J. Kirschner

Loss of nephrocystin-3 function can cause embryonic lethality, Meckel-Gruber-like syndrome, situs inversus, and renal-hepatic-pancreatic dysplasia.

Many genetic diseases have been linked to the dysfunction of primary cilia, which occur nearly ubiquitously in the body and act as solitary cellular mechanosensory organelles. The list of clinical manifestations and affected tissues in cilia-related disorders (ciliopathies) such as nephronophthisis is broad and has been attributed to the wide expression pattern of ciliary proteins. However, little is known about the molecular mechanisms leading to this dramatic diversity of phenotypes. We recently reported hypomorphic NPHP3 mutations in children and young adults with isolated nephronophthisis and associated hepatic fibrosis or tapetoretinal degeneration. Here, we chose a combinatorial approach in mice and humans to define the phenotypic spectrum of NPHP3/Nphp3 mutations and the role of the nephrocystin-3 protein. We demonstrate that the pcy mutation generates a hypomorphic Nphp3 allele that is responsible for the cystic kidney disease phenotype, whereas complete loss of Nphp3 function results in situs inversus, congenital heart defects, and embryonic lethality in mice. In humans, we show that NPHP3 mutations can cause a broad clinical spectrum of early embryonic patterning defects comprising situs inversus, polydactyly, central nervous system malformations, structural heart defects, preauricular fistulas, and a wide range of congenital anomalies of the kidney and urinary tract (CAKUT). On the functional level, we show that nephrocystin-3 directly interacts with inversin and can inhibit like inversin canonical Wnt signaling, whereas nephrocystin-3 deficiency leads in Xenopus laevis to typical planar cell polarity defects, suggesting a role in the control of canonical and noncanonical (planar cell polarity) Wnt signaling.

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 risks of therapeutic misconception and individual patient (n=1) "trials" in rare diseases such as Duchenne dystrophy.

There is currently no cure for Duchenne muscular dystrophy, but there are some promising treatments in development, of which antisense-mediated exon skipping is close to clinical application. The results of the first trials have resulted in significant enthusiasm among clinicians, patients, and their parents and attracted widespread attention in both the scientific and lay press. As in many other rare diseases with significant morbidity this fuels the hope that at last an effective therapy might be within our reach. Parents, but also some clinicians, are now seriously considering treating individual patients with antisense oligonucleotides without waiting for proof from well-designed clinical trials that the new therapies are indeed effective and safe. We understand the sense of urgency that is experienced by patients, parents and their clinicians, but we hope to explain that the preliminary introduction of incompletely tested drugs might lead to dangerous and harmful situations for the patients, endanger the continuation of the development of possible effective therapeutic strategies, or even lead to a complete stop in the further development of promising drugs.There is currently no cure for Duchenne muscular dystrophy, but there are some promising treatments in development, of which antisense-mediated exon skipping is close to clinical application. The results of the first trials have resulted in significant enthusiasm among clinicians, patients, and their parents and attracted widespread attention in both the scientific and lay press. As in many other rare diseases with significant morbidity this fuels the hope that at last an effective therapy might be within our reach. Parents, but also some clinicians, are now seriously considering treating individual patients with antisense oligonucleotides without waiting for proof from well-designed clinical trials that the new therapies are indeed effective and safe. We understand the sense of urgency that is experienced by patients, parents and their clinicians, but we hope to explain that the preliminary introduction of incompletely tested drugs might lead to dangerous and harmful situations for the patients, endanger the continuation of the development of possible effective therapeutic strategies, or even lead to a complete stop in the further development of promising drugs.

Somatropin treatment of spinal muscular atrophy: A placebo-controlled, double-blind crossover pilot study

In preclinical studies growth hormone and its primary mediator IGF-1 have shown potential to increase muscle mass and strength. A single patient with spinal muscular atrophy reported benefit after compassionate use of growth hormone. Therefore we evaluated the efficacy and safety of growth hormone treatment for spinal muscular atrophy in a multicenter, randomised, double-blind, placebo-controlled, crossover pilot trial. Patients (n = 19) with type II/III spinal muscular atrophy were randomised to receive either somatropin (0.03 mg/kg/day) or placebo subcutaneously for 3 months, followed by a 2-month wash-out phase before 3 months of treatment with the contrary remedy. Changes in upper limb muscle strength (megascore for elbow flexion and hand-grip in Newton) were assessed by hand-held myometry as the primary measure of outcome. Secondary outcome measures included lower limb muscle strength, motor function using the Hammersmith Functional Motor Scale and other functional tests for motor function and pulmonary function. Somatropin treatment did not significantly affect upper limb muscle strength (point estimate mean: 0.08 N, 95% confidence interval (CI:-3.79;3.95, p = 0.965), lower limb muscle strength (point estimate mean: 2.23 N, CI:-2.19;6.63, p = 0.302) or muscle and pulmonary function. Side effects occurring during somatropin treatment corresponded with well-known side effects of growth hormone substitution in patients with growth hormone deficiency. In this pilot study, growth hormone treatment did not improve muscle strength or function in patients with spinal muscular atrophy type II/III.

Guidance in Social and Ethical Issues Related to Clinical, Diagnostic Care and Novel Therapies for Hereditary Neuromuscular Rare Diseases: "Translating" the Translational.

Drug trials in children engage with many ethical issues, from drug-related safety concerns to communication with patients and parents, and recruitment and informed consent procedures. This paper addresses the field of neuromuscular disorders where the possibility of genetic, mutation-specific treatments, has added new complexity. Not only must trial design address issues of equity of access, but researchers must also think through the implications of adopting a personalised medicine approach, which requires a precise molecular diagnosis, in addition to other implications of developing orphan drugs. It is against this background of change and complexity that the Project Ethics Council (PEC) was established within the TREAT-NMD EU Network of Excellence. The PEC is a high level advisory group that draws upon the expertise of its interdisciplinary membership which includes clinicians, lawyers, scientists, parents, representatives of patient organisations, social scientists and ethicists. In this paper we describe the establishment and terms of reference of the PEC, give an indication of the range and depth of its work and provide some analysis of the kinds of complex questions encountered. The paper describes how the PEC has responded to substantive ethical issues raised within the TREAT-NMD consortium and how it has provided a wider resource for any concerned parent, patient, or clinician to ask a question of ethical concern. Issues raised range from science related ethical issues, issues related to hereditary neuromuscular diseases and the new therapeutic approaches and questions concerning patients rights in the context of patient registries and bio-banks. We conclude by recommending the PEC as a model for similar research contexts in rare diseases.

Characterization of pulmonary function in 10–18 year old patients with Duchenne muscular dystrophy

Pulmonary function loss in patients with Duchenne muscular dystrophy (DMD) is progressive and leads to pulmonary insufficiency. The purpose of this study in 10-18 year old patients with DMD is the assessment of the inter-correlation between pulmonary function tests (PFTs), their reliability and the association with the general disease stage measured by the Brooke score. Dynamic PFTs (peak expiratory flow [PEF], forced vital capacity [FVC], forced expiratory volume in one second [FEV1]) and maximum static airway pressures (MIP, MEP) were prospectively collected from 64 DMD patients enrolled in the DELOS trial (ClinicalTrials.gov, number NCT01027884). Baseline PEF percent predicted (PEF%p) was <80% and patients had stopped taking glucocorticoids at least 12 months prior to study start. At baseline PEF%p, FVC%p and FEV1%p correlated well with each other (Spearmans rho: PEF%p-FVC%p: 0.54; PEF%p-FEV1%p: 0.72; FVC%p-FEV1%p: 0.91). MIP%p and MEP%p correlated well with one another (MIP%p-MEP%p: 0.71) but less well with PEF%p (MIP%p-PEF%p: 0.40; MEP%p-PEF%p: 0.41) and slightly better with FVC%p (MIP%p-FVC%p: 0.59; MEP%p-FVC%p: 0.74). The within-subject coefficients of variation (CV) for successive measures were 6.97% for PEF%p, 6.69% for FVC%p and 11.11% for FEV1%p, indicating that these parameters could be more reliably assessed compared to maximum static airway pressures (CV for MIP%p: 18.00%; MEP%p: 15.73%). Yearly rates of PFT decline (placebo group) were larger in dynamic parameters (PEF%p: -8.9% [SD 2.0]; FVC%p: -8.7% [SD 1.1]; FEV1%p: -10.2% [SD 2.0]) than static airway pressures (MIP%p: -4.5 [SD 1.3]; MEP%p: -2.8 [SD 1.1]). A considerable drop in dynamic pulmonary function parameters was associated with loss of upper limb function (transition from Brooke score category 4 to category 5). In conclusion, these findings expand the understanding of the reliability, correlation and evolution of different pulmonary function measures in DMD patients who are in the pulmonary function decline phase.

Early and lethal neurodegeneration with myasthenic and myopathic features: A new ALG14-CDG

Objective: To describe the presentation and identify the cause of a new clinical phenotype, characterized by early severe neurodegeneration with myopathic and myasthenic features. Methods: This case study of 5 patients from 3 families includes clinical phenotype, serial MRI, electrophysiologic testing, muscle biopsy, and full autopsy. Genetic workup included whole exome sequencing and segregation analysis of the likely causal mutation. Results: All 5 patients showed severe muscular hypotonia, progressive cerebral atrophy, and therapy-refractory epilepsy. Three patients had congenital contractures. All patients died during their first year of life. In 2 of our patients, electrophysiologic testing showed abnormal decrement, but treatment with pyridostigmine led only to temporary improvement. Causative mutations in ALG14 were identified in all patients. The mutation c.220 G>A (p.Asp74Asn) was homozygous in 2 patients and heterozygous in the other 3 patients. Additional heterozygous mutations were c.422T>G (p.Val141Gly) and c.326G>A (p.Arg109Gln). In all cases, parents were found to be heterozygous carriers. None of the identified variants has been described previously. Conclusions: We report a genetic syndrome combining myasthenic features and severe neurodegeneration with therapy-refractory epilepsy. The underlying cause is a glycosylation defect due to mutations in ALG14. These cases broaden the phenotypic spectrum associated with ALG14 congenital disorders of glycosylation as previously only isolated myasthenia has been described.

How reference networks develop, implement, and monitor guidelines

Rare diseases pose many challenges. A paucity of randomised controlled trials for most conditions means that best-practice care guidelines are often non-existent or poorly developed. Where they exist, healthcare professionals may be unaware of them. Furthermore, evaluation of guidelines is difficult, as traditional methods of health-care research (such as hospital admissions and mortality statistics with ICD codes) are not applicable to rare diseases. The CARE-NMD project to improve care for Duchenne muscular dystrophy (DMD) provides an example of how Reference Networks may develop, implement and monitor rare disease guidelines. The development of the DMD care guidelines was facilitated by the US Centres for Disease Control, and led by patient organisations, translational research networks, and health agencies. In the absence of overwhelming clinical trial evidence, 84 international experts used the RAND/UCLA Appropriateness Method (RAM) to generate consensus on the necessity and appropriateness of clinical interventions and assessments. Yet despite the guidelines, many DMD patients do not receive the treatment they describe. CARE-NMD has established a Reference Network of care centres for DMD in Europe, to disseminate guidelines, evaluate current practice and identify reasons for non-compliance, and assess guideline impact on quality of life. Dissemination, via professional and patient networks, has addressed the problem of a lack of awareness of guidelines for this rare disease. Strategies have included presentations at meetings, journal and website publications, media interviews, and professional training courses tailored to local needs in East European partner countries. The ‘Family Guide’, a more accessible version of the care guidelines, is now available in over 20 languages and has been very well received. To monitor implementation, the project has conducted the largest ever cross-sectional study of DMD patients and their families (n=1677, response rate 66%) across 7 European countries. This assessed – via process and outcome indicators – whether the care they receive aligns with the consensus guidelines, and reported quality of life. In addition, a survey of healthcare professionals has been distributed to care sites in these countries via the Care and Trial Site Registry (CTSR), an online self-registration platform for neuromuscular centres developed by the TREAT-NMD network of excellence. This now includes information on patient cohort, care settings, research activities and clinical trial capabilities of more than 200 sites. A Reference Network such as CARE-NMD enables implementation, assessment and monitoring of care guidelines for rare diseases. The data it gathers will be crucial in further developing and refining guidelines.

G.P.272

Tropomyosin 3 encoded by the TPM3 gene is a member of the acting binding tropomyosin family, a component of the sarcomeric thin filaments troponin tropomyosin complex that is essential in muscle contraction by regulating the calcium dependent binding of the myosin head to the actin filament in anticipation of the force generating power stroke. Mutations in TPM3 cause a clinical and histopathological heterogeneous group of neuromuscular disorders characterized by progressive weakness that includes CAP myopathy, congenital fiber type disproportion and nemaline myopathy. Recent studies of the deltaK7 mutation in TPM2 suggest that the pathogenic mechanism underlying tropomyosin related disease with progressive muscle contractures may be a gain of function change, leading to elevated Ca 2+ sensitivity of force generation, while this has not yet been shown conclusively for TPM3 . Here we report two unrelated patients with a de novo TPM3 single glutamic acid deletions resulting in a much more significant contractile phenotype with marked congenital muscle stiffness associated with ventilator failure in one case. We hypothesize that these single amino acid deletions result in increased Ca 2+ sensitivity of the troponin tropomyosin complex and a consequently hypercontractile sarcomere. We thus expand the clinical, phenotypic and pathophysiological spectrum of TPM3 mutations, which now join recessive α B-crystallin mutations and specific ACTA1 and TPM2 mutations as a myogenic cause for neonatal muscle rigidity.

S.P.59 Current care practice in Duchenne Muscular Dystrophy in Europe – results of the CARE-NMD cross-sectional survey

Abstract CARE-NMD is an EU-funded project to improve care for patients with Durchenne Muscular Dystrophy (DMD). The analysis of the current care practice is the first step to identify gaps and to plan specific measures such as training sessions for professionals and workshops for patients. For this purpose, a large cross-sectional patient-survey about the received care and quality of life of patients with DMD has been performed since September 2011 in seven European countries: Bulgaria, Czech Republic, Denmark, Germany, Hungary, Poland and the United Kingdom. A total of 1,677 patients with Duchenne Muscular Dystrophy have received questionnaires via the national patient registries. For the assessment of quality of care we defined outcome and process indicators. Outcome indicators include stage of the disease, age at loss of ambulation, ability to sit, number of hospitalisations, cardiac and pulmonary function and age at diagnosis. Process indicators comprise the frequency of medical assessments and received treatment, e.g. the use of corticosteroids, non-invasive ventilation and assistive devices. By March 31st 1,093 of 1,677 patients/families responded (66 percent). Response by country were: Bulgaria 45/73, Czech Republic 92/191, Denmark 92/131, Germany 440/545, Hungary 62/70, Poland 137/246, and for United Kingdom 223/421. Key findings about health status, received treatment, and quality of life of patients with DMD in Europe will be presented. This is the largest ever cross-sectional survey of the care and quality of life of people with DMD. The final results will provide detailed insight into the current situation of people with DMD in Europe and help to identify gaps to further improve the situation of affected patients and families.