1. Clinical, morphological and genetic characterization of Brody disease: an international study of 40 patients
- Author
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Joery P. Molenaar, Gaetano Vattemi, E. Kamsteeg, Benno Küsters, Damien Sternberg, Valeria Guglielmi, Amaia Martínez-Arroyo, K. Suetterlin, Corrie E. Erasmus, Barbara W. Brandom, Juergen Seeger, Susan Treves, Nicol C. Voermans, Thierry Kuntzer, Jérôme Franques, Mark E. Roberts, Roberto Fernández-Torrón, Frédéric Chevessier, Jamie I Verhoeven, Guillaume Bassez, Baziel G.M. van Engelen, Anthony Behin, Lucie Guyant-Maréchal, Richard J. Rodenburg, Savine Vicart, Jean Mathieu, Bruno Eymard, Armelle Magot, Michael G. Hanna, Yann Péréon, and M.M.J. Snoeck
- Subjects
0301 basic medicine ,Adult ,Male ,medicine.medical_specialty ,Adolescent ,Myotonia Congenita ,phenotype ,genotype ,Calcium-Transporting ATPases/genetics ,Child ,Female ,Humans ,Muscle, Skeletal/metabolism ,Muscle, Skeletal/physiopathology ,Muscular Diseases/genetics ,Mutation/genetics ,Myotonia Congenita/genetics ,Phenotype ,Sarcoplasmic Reticulum/metabolism ,Young Adult ,ATP2A1 ,Brody disease ,calcium ,Other Research Donders Center for Medical Neuroscience [Radboudumc 0] ,Physical examination ,Calcium-Transporting ATPases ,Sensory disorders Donders Center for Medical Neuroscience [Radboudumc 12] ,03 medical and health sciences ,0302 clinical medicine ,Atrophy ,Muscular Diseases ,Internal medicine ,medicine ,Myopathy ,Muscle, Skeletal ,Muscle contracture ,Muscle biopsy ,medicine.diagnostic_test ,business.industry ,Malignant hyperthermia ,Metabolic Disorders Radboud Institute for Molecular Life Sciences [Radboudumc 6] ,Original Articles ,Myotonia ,medicine.disease ,Disorders of movement Donders Center for Medical Neuroscience [Radboudumc 3] ,Editor's Choice ,Sarcoplasmic Reticulum ,030104 developmental biology ,Mutation ,Neurology (clinical) ,medicine.symptom ,Contracture ,business ,030217 neurology & neurosurgery - Abstract
Brody disease is a rare myopathy characterized by exercise-induced muscle stiffness caused by mutations in the ATP2A1 gene. In the largest cohort of Brody patients to date, Molenaar et al. clarify the phenotype and diagnostic possibilities to help improve understanding and recognition of this distinct myopathy., Brody disease is an autosomal recessive myopathy characterized by exercise-induced muscle stiffness due to mutations in the ATP2A1 gene. Almost 50 years after the initial case presentation, only 18 patients have been reported and many questions regarding the clinical phenotype and results of ancillary investigations remain unanswered, likely leading to incomplete recognition and consequently under-diagnosis. Additionally, little is known about the natural history of the disorder, genotype-phenotype correlations, and the effects of symptomatic treatment. We studied the largest cohort of Brody disease patients to date (n = 40), consisting of 22 new patients (19 novel mutations) and all 18 previously published patients. This observational study shows that the main feature of Brody disease is an exercise-induced muscle stiffness of the limbs, and often of the eyelids. Onset begins in childhood and there was no or only mild progression of symptoms over time. Four patients had episodes resembling malignant hyperthermia. The key finding at physical examination was delayed relaxation after repetitive contractions. Additionally, no atrophy was seen, muscle strength was generally preserved, and some patients had a remarkable athletic build. Symptomatic treatment was mostly ineffective or produced unacceptable side effects. EMG showed silent contractures in approximately half of the patients and no myotonia. Creatine kinase was normal or mildly elevated, and muscle biopsy showed mild myopathic changes with selective type II atrophy. Sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA) activity was reduced and western blot analysis showed decreased or absent SERCA1 protein. Based on this cohort, we conclude that Brody disease should be considered in cases of exercise-induced muscle stiffness. When physical examination shows delayed relaxation, and there are no myotonic discharges at electromyography, we recommend direct sequencing of the ATP2A1 gene or next generation sequencing with a myopathy panel. Aside from clinical features, SERCA activity measurement and SERCA1 western blot can assist in proving the pathogenicity of novel ATP2A1 mutations. Finally, patients with Brody disease may be at risk for malignant hyperthermia-like episodes, and therefore appropriate perioperative measures are recommended. This study will help improve understanding and recognition of Brody disease as a distinct myopathy in the broader field of calcium-related myopathies.
- Published
- 2020