Symptoms Of Duchenne Muscular Dystrophy Research Articles

Novel mutation leading to splice donor loss in a conserved site of DMD gene causes Duchenne muscular dystrophy with cryptorchidism

BackgroundAs one of the most common congenital abnormalities in male births, cryptorchidism has been found to have a polygenic aetiology according to previous studies of common variants. However, little is...

Computer-Aided Diagnosis of Duchenne Muscular Dystrophy Based on Texture Pattern Recognition on Ultrasound Images Using Unsupervised Clustering Algorithms and Deep Learning

ObjectiveThe feasibility of using deep learning in ultrasound imaging to predict the ambulatory status of patients with Duchenne muscular dystrophy (DMD) was previously explored for the first time. The present study further used clustering algorithms for the texture reconstruction of ultrasound images of DMD data sets and analyzed the difference in echo intensity between disease stages. Methodsk-means (Kms) and fuzzy c-means (FCM) clustering algorithms were used to reconstruct the DMD data-set textures. Each image was reconstructed using seven texture-feature categories, six of which were used as the primary analysis items. The task of automatically identifying the ambulatory function and DMD severity was performed by establishing a machine-learning model. ResultsThe experimental results indicated that the Gaussian Naïve Bayes and k-nearest neighbors classification models achieved an accuracy of 86.78% in ambulatory function classification. The decision-tree model achieved an identification accuracy of 83.80% in severity classification. A deep convolutional neural network model was established as the main structure of the deep-learning model while automatic auxiliary interpretation tasks of ambulatory function and severity were performed, and data augmentation was used to improve the recognition performance of the trained model. Both the visual geometry group (VGG)-16 and VGG-19 models achieved 98.53% accuracy in ambulatory-function classification. The VGG-19 model achieved 92.64% accuracy in severity classification. ConclusionRegarding the overall results, the Kms and FCM clustering algorithms were used in this study to reconstruct the characteristic texture of the gastrocnemius muscle group in DMD, which was indeed helpful in quantitatively analyzing the deterioration of the gastrocnemius muscle group in patients with DMD at different stages. Subsequent combination of machine-learning and deep-learning technologies can automatically and accurately assist in identifying DMD symptoms and tracking DMD deterioration for long-term observation.

Detecting early signs in Duchenne muscular dystrophy: comprehensive review and diagnostic implications.

Despite the early onset of clinical signs suggestive of Duchenne muscular dystrophy (DMD), a diagnosis is often not made until four years of age or older, with a diagnostic delay of up to two years from the appearance of the first symptoms. As disease-modifying therapies for DMD become available that are ideally started early before irreversible muscle damage occurs, the importance of avoiding diagnostic delay increases. Shortening the time to a definite diagnosis in DMD allows timely genetic counseling and assessment of carrier status, initiation of multidisciplinary standard care, timely initiation of appropriate treatments, and precise genetic mutation characterization to assess suitability for access to drugs targeted at specific mutations while reducing the emotional and psychological family burden of the disease. This comprehensive literature review describes the early signs of impairment in DMD and highlights the bottlenecks related to the different diagnostic steps. In summary, the evidence suggests that the best mitigation strategy for improving the age at diagnosis is to increase awareness of the early symptoms of DMD and encourage early clinical screening with an inexpensive and sensitive serum creatine kinase test in all boys who present signs of developmental delay and specific motor test abnormality at routine pediatrician visits.

Lentiviral Micro-dystrophin Gene Treatment into Late-stage mdx Mice for Duchenne Muscular Dystrophy Disease.

Duchenne Muscular Dystrophy (DMD) results in a deficiency of dystrophin expression in patient muscle fibers, leading to progressive muscle degeneration. Treatment of DMD has undertaken current transformation with the advancement of novel gene therapy and molecular biology techniques, which are secure, well-tolerated, and effective therapeutic approaches. DMD gene therapies have mainly focused on young DMD patients as in vivo animal model trials have been performed in 0-1-month DMD mice. However, it has not yet been answered how micro-dystrophin encoding lentiviral treatment affects Dystrophin expression and DMD symptoms in 10-month mdx mice. We planned to integrate the micro-Dystrophin gene sequence into the muscle cells by viral transfer, using micro-Dystrophin-encoding lentivirus to reduce the dystrophic pathology in late-stage dmd mice. The histopathological and physiological-functional regeneration activities of the lentiviralmicro- Dystrophin gene therapy methods were compared, along with changes in temporal Dystrophin expression and their functionality, toxicity, and gene expression level. Here, we showed that the micro-dystrophin transgene transfers intramuscularly and intraperitoneally in late-stage dmd-mdx-4cv mice restored dystrophin expression in the skeletal and cardiac muscle (p <0.001). Furthermore, motor performance analysis, including hanging and tracking tests, improved statistically significantly after the treatment (p <0.05). Consequently, this study suggests that patients in the late stages of muscular dystrophy can benefit from lentiviral micro-dystrophin gene therapies to present an improvement in dystrophic muscle pathology.

‘It is easier to not allow them to see your disability straight away, to see you as a person’: An Interpretative Phenomenological Analysis of video gaming from the perspectives of men with Duchenne Muscular Dystrophy

Background: Young men with Duchenne Muscular Dystrophy benefit from palliative care that supports their psychosocial needs. Acknowledging the sub-cultures they engage with can support their wellbeing. Anecdotal reports suggest video gaming is a sub-culture engaged with by young men with Duchenne Muscular Dystrophy. Aim: To explore the lived experience of video gaming from the perspective of young men with Duchenne Muscular Dystrophy. Design: Interpretative Phenomenological Analysis approach involving in-depth interviews using a topic guide that focused on social media broadly, with reference to video gaming. Sequential interviewing was undertaken to support participation regarding fatigue and tiredness, symptoms of Duchenne Muscular Dystrophy. Setting/participants: Participants were purposefully recruited from a hospice in the North of England. Twitter was used to support recruitment. Eight young men with Duchenne Muscular Dystrophy were recruited to the study. Results: Five themes were developed; ‘gamer as a shared and accepted identity’, ‘an existential and bodily escapism’, ‘introspection through video gaming’, ‘video gaming as a release’ and ‘when life gives you few choices-video game’. Motivations for engagement with video gaming are diverse and reflective of the situated perspectives of young men with Duchenne Muscular Dystrophy. Conclusions: An awareness of the popular sub-cultures that young men with Duchenne Muscular Dystrophy engage with is key to building a therapeutic alliance, establishing rapport and recognising personhood in interactions between professionals and persons in palliative care settings. This study highlights the value of video gaming, offering professionals valuable insight into its placement in the daily lives of young men with Duchenne Muscular Dystrophy.

Duchenne Muscular Dystrophy Management and Treatment Access Challenges: Case Report

Introduction: Duchenne muscular dystrophy (DMD) is a rare neuromuscular disease that causes muscle weakness with respiratory and cardiac complications. International DMD standard of care guidelines exist, but their implementation and DMD treatment access in the Middle East have historically been challenging. This report highlights sub-optimal management of DMD in the Middle East together with recommendations for best practices, and the first reported use of ataluren, a mutation-specific treatment for nonsense mutation DMD (nmDMD), in this region. Case Presentation: The management of two patients in the United Arab Emirates diagnosed with nonsense mutation DMD is described. Under multidisciplinary care, both patients were treated with corticosteroids as per international DMD standard of care guidelines. Although both patients presented with typical DMD signs/symptoms, one received a genetic diagnosis and treatment relatively late owing to low awareness of the early signs and symptoms of DMD among physicians in the region; delayed genetic diagnosis of DMD hinders early initiation of mutation-specific treatments such as ataluren. Moreover, this patient demonstrated low adherence to the treatment plan, potentially resulting from low DMD awareness and poor understanding of the-risk-benefit of corticosteroids in the patient’s family. In contrast, the other patient was genetically diagnosed early at 25 months, was administered ataluren whilst ambulatory, and demonstrated high adherence to the management plan. Limited expertise in performing motor function assessments and complications with medical insurance for ataluren in the region created additional obstacles in the management of both patients. Conclusions: The contrasting experiences of these patients highlight the high variability of diagnosis and management of DMD in the Middle East. There is a need in the region to boost disease education for both public and professional communities, establish local DMD networks and guidelines, and improve access to treatments to improve the quality of care that patients with DMD receive.

Re-examination of therapeutic management of muscular dystrophies using a vascular smooth muscle-centered approach.

In contrast to the long-standing focus on the pathophysiology of skeletal muscles in the hunt for a cure for Duchenne muscular dystrophy (DMD), we opine that the malfunctioning of dystrophin produced by vascular smooth muscle is a major contributor to the pathology of the illness. We believe that a biological response modifier glucan (BRMG), which has been shown in clinical studies of DMD to boost the expression of vascular smooth muscle dystrophin and provide anti-fibrotic and anti-inflammatory effects, may play a key role in reducing the pathogenesis of DMD. According to the evaluation of biomarkers, this BRMG, which is safe and side-effect-free, reduces the pathogenesis of DMD. We describe the possible mechanisms of action by which this BRMG helps in alleviating the symptoms of DMD by targeting smooth muscle dystrophin, in addition to its advantages over other therapeutic modalities, as well as how it can serve as a valuable adjunct to existing therapies. We suggest that using BRMG adjuncts that target smooth muscle dystrophin would be a potential therapeutic approach that prolongs the lifespan and extends the duration of ambulation from the onset of DMD. Further studies are needed to validate this hypothesis.

Transplantation of Differentiated Tonsil-Derived Mesenchymal Stem Cells Ameliorates Murine Duchenne Muscular Dystrophy via Autophagy Activation.

Skeletal muscles play many important roles in the human body and any malfunction or disorder of the skeletal muscles can lead to a reduced quality of life. Some skeletal dysfunctions are acquired, such as sarcopenia but others are congenital. Duchenne muscular dystrophy (DMD) is one of the most common forms of hereditary muscular dystrophy and is caused by a deficiency of the protein, Dystrophin. Currently, there is no clear treatment for DMD, there are only methods that can alleviate the symptoms of the disease. Mesenchymal stem cells, including tonsil-derived mesenchymal stem cells (TMSCs) have been shown to differentiate into skeletal muscle cells (TMSC-myocyte) and can be one of the resources for the treatment of DMD. Skeletal muscle cell characteristics of TMSC-myocytes have been confirmed through changes in morphology and expression of skeletal muscle markers such as Myogenin, Myf6, and MYH families after differentiation. Based on these characteristics, TMSC-myocytes have been transplanted into mdx mice, a mouse model of DMD, to investigate whether they can help improve the symptoms of DMD. The red fluorescent protein gene was transduced into TMSC (TMSC-R) for tracking transplanted cells. Prior to transplantation (TP), it was confirmed whether TMSC-R-myocytes had the same differentiation potential as TMSC-myocytes. Increased expression of dystrophin and autophagy markers in the TP group compared with the sham group was confirmed in the gastrocnemius muscle 12weeks after TP. These results demonstrate muscle regeneration and functional recovery of mdx via autophagy activation following TMSC-myocyte TP.

Functional level and its relationship to upper extremity function, pain, and muscle stiffness in children with Duchenne muscular dystrophy.

The progressive symptoms of Duchenne muscular dystrophy (DMD) negatively affect upper extremity skills, and this may have an effect that reduces the independence of daily life. The purpose of this study is to investigate the relationship between functional level and upper extremity function, pain, and stiffness in children with DMD. A total of 38 children with DMD were participated. The functional level of the upper and lower extremities was assessed using Brooke scale and Vignos scale. Upper extremity function, pain and stiffness were assessed using Upper Limb Short Questionnaire (ULSQ). The correlation between ULSQ and Brooke and Vignos scales was calculated. A moderate positive correlation was calculated between ULSQ total scores and Vignos scale (r = 0.52, p < 0.001) and Brooke scale (r = 0.65, p < 0.001). There was a moderate positive correlation between Vignos scale scores and ULSQ subscores of function (r = 0.42, p < 0.05) and stiffness (r = 0.56, p < 0.001); no significant correlation was found between pain scores and Vignos scale (p = 0.053). There was a moderate positive correlation between the function (r = 0.54, p < 0.001), pain (r = 0.40, p < 0.05), and stiffness (r = 0.62, p < 0.001) subscores of the ULSQ with the Brooke scale. In our study, there was a significant relationship between the functional level of patients with DMD and upper extremity function, pain, and muscle stiffness.

PCR105 The Impact of Key Health State Transitions on Health-Related Quality of Life (HRQOL) in Duchenne Muscular Dystrophy (DMD): A Qualitative Study

The progression of DMD is characterized by loss of ambulation (LOA) and upper limb function, cardiorespiratory impairment, and early mortality. While much attention is focused on LOA, the impact of other aspects of progression on HRQoL is less clear. Understanding patient perspectives on these aspects is important to provide context to clinical health states in DMD, and link changes in DMD symptoms to patient experiences. The objective of this study was to obtain insights on how key health state transitions affect HRQoL among individuals with DMD.

MiR-378 affects metabolic disturbances in the mdx model of Duchenne muscular dystrophy

Although Duchenne muscular dystrophy (DMD) primarily affects muscle tissues, the alterations to systemic metabolism manifested in DMD patients contribute to the severe phenotype of this fatal disorder. We propose that microRNA-378a (miR-378) alters carbohydrate and lipid metabolism in dystrophic mdx mice. In our study, we utilized double knockout animals which lacked both dystrophin and miR-378 (mdx/miR-378−/−). RNA sequencing of the liver identified 561 and 194 differentially expressed genes that distinguished mdx versus wild-type (WT) and mdx/miR-378−/− versus mdx counterparts, respectively. Bioinformatics analysis predicted, among others, carbohydrate metabolism disorder in dystrophic mice, as functionally proven by impaired glucose tolerance and insulin sensitivity. The lack of miR-378 in mdx animals mitigated those effects with a faster glucose clearance in a glucose tolerance test (GTT) and normalization of liver glycogen levels. The absence of miR-378 also restored the expression of genes regulating lipid homeostasis, such as Acly, Fasn, Gpam, Pnpla3, and Scd1. In conclusion, we report for the first time that miR-378 loss results in increased systemic metabolism of mdx mice. Together with our previous finding, demonstrating alleviation of the muscle-related symptoms of DMD, we propose that the inhibition of miR-378 may represent a new strategy to attenuate the multifaceted symptoms of DMD.

Dysregulated Autophagy and Mitophagy in a Mouse Model of Duchenne Muscular Dystrophy Remain Unchanged Following Heme Oxygenase-1 Knockout.

Dysregulation of autophagy may contribute to the progression of various muscle diseases, including Duchenne muscular dystrophy (DMD). Heme oxygenase-1 (HO-1, encoded by Hmox1), a heme-degrading enzyme, may alleviate symptoms of DMD, inter alia, through anti-inflammatory properties. In the present study, we determined the role of HO-1 in the regulation of autophagy and mitophagy in mdx animals, a commonly used mouse model of the disease. In the gastrocnemius of 6-week-old DMD mice, the mRNA level of mitophagy markers: Bnip3 and Pink1, as well as autophagy regulators, e.g., Becn1, Map1lc3b, Sqstm1, and Atg7, was decreased. In the dystrophic diaphragm, changes in the latter were less prominent. In older, 12-week-old dystrophic mice, diminished expressions of Pink1 and Sqstm1 with upregulation of Atg5, Atg7, and Lamp1 was depicted. Interestingly, we demonstrated higher protein levels of autophagy regulator, LC3, in dystrophic muscles. Although the lack of Hmox1 in mdx mice influenced blood cell count and the abundance of profibrotic proteins, no striking differences in mRNA and protein levels of autophagy and mitophagy markers were found. In conclusion, we demonstrated complex, tissue, and age-dependent dysregulation of mitophagic and autophagic markers in DMD mice, which are not affected by the additional lack of Hmox1.

Unravelling protein turnover in Duchenne muscular dystrophy: one protein at a time.

Unravelling protein turnover in Duchenne muscular dystrophy: one protein at a time.

Prediagnosis pathway benchmarking audit in patients with Duchenne muscular dystrophy

ObjectiveTo describe age and time at key stages in the Duchenne muscular dystrophy (DMD) prediagnosis pathway at selected centres to identify opportunities for service improvement.DesignA multicentre retrospective national audit.SettingNine tertiary...

Duchenne's muscular dystrophy involves a defective transsulfuration pathway activity

Duchenne muscular dystrophy (DMD) is the most frequent X chromosome-linked disease caused by mutations in the gene encoding for dystrophin, leading to progressive and unstoppable degeneration of skeletal muscle tissues. Despite recent advances in the understanding of the molecular processes involved in the pathogenesis of DMD, there is still no cure. In this study, we aim at investigating the potential involvement of the transsulfuration pathway (TSP), and its by-end product namely hydrogen sulfide (H2S), in primary human myoblasts isolated from DMD donors and skeletal muscles of dystrophic (mdx) mice. In myoblasts of DMD donors, we demonstrate that the expression of key genes regulating the H2S production and TSP activity, including cystathionine γ lyase (CSE), cystathionine beta-synthase (CBS), 3 mercaptopyruvate sulfurtransferase (3-MST), cysteine dioxygenase (CDO), cysteine sulfonic acid decarboxylase (CSAD), glutathione synthase (GS) and γ -glutamylcysteine synthetase (γ-GCS) is reduced. Starting from these findings, using Nuclear Magnetic Resonance (NMR) and quantitative Polymerase Chain Reaction (qPCR) we show that the levels of TSP-related metabolites such as methionine, glycine, glutathione, glutamate and taurine, as well as the expression levels of the aforementioned TSP related genes, are significantly reduced in skeletal muscles of mdx mice compared to healthy controls, at both an early (7 weeks) and overt (17 weeks) stage of the disease. Importantly, the treatment with sodium hydrosulfide (NaHS), a commonly used H2S donor, fully recovers the impaired locomotor activity in both 7 and 17 old mdx mice. This is an effect attributable to the reduced expression of pro-inflammatory markers and restoration of autophagy in skeletal muscle tissues. In conclusion, our study uncovers a defective TSP pathway activity in DMD and highlights the role of H2S-donors for novel and safe adjuvant therapy to treat symptoms of DMD.

Estrogen Deficiency Minimally Affects Diaphragm and Leg Muscle Functions in Female mdx Mice

Duchenne muscular dystrophy (DMD), an X-linked genetic disorder caused by mutations in the DMD gene, primarily affects 1 in 3,500 males. Despite DMD occurring predominantly in boys, female carriers, females who have a copy of the mutated DMD gene in one of two of their X chromosomes, may also display signs and symptoms of DMD. These women are termed manifesting carriers. Studies have shown that 2.5-17% of female carriers experience signs and symptoms of DMD. Similarly to DMD patients, manifesting carriers display skeletal muscle weakness and cardiomyopathy. Accumulating evidence from human and rodent studies show that estrogen deficiency, specifically, 17beta-estradiol (E2), contributes to further loss of skeletal muscle strength and reduced recovery after skeletal muscle injury. To date, there is a paucity of information on manifesting carriers pertaining to dystrophin-associated skeletal muscle weakness. Thus, we questioned whether female carriers who may not experience DMD symptoms early in life may develop clinical manifestations of DMD later in life due to the decline of estrogen. We hypothesized deficits of estrogen would compound skeletal muscle dysfunction in female mdx mice and decrease the ability of muscle to recover from eccentric contraction-induced injury. Ventilatory dysfunction was assessed using whole-body plethysmography and diaphragm muscle strength, fatigue, and recovery of strength were measured ex vivo. In vivo isometric torque, fatigue and recovery measurements, and eccentric contraction-induced injury and recovery measurements were assessed in the anterior crural muscles. No differences between sham and OVX mdx mice in ventilatory function, strength, or recovery of strength after fatigue in the diaphragm muscle or anterior crural muscles was detected (p ≥ 0.078). However, OVX mice had a blunted recovery of strength after injury compared to shammice (p ≤ 0.019). Although there was a minimal impact of estrogen deficiency on skeletal muscle contractile function in the diaphragm and leg muscles of female mdx mice, this study highlights the role of estrogen as a modulator of muscle recovery in female mdx mice after injury.

Urolithin A improves muscle function by inducing mitophagy in muscular dystrophy.

Duchenne muscular dystrophy (DMD) is the most common muscular dystrophy, and despite advances in genetic and pharmacological disease-modifying treatments, its management remains a major challenge. Mitochondrial dysfunction contributes to DMD, yet the mechanisms by which this occurs remain elusive. Our data in experimental models and patients with DMD show that reduced expression of genes involved in mitochondrial autophagy, or mitophagy, contributes to mitochondrial dysfunction. Mitophagy markers were reduced in skeletal muscle and in muscle stem cells (MuSCs) of a mouse model of DMD. Administration of the mitophagy activator urolithin A (UA) rescued mitophagy in DMD worms and mice and in primary myoblasts from patients with DMD, increased skeletal muscle respiratory capacity, and improved MuSCs' regenerative ability, resulting in the recovery of muscle function and increased survival in DMD mouse models. These data indicate that restoration of mitophagy alleviates symptoms of DMD and suggest that UA may have potential therapeutic applications for muscular dystrophies.

Impact of estrogen deficiency on diaphragm and leg muscle contractile function in female mdx mice.

Female carriers of Duchenne muscular dystrophy (DMD) presenting with DMD symptomology similar to males with DMD, such as skeletal muscle weakness and cardiomyopathy, are termed manifesting carriers. There is phenotypic variability among manifesting carriers including the age of onset, which can range from the first to fourth decade of life. In females, estrogen levels typically begin to decline during the fourth decade of life and estrogen deficiency contributes to loss of muscle strength and recovery of strength following injury. Thus, we questioned whether the decline of estrogen impacts the development of DMD symptoms in females. To address this question, we studied 6–8 month-old homozygous mdx female mice randomly assigned to a sham or ovariectomy (OVX) surgical group. In vivo whole-body plethysmography assessed ventilatory function and diaphragm muscle strength was measured in vitro before and after fatigue. Anterior crural muscles were analyzed in vivo for contractile function, fatigue, and in response to eccentric contraction (ECC)-induced injury. For the latter, 50 maximal ECCs were performed by the anterior crural muscles to induce injury. Body mass, uterine mass, hypoxia-hypercapnia ventilatory response, and fatigue index were analyzed by a pooled unpaired t-test. A two-way ANOVA was used to analyze ventilatory measurements. Fatigue and ECC-injury recovery experiments were analyzed by a two-way repeated-measures ANOVA. Results show no differences between sham and OVX mdx mice in ventilatory function, strength, or recovery of strength after fatigue in the diaphragm muscle or anterior crural muscles (p ≥ 0.078). However, OVX mice had significantly greater eccentric torque loss and blunted recovery of strength after ECC-induced injury compared to sham mice (p ≤ 0.019). Although the results show that loss of estrogen has minimal impact on skeletal muscle contractile function in female mdx mice, a key finding suggests that estrogen is important in muscle recovery in female mdx mice after injury.

Mitochondrial hydrogen sulfide supplementation improves health in the C. elegans Duchenne muscular dystrophy model

Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder characterized by progressive muscle degeneration and weakness due to mutations in the dystrophin gene. The symptoms of DMD share similarities with those of accelerated aging. Recently, hydrogen sulfide (H2S) supplementation has been suggested to modulate the effects of age-related decline in muscle function, and metabolic H2S deficiencies have been implicated in affecting muscle mass in conditions such as phenylketonuria. We therefore evaluated the use of sodium GYY4137 (NaGYY), a H2S-releasing molecule, as a possible approach for DMD treatment. Using the dys-1(eg33) Caenorhabditis elegans DMD model, we found that NaGYY treatment (100 µM) improved movement, strength, gait, and muscle mitochondrial structure, similar to the gold-standard therapeutic treatment, prednisone (370 µM). The health improvements of either treatment required the action of the kinase JNK-1, the transcription factor SKN-1, and the NAD-dependent deacetylase SIR-2.1. The transcription factor DAF-16 was required for the health benefits of NaGYY treatment, but not prednisone treatment. AP39 (100 pM), a mitochondria-targeted H2S compound, also improved movement and strength in the dys-1(eg33) model, further implying that these improvements are mitochondria-based. Additionally, we found a decline in total sulfide and H2S-producing enzymes in dystrophin/utrophin knockout mice. Overall, our results suggest that H2S deficit may contribute to DMD pathology, and rectifying/overcoming the deficit with H2S delivery compounds has potential as a therapeutic approach to DMD treatment.

Managing Chronic Health Needs in Child Care and Schools—Muscular Dystrophy

Patient Education| 2021 Managing Chronic Health Needs in Child Care and Schools—Muscular Dystrophy Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Share Icon Share Facebook Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Managing Chronic Health Needs in Child Care and Schools—Muscular Dystrophy. Pediatric Patient Education 2021; 10.1542/ppe_document126 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search nav search search input Search input auto suggest search filter All AAP SitesAll PublicationsPediatric Patient Education Search Advanced Search Subjects: Managing Chronic Health Needs in Child Care Muscular dystrophy is a group of genetic diseases that cause muscle wasting and weakness. The most common type is Duchenne muscular dystrophy, which is progressive and occurs only in boys. Duchenne muscular dystrophy occurs in 1 in 3,500 boys at birth. Females may be carriers. Myotonic dystrophy occurs at 1 in 8,000 of all births. Other types of muscular dystrophy are less common. The symptoms of Duchenne muscular dystrophy often start in the preschool age range, that is, 2 to 4 years of age. Symptoms might include being unable to get to standing from sitting and not being able to run. Children with this muscular dystrophy develop swayback, with their stomachs pushed forward, and walk on their toes. They can get leg and calf cramps and can appear clumsy. About a third of boys with Duchenne muscular dystrophy have intellectual disability;... © 2019 American Academy of Pediatrics. All rights reserved. You do not currently have access to this content.