The TREAT-NMD DMD Global Database: analysis of more than 7,000 Duchenne muscular dystrophy mutations.

Analyzing the type and frequency of patient-specific mutations that give rise to Duchenne muscular dystrophy (DMD) is an invaluable tool for diagnostics, basic scientific research, trial planning, and improved clinical care. Locus-specific databases allow for the collection, organization, storage, and analysis of genetic variants of disease. Here, we describe the development and analysis of the TREAT-NMD DMD Global database (http://umd.be/TREAT_DMD/). We analyzed genetic data for 7,149 DMD mutations held within the database. A total of 5,682 large mutations were observed (80% of total mutations), of which 4,894 (86%) were deletions (1 exon or larger) and 784 (14%) were duplications (1 exon or larger). There were 1,445 small mutations (smaller than 1 exon, 20% of all mutations), of which 358 (25%) were small deletions and 132 (9%) small insertions and 199 (14%) affected the splice sites. Point mutations totalled 756 (52% of small mutations) with 726 (50%) nonsense mutations and 30 (2%) missense mutations. Finally, 22 (0.3%) mid-intronic mutations were observed. In addition, mutations were identified within the database that would potentially benefit from novel genetic therapies for DMD including stop codon read-through therapies (10% of total mutations) and exon skipping therapy (80% of deletions and 55% of total mutations)

Are Peripheral Blood Mononuclear Cells Derived from Patients with Certain Myopathies Suitable for Personalized Drug Screening?

Background: Limb girdle muscular dystrophies (LGMDs) and several other disorders which share their specific phenotype are rare, predominantly hereditary conditions with no curative treatment. Differential diagnosis of these myopathies is quite challenging and expensive in many cases. Therefore, a significant proportion of patients remains undiagnosed and untreated for a long time. At the same time there is a huge amount of drugs and supplements potentially able to modify the course of some of these muscular dystrophies. That is why a simple empirical approach able to define a patient’s reaction to a specific compound seems rational. Because most common basic pathogenetic mechanisms for these quite different disorders increase the vulnerability of muscle cells (or decrease ability for reparation) during mechanical stress, we propose a simple, noninvasive and inexpensive approach for individualized drug screening based on the drug’s influence on the mechanical vulnerability of peripheral blood mononuclear cells (PBMC). Methods: PBMC derived from 8 patients with Duchenne muscular dystrophy (DMD), 2 patients with LGMD2A, 1 patient with LGMD2B, 1 with MERRF syndrome, 1 with facioscapulohumeral muscular dystrophy (FSHD) and 13 matched control subjects were irradiated by ultrasound in the presence of several compounds (lisinopril, vitamin D3, prednisolon, tocopherol, topiramate, glutargin, α-lipoic acid, essentiale, and physiological solution). Then viability indexes of the samples were detected by citotoxic assays based on vital dye (neutral red and resazurin) metabolism. Results: In cytotoxicity tests with active transport of neutral red into PBMC derived from DMD patients, the cells showed signs of destruction at 1.06±0.52 minutes of ultrasounding compared to 1.75±0.6 minutes in control. PBMCs from patients with other myopathies have either normal or decreased resistance to ultrasound. The addition of tocopherol significantly changes the PBMC time-destruction curves; however, these changes as well as changes caused by other compounds were inconclusive concerning their protective effects. In resazurin cytotoxicity tests, PBMC metabolic activity normalized to 0.9% NaCl in the presence of tested compounds differed significantly in experiments with and without ultrasounding. Also, profiles of the compounds’ protective effects were very dissimilar in patients with different myopathies. Conclusion: We believe that peculiarities of PBCM behavior after US stress in the presence of different compounds are reliable patient-specific phenomena, which warrant further investigation and a proposed approach worth further improvement

The TREAT-NMD Duchenne Muscular Dystrophy Registries: Conception, Design, and Utilization by Industry and Academia.

Duchenne muscular dystrophy (DMD) is an X-linked genetic disease, caused by the absence of the dystrophin protein. Although many novel therapies are under development for DMD, there is currently no cure and affected individuals are often confined to a wheelchair by their teens and die in their twenties/thirties. DMD is a rare disease (prevalence <5/10,000). Even the largest countries do not have enough affected patients to rigorously assess novel therapies, unravel genetic complexities, and determine patient outcomes. TREAT-NMD is a worldwide network for neuromuscular diseases that provides an infrastructure to support the delivery of promising new therapies for patients. The harmonized implementation of national and ultimately global patient registries has been central to the success of TREAT-NMD. For the DMD registries within TREAT-NMD, individual countries have chosen to collect patient information in the form of standardized patient registries to increase the overall patient population on which clinical outcomes and new technologies can be assessed. The registries comprise more than 13,500 patients from 31 different countries. Here, we describe how the TREAT-NMD national patient registries for DMD were established. We look at their continued growth and assess how successful they have been at fostering collaboration between academia, patient organizations, and industry

The TREAT-NMD DMD Global Database: analysis of more than 7,000 Duchenne muscular dystrophy mutations

Analyzing the type and frequency of patient-specific mutations that give rise to Duchenne muscular dystrophy (DMD) is an invaluable tool for diagnostics, basic scientific research, trial planning, and improved clinical care. Locus-specific databases allow for the collection, organization, storage, and analysis of genetic variants of disease. Here, we describe the development and analysis of the TREAT-NMD DMD Global database (http://umd.be/TREAT_DMD/). We analyzed genetic data for 7,149 DMD mutations held within the database. A total of 5,682 large mutations were observed (80% of total mutations), of which 4,894 (86%) were deletions (1 exon or larger) and 784 (14%) were duplications (1 exon or larger). There were 1,445 small mutations (smaller than 1 exon, 20% of all mutations), of which 358 (25%) were small deletions and 132 (9%) small insertions and 199 (14%) affected the splice sites. Point mutations totalled 756 (52% of small mutations) with 726 (50%) nonsense mutations and 30 (2%) missense mutations. Finally, 22 (0.3%) mid-intronic mutations were observed. In addition, mutations were identified within the database that would potentially benefit from novel genetic therapies for DMD including stop codon read-through therapies (10% of total mutations) and exon skipping therapy (80% of deletions and 55% of total mutations).Contract grant sponsor(s): TREAT-NMD (FP6LSHM-CT-2006-036825, 20123307 UNEW_FY2013, and AFM 16104); European Union Seventh Framework Programme (FP7/2007-2013) (305444 [RD-Connect] and 305121 [Neuromics]).S

Clinical Outcomes in Duchenne Muscular Dystrophy: A Study of 5345 Patients from the TREAT-NMD DMD Global Database

Background: Recent short-term clinical trials in patients with Duchenne Muscular Dystrophy (DMD) have indicated greater disease variability in terms of progression than expected. In addition, as average life-expectancy increases, reliable data is required on clinical progression in the older DMD population. Objective: To determine the effects of corticosteroids on major clinical outcomes of DMD in a large multinational cohort of genetically confirmed DMD patients. Methods: In this cross-sectional study we analysed clinical data from 5345 genetically confirmed DMD patients from 31 countries held within the TREAT-NMD global DMD database. For analysis patients were categorised by corticosteroid background and further stratified by age. Results: Loss of ambulation in non-steroid treated patients was 10 years and in corticosteroid treated patients 13 years old (p = 0.0001). Corticosteroid treated patients were less likely to need scoliosis surgery (p < 0.001) or ventilatory support (p < 0.001) and there was a mild cardioprotective effect of corticosteroids in the patient population aged 20 years and older (p = 0.0035). Patients with a single deletion of exon 45 showed an increased survival in contrast to other single exon deletions. Conclusions: This study provides data on clinical outcomes of DMD across many healthcare settings and including a sizeable cohort of older patients. Our data confirm the benefits of corticosteroid treatment on ambulation, need for scoliosis surgery, ventilation and, to a lesser extent, cardiomyopathy. This study underlines the importance of data collection via patient registries and the critical role of multi-centre collaboration in the rare disease field.This work was supported by TREAT-NMD operating grants, FP6 LSHM-CT-2006-036825, 20123307 UNEW FY2013 and AFM 16104. Further support came from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 305444 (RD-Connect) and 305121 (Neuromics) and Medical Research Council UK (reference G1002274, grant ID 98482).S