplay between mitophagy and inflammation in Duchenne muscular dystrophy as a pathological mechanism, as well as describe both candidate and established therapeutic targets that regulate these pathways.

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