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[Aims] Recessive variants in CAPN3 gene are the cause of the commonest form of autosomal recessive limb girdle muscle dystrophy. However, two distinct in-frame deletions in CAPN3 (NM_000070.3:c.643_663del21 and c.598_621del15) and more recently, Gly445Arg and Arg572Pro substitutions have been linked to autosomal dominant (AD) forms of calpainopathy. We report 21 affected individuals from seven unrelated families presenting with an autosomal dominant form of muscular dystrophy associated with five different heterozygous missense variants in CAPN., [Methods] We have used massively parallel gene sequencing (MPS) to determine the genetic basis of a dominant form of limb girdle muscular dystrophy in affected individuals from seven unrelated families., [Results] The c.700G> A, [p.(Gly234Arg)], c.1327T> C [p.(Ser443Pro], c.1333G> A [p.(Gly445Arg)], c.1661A> C [p.(Tyr554Ser)] and c.1706T> C [p.(Phe569Ser)] CAPN3 variants were identified. Affected individuals presented in young adulthood with progressive proximal and axial weakness, waddling walking and scapular winging or with isolated hyperCKaemia. Muscle imaging showed fatty replacement of paraspinal muscles, variable degrees of involvement of the gluteal muscles, and the posterior compartment of the thigh and minor changes at the mid-leg level. Muscle biopsies revealed mild myopathic changes. Western blot analysis revealed a clear reduction in calpain 3 in skeletal muscle relative to controls. Protein modelling of these variants on the predicted structure of calpain 3 revealed that all variants are located in proximity to the calmodulin-binding site and are predicted to interfere with proteolytic activation., [Conclusions] We expand the genotypic spectrum of CAPN3-associated muscular dystrophy due to autosomal dominant missense variants., This study was funded in part by Instituto de Salud Carlos III through the project PI14/00738 to M. O. (co-funded by European Regional Development Fund. ERDF, a way to build Europe). We thank CERCA Programme / Generalitat de Catalunya for institutional support NGL (APP1117510) and GR (APP1122952) are supported by the Australian National Health and Medical Research Council (NHMRC). This work is also funded by an NHMRC Project Grant (APP1080587).

Resumen: Introducción: El conocimiento del alcance socioeconómico de la patología neuromuscular es esencial para la planificación de recursos y la concienciación social. Desarrollo: Se ha realizado una revisión de los datos publicados hasta el momento sobre epidemiología, mortalidad, dependencia e impacto sociosanitario de la esclerosis lateral amiotrófica y las enfermedades neuromusculares en España. Además, se ha recogido cómo está organizada la atención neurológica en estos pacientes. Conclusiones: La patología neuromuscular constituye un grupo muy heterogéneo de enfermedades, algunas de las cuales se consideran raras por su baja frecuencia. Esta patología supone entre el 2,8 y el 18% de los motivos de consulta en un Servicio de Neurología. En España, las cifras de prevalencia e incidencia de esclerosis lateral amiotrófica son similares a otros países; sin embargo, se desconoce el número de pacientes con otras enfermedades neuromusculares. Son enfermedades crónicas, progresivas y debilitantes, lo que condiciona una importante discapacidad y dependencia. Esto repercute directamente en los costes sanitarios y sociales asociados a la enfermedad. Se ha calculado que el coste de un paciente con esclerosis lateral amiotrófica o enfermedad de Duchenne se acerca a los 50.000 euros anuales. La patología neuromuscular tiene una gran complejidad etiológica, diagnóstica y pronóstica, y requiere un manejo multidisciplinar. Las Unidades especializadas deben ser las encargadas del seguimiento de estos pacientes. Abstract: Introduction: A thorough knowledge of the socioeconomic scope of neuromuscular disease is essential for managing resources and raising social awareness. Development: Our group reviewed current data on the epidemiology, mortality and dependence rates, and socioeconomic impact of amyotrophic lateral sclerosis and neuromuscular diseases in Spain. We also recorded how neurological care for these patients is organised. Conclusions: Neuromuscular disorders are a very heterogeneous group of diseases, and some are very rare. These disorders account for between 2.8% and 18% of the total motives for a neurological consultation. In Spain, prevalence and incidence figures for amyotrophic lateral sclerosis are similar to those in other countries; however, figures for patients with other neuromuscular diseases are not known. Since the diseases are chronic, progressive, and debilitating, they cause considerable disability and dependence, which in turn directly affects healthcare and social costs associated with the disease. The costs generated by one patient with amyotrophic lateral sclerosis or Duchenne disease have been calculated at about 50 000 euros per year. Neuromuscular disease shows aetiological, diagnostic, and prognostic complexity, and it requires multidisciplinary management. Follow-up for these patients should be entrusted to specialised units. Palabras clave: Dependencia, Epidemiología, Enfermedades neuromusculares, Esclerosis lateral amiotrófica, España, Impacto económico, Keywords: Dependence, Epidemiology, Neuromuscular diseases, Amyotrophic lateral sclerosis, Spain, Economic impact