Current management of Duchenne muscular dystrophy in the Middle East: expert report

Clinical practice guidelines for the diagnosis and management of Duchenne muscular dystrophy: a scoping review

Introduction

Our objective was to identify recent CPGs for the diagnosis and management of DMD and summarize their characteristics and reliability.

Methods

We conducted a scoping review of CPGs using MEDLINE, the Turning Research Into Practice (TRIP) database, Google Scholar, guidelines created by organizations, and other repositories to identify CPGs published in the last 5 years. Our protocol was drafted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses for scoping reviews. To assess the reliability of the CPGs, we used all the domains included in the Appraisal of Guidelines Research and Evaluation II.

Results

We selected three CPGs published or updated between 2015 and 2020. All the guidelines showed good or adequate methodological rigor but presented pitfalls in stakeholder involvement and applicability domains. Recommendations were coherent across CPGs on steroid treatment, except for minor differences in dosing regimens. However, the recommendations were different for new drugs.

Discussion

There is a need for current and reliable CPGs that develop broad topics on the management of DMD and consider the challenges of developing recommendations for RDs.

The challenges faced by patients with hereditary myopathy during the COVID-19 pandemic

BACKGROUND

Neuromuscular diseases are inherited and the prevalance of neuromuscular disease is estimated to be around 1:2000.

METHODS

This cross-sectional research was conducted with a qualitative research model. Data were collected from patients with an online survey using the snowball sampling method. The study was conducted in accordance with the STROBE checklist methodology. Frequencies and percentages were used to analyse demographic data, and content analysis was used for qualitative opinions.

RESULTS

Most of the participants were men and their education levels were low. Participants reported experiencing physical and socio-economic barriers to accessing healthcare. Participants also stated that these barriers have worsened since COVID-19.

CONCLUSIONS

Patients with hereditary myopathy are stigmatised by society and face different problems depending on the type of disease and level of function. It is recommended that decision-makers enable patients with hereditary myopathy in exceptional situations to access healthcare services and take steps to resolve their problems.

Duchenne Muscular Dystrophy from Brain to Muscle: The Role of Brain Dystrophin Isoforms in Motor Functions

Brain function and its effect on motor performance in Duchenne muscular dystrophy (DMD) is an emerging concept. The present study explored how cumulative dystrophin isoform loss, age, and a corticosteroid treatment affect DMD motor outcomes. A total of 133 genetically confirmed DMD patients from Sri Lanka were divided into two groups based on whether their shorter dystrophin isoforms (Dp140, Dp116, and Dp71) were affected: Group 1, containing patients with Dp140, Dp116, and Dp71 affected (n = 98), and Group 2, containing unaffected patients (n = 35). A subset of 52 patients (Group 1, n = 38; Group 2, n = 14) was followed for up to three follow-ups performed in an average of 28-month intervals. The effect of the cumulative loss of shorter dystrophin isoforms on the natural history of DMD was analyzed. A total of 74/133 (56%) patients encountered developmental delays, with 66/74 (89%) being in Group 1 and 8/74 (11%) being in Group 2 (p < 0.001). Motor developmental delays were predominant. The hip and knee muscular strength, according to the Medical Research Council (MRC) scale and the North Star Ambulatory Assessment (NSAA) activities, "standing on one leg R", "standing on one leg L", and "walk", declined rapidly in Group 1 (p < 0.001 In the follow-up analysis, Group 1 patients became wheelchair-bound at a younger age than those of Group 2 (p = 0.004). DMD motor dysfunction is linked to DMD mutations that affect shorter dystrophin isoforms. When stratifying individuals for clinical trials, considering the DMD mutation site and its impact on a shorter dystrophin isoform is crucial.

Instrumented strength assessment in typically developing children and children with a neural or neuromuscular disorder: A reliability, validity and responsiveness study

The aim of this study was to determine the clinimetric properties, i.e., reliability, validity and responsiveness of an instrumented strength assessment in typically developing (TD) children and children with cerebral palsy (CP) and Duchenne muscular dystrophy (DMD). Force (N), torque (Nm) and normalized torque (Nm/kg) were defined for maximal voluntary isometric contractions (MVICs) of the lower limb muscles using a pre-established protocol. Intraclass correlation coefficient (ICC), standard error of measurement (SEM) and minimal detectable change (MDC) of TD children (n = 14), children with CP (n = 11) and DMD (n = 11) were used to evaluate intra-rater reliability for the three cohorts and the inter-rater intersession as well as inter-rater intrasession reliability for TD children. Construct validity was assessed by comparing MVICs in TD children (n = 28) to children with CP (n = 26) and to children with DMD (n = 30), using the Kruskal Wallis and post-hoc Mann-Whitney U tests. Responsiveness was investigated by assessing changes in MVICs following a strength intervention in CP (n = 26) and a 1 and 2 year follow-up study in DMD (n = 13 and n = 6, respectively), using the Wilcoxon Signed-Rank test. The overall intra-rater reliability, was classified as good to excellent for 65.1%, moderate for 27.0% and poor for 7.9% of the measures (47.6%, 76.2%, and 66.7% good-excellent; 28.6%, 23.8%, and 33.7% moderate; 23.8%, 0%, and 0% poor in TD, CP, and DMD, respectively), while ICC values for TD children were slightly lower for inter-rater intrasession reliability (38.1% good-excellent, 33.3% moderate and 26.6% poor) and for inter-rater intersession reliability (47.6% good-excellent, 23.8% moderate and 28.6% poor). Children with CP and DMD were significantly weaker than TD children (p < 0.001) and the majority of these strength differences exceeded the MDC. Children with CP significantly improved strength after training, with changes that exceeded the SEMs, whereas only limited strength decreases over time were observed in the DMD cohort. In conclusion, the investigated instrumented strength assessment was sufficiently reliable to confirm known-group validity for both cohorts and could detect the responsiveness of children with CP after a strength intervention. However, more research is necessary to determine the responsiveness of this assessment in children with DMD regarding their natural decline.

Gene Therapy for Duchenne Muscular Dystrophy: Unlocking the Opportunities in Countries in the Middle East and Beyond

Background: Duchenne muscular dystrophy (DMD) is a severe neuromuscular disorder which leads to progressive muscle degeneration and weakness. Most patients die from cardiac or respiratory failure. Gene transfer therapy offers a promising approach to treating this disorder. Objective: Given the genetic disease burden, family size, and the high consanguinity rates in the Middle East, our objective is to address current practices and challenges of DMD patient care within two countries in this region, namely the United Arab Emirates and Kuwait, and to outline readiness for gene therapy. Methods: An expert panel meeting was held to discuss the DMD patient journey, disease awareness, current management of DMD, challenges faced and recommendations for improvement. Opportunities and challenges for gene therapy in both countries were also deliberated. A pre-meeting survey was conducted, and the results were used to guide the discussion during the meeting. Results: DMD awareness is poor resulting in a delay in referral and diagnosis of patients. Awareness and education initiatives, along with an interconnected referral system could improve early diagnosis. Genetic testing is available in both countries although coverage varies. Corticosteroid therapy is the standard of care however there is often a delay in treatment initiation. Patients with DMD should be diagnosed and managed by a multi-disciplinary team in centers of excellence for neuromuscular disorders. Key success factors to support the introduction of gene therapy include education and training, timely and accessible genetic testing and resolution of reimbursement and cost issues. Conclusion: There are many challenges facing the management of DMD patients in the United Arab Emirates and Kuwait and most likely other countries within the Middle East. Successful introduction of gene therapy to treat DMD will require careful planning, education, capacity building and prioritization of core initiatives.

Development and economic evaluation of a patient-centered care model for children with Duchenne’s Muscular Dystrophy: A quasi-experimental study protocol (Preprint)

BACKGROUND

Duchenne muscular dystrophy (DMD) is a rare progressive muscular disease that primarily affects boys. A lack of comprehensive care for patients living with DMD is directly associated with a compromised quality of life (QoL) for those affected and their caregivers. This disease also has a huge economic impact on families as its treatment requires substantial direct, indirect, and informal care costs.

OBJECTIVE

This study presents a protocol developed to evaluate the feasibility and efficacy of a patient-centered care (PCC) model for children with DMD. The care model was designed with the aim to empower families, improve QoL, and reduce economic burden on their families.

METHODS

This study is planned as a quasi-experimental study that will enroll 70 consecutive families with boys (aged 5-15 years) with DMD visiting a tertiary care center. The study is being conducted in 2 phases (preintervention and postintervention phases, referred to as phase 1 and phase 2, respectively). During phase 1, the patients received routine care. The study is now in phase 2, with the intervention currently being administered. The intervention is based on the PCC model individualized by the intervention team. The model has a comprehensive DMD telecare component that includes teleconsultation as one of its key components to reduce in-person physician visits at the health facility. Teleconsultation is especially beneficial for late-ambulatory and nonambulatory patients. Data on economic burden are being collected for out-of-pocket expenses for both phases during in-person visits via telephone or messaging apps on a monthly basis. QoL data for patients and their primary caregivers are being collected at 3 time points (ie, time of enrollment, end of phase 1, and end of phase 2). Outcome measures are being assessed as changes in economic burden on families and changes in QoL scores.

RESULTS

Participant recruitment began in July 2021. The study is ongoing and expected to be completed by March 2023. The findings based on baseline data are expected to be submitted for publication in 2023.

CONCLUSIONS

This paper outlines a research proposal developed to study the impact of a PCC model for patients with DMD in low- and middle-income countries (LMICs). This study is expected to provide evidence of whether a multicomponent, patient-centric intervention could reduce economic burdens on families and improve their QoL. The results of this study could guide policy makers and health professionals in India and other LMICs to facilitate a comprehensive care program for patients living with DMD. The economic impact of a rare disease is an important consideration to formulate or evaluate any health policy or intervention related to new treatments and financial support schemes.

TRIAL REGISTRATION

Clinical Trials Registry India (ICMR-NIMS) CTRI/2021/06/034274; https://www.ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=56650.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/42491.

Patient demographics and characteristics from an ambispective, observational study of patients with duchenne muscular dystrophy in Saudi Arabia

Duchenne muscular dystrophy (DMD) is a rare neuromuscular disorder that is characterized by progressive muscle weakness, resulting in disability and premature death. Onset of symptoms typically occurs at 2-3 years of age, and disease progression is managed through treatment with corticosteroids. The aim of this interim analysis is to increase disease awareness and improve patient management in Saudi Arabia (SA) through the use of data from an ongoing ambispective, observational, multicenter study evaluating characteristics of patients aged 1-14 years with genetically confirmed DMD in SA. This interim analysis examined the secondary outcomes from the study-the demographics and clinical characteristics of patients included retrospectively [data recorded (enrollment visit) between January 2014 and September 2020] and prospectively between September 2020 and April 2021. The primary outcome-the list of DMD gene mutations for the study population-will be reported at a later date. There were 177 eligible patients. Mean, standard deviation (SD) age at enrollment was 7.5 (3.0) years. Median (min, max) age at diagnosis was 7.0 (1.3, 13.8) years. At enrollment, 28.9% of patients were full-time wheelchair users, 50.0% of ambulatory patients could run, and 63.9% could climb stairs. The mean (SD) ages of patients at enrollment who were unable to run and climb stairs were 8.0 (2.7) and 7.6 (3.0) years, respectively. Speech delay (19.4%) and learning difficulties (14.9%) were the most commonly reported intellectual impairments. Physical therapy (84.2%) was the most common choice for initial management of DMD. Only 40.7% of patients received corticosteroid therapy as part of their initial management plan, rising to 59.1% at enrollment. Devices were given to 28.8% of patients for initial management, most commonly ankle-foot orthoses (26.0%) and wheelchairs (6.2%). This analysis reports data from the largest study to date to capture demographics and clinical characteristics of DMD patients in SA. The interim results show a relatively late DMD diagnosis age compared with that in other countries, and a need for improved adherence to international DMD standard of care guidelines. Therefore, there is an urgent requirement for improved DMD education and awareness among healthcare professionals and the public in SA.

A 20-year Clinical and Genetic Neuromuscular Cohort Analysis in Lebanon: An International Effort

BACKGROUND

Clinical and molecular data on the occurrence and frequency of inherited neuromuscular disorders (NMD) in the Lebanese population is scarce.

OBJECTIVE

This study aims to provide a retrospective overview of hereditary NMDs based on our clinical consultations in Lebanon.

METHODS

Clinical and molecular data of patients referred to a multi-disciplinary consultation for neuromuscular disorders over a 20-year period (1999-2019) was reviewed.

RESULTS

A total of 506 patients were diagnosed with 62 different disorders encompassing 10 classes of NMDs. 103 variants in 49 genes were identified. In this cohort, 81.4%of patients were diagnosed with motor neuron diseases and muscular dystrophies, with almost half of these described with spinal muscular atrophy (SMA) (40.3%of patients). We estimate a high SMA incidence of 1 in 7,500 births in Lebanon. Duchenne and Becker muscular dystrophy were the second most frequently diagnosed NMDs (17%of patients). The latter disorders were associated with the highest number of variants (39) identified in this study. A highly heterogeneous presentation of Limb Girdle Muscular Dystrophy and Charcot-Marie-Tooth disease was notably identified. The least common disorders (5.5%of patients) involved congenital, metabolic, and mitochondrial myopathies, congenital myasthenic syndromes, and myotonic dystrophies. A review of the literature for selected NMDs in Lebanon is provided.

CONCLUSIONS

Our study indicates a high prevalence and underreporting of heterogeneous forms of NMDs in Lebanon- a major challenge with many novel NMD treatments in the pipeline. This report calls for a regional NMD patient registry.

Case Report: The Genetic Diagnosis of Duchenne Muscular Dystrophy in the Middle East

The timely and accurate genetic diagnosis of Duchenne muscular dystrophy (DMD) enables prompt initiation of disease management and genetic counseling and optimal patient care. Despite the existence of best practice guidelines for the diagnosis of DMD, implementation of these recommendations in different parts of the world is challenging. Here, we present 4 unique case studies which illustrate the different diagnostic pathways of patients with DMD in Middle Eastern countries and highlight region-specific challenges to achieving timely and accurate genetic diagnosis of DMD. A lack of disease awareness and consequential failure to recognize the signs and symptoms of DMD significantly contributed to the delayed diagnoses of these patients. Additional challenges included limited available funding for genetic testing and a lack of local specialist and genetic testing centers, causing patients and their families to travel vast distances for appointments in some countries. Earlier and more accurate genetic diagnosis of DMD in this region would allow patients to benefit from effective disease management, leading to improvements in health-related quality of life.

DMD-related muscular dystrophy in Cameroon: Clinical and genetic profiles

BACKGROUND

Most of the previous studies on Duchenne Muscular Dystrophy (DMD) were conducted in Caucasian, Asian, and Arab populations. Therefore, little is known about the features of this disease in Africans. In this study, we aimed to determine the clinical characteristics of DMD, and the common mutations associated with this condition in a group of Cameroonian patients.

METHODS

We recruited DMD patients and performed a general physical examination on each of them. Multiplex ligand-dependant probe amplification was carried out to investigate exon deletions and duplications in the DMD gene (OMIM: 300377) of patients and their mothers.

RESULTS

A total of 17 male patients from 14 families were recruited, aged 14 ± 5.1 (8-23) years. The mean age at onset of symptoms was 4.6 ± 1.5 years, and the mean age at diagnosis was 12.1 ± 5.2 years. Proximal muscle weakness was noted in all patients and calf hypertrophy in the large majority of them (88.2%; 15/17). Flexion contractures were particularly frequent on the ankle (85.7%; 12/14). Wasting of shoulder girdle and thigh muscles was present in 50% (6/12) and 46.2% (6/13) of patients, respectively. No patient presented with hearing impairment. Deletions in DMD gene (OMIM: 300377) occurred in 45.5% of patients (5/11), while duplications were observed in 27.3% (3/11). Both mutation types were clustered between exons 45 and 50, and the proportion of de novo mutation was estimated at 18.2% (2/11).

CONCLUSION

Despite the first symptoms of DMD occurring in infancy, the diagnosis is frequently made later in adolescence, indicating an underestimation of the number of cases of DMD in Cameroon. Future screening of deletions and duplications in patients from Cameroon should focus on the distal part of the gene.