Data from the European registry for patients with McArdle disease (EUROMAC): functional status and social participation.

BACKGROUND: The European registry for individuals with GSD5 and other muscle glycogenosis (EUROMAC) was launched to register rare muscle glycogenosis in Europe, to facilitate recruitment for research trials and to learn about the phenotypes and disseminate knowledge about the diseases. A network of twenty collaborating partners from eight European countries and the US contributed data on rare muscle glycogenosis in the EUROMAC registry. METHODS: Following the initial report on demographics, neuromuscular features and comorbidity (2020), we here present the data on social participation, previous and current treatments (medication, supplements, diet and rehabilitation) and limitations. Furthermore, the following questionnaires were used: Fatigue severity scale (FSS), WHO Disability Assessment Scale (DAS 2.0), health related quality of life (SF36) and International Physical Activity Questionnaire (IPAQ). RESULTS: Of 282 participants with confirmed diagnoses of muscle glycogenosis, 269 had GSD5. Of them 196 (73%) completed all questionnaires; for the others, the data were incomplete. The majority, 180 (67%) were currently working. Previous medical treatments included pain medication (23%) and rehabilitation treatment (60%). The carbohydrate-rich diet was reported to be beneficial for 68%, the low sucrose diet for 76% and the ketogenic diet for 88%. Almost all participants (93%) reported difficulties climbing stairs. The median FSS score was 5.22, indicating severe fatigue. The data from the WHODAS and IPAQ was not of sufficient quality to be interpreted. CONCLUSIONS: The EUROMAC registry have provided insight into the functional and social status of participants with GSD5: most participants are socially active despite limitations in physical and daily life activities. Regular physical activity and different dietary approaches may alleviate fatigue and pain.

A novel MYH7 mutation links congenital fiber type disproportion and myosin storage myopathy.

This study aimed to identify the genetic defect in a multigenerational family presenting an autosomal dominant myopathy with histological features of congenital fiber type disproportion. Linkage analysis and genetic sequencing identified, in all affected members of the family, the c.5807A>G heterozygous mutation in MYH7, which encodes the slow/ß-cardiac myosin heavy chain. This mutation causes skeletal but not cardiac involvement. Myosin heavy chain expression pattern was also characterized by immunohistochemistry, western blot and q-PCR in muscle biopsies from two patients aged 25 and 62, respectively. While only congenital fiber type disproportion was observed in the younger patient, older patient's biopsy presented aggregates of slow myosin heavy chains, in fiber sub-sarcolemmal region. These clinico-pathologic findings suggest a novel phenotype within the emerging group of hereditary myosin myopathies, which in this family presents typical characteristics of congenital fiber type disproportion in early stages and later evolves to myosin storage myopathy.