Misdiagnosis is an important factor for diagnostic delay in McArdle disease

Diagnosis of McArdle disease is frequently delayed by many years following the first presentation of symptoms to a health professional. The aim of this study was to investigate the importance of misdiagnosis in delaying diagnosis of McArdle disease. The frequency of misdiagnosis, duration of diagnostic delay, categories of misdiagnoses and inappropriate medical interventions were assessed in 50 genetically confirmed patients. The results demonstrated a high frequency of misdiagnosis (90%, n = 45/50) most commonly during childhood years (67%; n = 30/45) compared with teenage years and adulthood (teenage: n = 7/45; adult n = 5/45; not known n = 3/45). The correct diagnosis of McArdle disease was rarely made before adulthood (median age of diagnosis 33 years). Thirty-one patients (62%) reported having received more than one misdiagnosis; the most common were “growing pains” (40%, n = 20) and “laziness/being unfit” (46%, n = 23). A psychiatric/psychological misdiagnosis was significantly more common in females than males (females 6/20; males 1/30; p < 0.01). Of the 45 patients who were misdiagnosed, 21 (47%) received incorrect management. This study shows that most patients with McArdle disease received an incorrect explanation of their symptoms providing evidence that misdiagnosis plays an important part in delaying implementation of appropriate medical advice and management to this group of patients.The authors would like to thank Mr Andrew Wakelin for his great and inspiring work. The authors would also like to thank AGSD-UK, CAPES Foundation, Muscular Dystrophy Campaign and the Euromac Registry for their support

Lasso, Meier, Powers. The Reality of the Modes under Scrutiny

Since Bernhard Meier’s publication of Die Tonarten der klassischen Vokalpolyphonie (1974), the role played by the modes in 16th-century music has been highly debated. Do they constitute an a priori compositional system comparable to harmonic tonality, as Meier believed? Are they an a posteriori classification system, as has been sustained by Harold Powers? This contribution attempts to answer these questions through the analysis of two cycles by Orlando di Lasso: the Psalmi Davidis poenitentiales (1584) and the Lagrime di San Pietro (1595). In order to assess Lasso’s vision of the modes, both cycles are subjected to a detailed analysis of tessituras and cadential turns. In this corpus, Lasso’s view of modes turns out to be shared by many contemporary theorists. Nevertheless, Lasso felt free enough to compose an a-modal work too. The motet Vide Homo, which finishes the Lagrime cycle, cannot be linked with any mode. It clearly shows how independent modes and counterpoint can be from each other. Counterpoint is self-sufficient and does not need modes. Through these analyses, I show that Meier and Powers both developed an incomplete and somehow one-sided view on 16th-century modes. Meier ascribed them a key role they did not necessarily fulfill, whereas Powers underestimated their possibly structural impact in compositional practice

Data from the European registry for patients with McArdle disease and other muscle glycogenoses (EUROMAC)

Background: The European registry for patients with McArdle disease and other muscle glycogenoses (EUROMAC) was launched to register rare muscle glycogenoses in Europe, to facilitate recruitment for research trials and to learn about the phenotypes and disseminate knowledge about the diseases through workshops and websites. A network of twenty full and collaborating partners from eight European countries and the US contributed data on rare muscle glycogenosis in the EUROMAC registry. After approximately 3 years of data collection, the data in the registry was analysed. Results: Of 282 patients with confirmed diagnoses of muscle glycogenosis, 269 had McArdle disease. New phenotypic features of McArdle disease were suggested, including a higher frequency (51.4%) of fixed weakness than reported before, normal CK values in a minority of patients (6.8%), ptosis in 8 patients, body mass index above background population and number of comorbidities with a higher frequency than in the background population (hypothyroidism, coronary heart disease). Conclusions: The EUROMAC project and registry have provided insight into new phenotypic features of McArdle disease and the variety of co-comorbidities affecting people with McArdle disease. This should lead to better management of these disorders in the future, including controlling weight, and preventive screening for thyroid and coronary artery diseases, as well as physical examination with attention on occurrence of ptosis and fixed muscle weakness. Normal serum creatine kinase in a minority of patients stresses the need to not discard a diagnosis of McArdle disease even though creatine kinase is normal and episodes of myoglobinuria are absent.Sin financiación4.123 JCR (2020) Q2, 64/175 Genetics & Heredity1.274 SJR (2020) Q1, 365/2448 Medicine (miscellaneous)No data IDR 2019UE

EUROMAC: A European registry for patients with McArdle disease and other very rare muscle glycogenoses

EUROMAC is a European registry of McArdle Disease patients and other very rare muscle glycogenosis (glycogenosis types 0, IV, VII, IX, X, XIII; phosphoglycerate kinase 1 deficiency and muscle lactate dehydrogenase deficiency) presenting with exercise intolerance as the key symptom. EUROMAC aims to promote awareness and understanding of McArdle disease and related conditions to harmonize standards of diagnosis and care and to promote research. EUROMAC was created and developed by a network of 15 partners from 7 EU countries, Turkey and US. Initially funded by the European Commission's Directorate General for Health and Consumers, the registry is currently supported by a grant received from the Fondo de Investigaciones Sanitarias (PI116/01492). Following informed consent from the participant, data (demographics, main clinical symptoms, comorbidities, age at diagnosis and genetic diagnosis) were uploaded onto a safe, encrypted web-based registry (https://www.registryeuromac.eu/en/). In parallel, education, training and dissemination activities were performed. EUROMAC is the largest international registry for patients with McArdle disease. As of March 2018, 313 patients from 10 different countries were recruited. The first Polish patient diagnosed with McArdle disease followed a EUROMAC teaching course, held in Warsaw. The implementation of the EUROMAC project and the setting-up of an international registry have significantly contributed to the effective dissemination of rare muscle GSDs, raising the awareness of these conditions. Additionally, it provided a unique insight into the co-comorbidities affecting people with McArdle disease that should lead to strategies to reduce and manage them in the future.Sin financiación3.115 JCR (2019) Q3, 76/204 Clinical Neurology1.177 SJR (2019) Q1, 85/378 Neurology (clinical)No data IDR 2019UE

Creation and implementation of a European registry for patients with McArdle disease and other muscle glycogenoses (EUROMAC registry)

Background International patient registries are of particular importance for rare disorders, as they may contribute to overcome the lack of knowledge derived from low number of patients and limited awareness of these diseases, and help to learn more about their geographical or population-based specificities, which is relevant for research purposes and for promoting better standards of care and diagnosis. Our objective was to create and implement a European registry for patients with McArdle disease and other muscle glycogenoses (EUROMAC) and to disseminate the knowledge of these disorders. Results Teams from nine different countries (United Kingdom, Spain, Italy, France, Germany, Denmark, Greece, Turkey and USA) created a consortium that developed the first European registry dedicated to rare muscle glycogenoses. A work plan was implemented to design the database and platform that constitute the registry, by choosing clinical, genetics and molecular variables of interest, based on experience gained from previous national registries for similar metabolic disorders. Among dissemination activities, several teaching events were organized in different countries, especially those where the consortium considered the awareness of these diseases needs to be promoted among health professionals and patients. Conclusion EUROMAC represents a step forward in the knowledge of those disorders to which it is dedicated, and will have relevant clinical outcomes at the diagnostic, epidemiological, clinical and research level.Spanish Instituto de Salud Carlos III, co-funded with European Regional Development Funds, ERDF (grants PI16/01492, PI19/01313 and CIBERER-ACCI 2016–03, to TP)4.123 JCR (2020) Q2, 64/175 Genetics & Heredity1.274 SJR (2020) Q1, 365/2448 Medicine (miscellaneous)No data IDR 2019UE