Myology research highlights

Myosin myopathies comprise a group of inherited diseases caused by mutations in myosin heavy chain (MyHC) genes. Homozygous or compound heterozygous truncating MYH2 mutations have been demonstrated to cause recessive myopathy with ophthalmoplegia, mild-to-moderate muscle weakness and complete lack of type 2A muscle fibers. In this study, the authors describe for the first time the … [Read more]

McArdle disease is a nonlysosomal glycogenosis that classically manifests with exercise-induced pain from childhood. Fixed weakness may occur from the fifth decade and is typically mild and located around the shoulder girdle. Here, the authors describe a 61-year-old man with exercise-induced pain from a young age and a 3-year history of weight loss and an … [Read more]

Most evidence supporting the benefit of thymectomy in juvenile myasthenia gravis (JMG) is extrapolated from adult studies, with only little data concerning paediatric populations. Here, the authors evaluate the outcome of children with generalized JMG who underwent thymectomy between 1996 and 2010 at 2 tertiary paediatric neurology referral centres in the United Kingdom. Twenty patients … [Read more]

A variable proportion of patients with generalized myasthenia gravis (MG) have autoantibodies to muscle specific tyrosine kinase (MuSK). During development, agrin, released from the motor nerve, interacts with low density lipoprotein receptor-related protein-4 (LRP4), which then binds to MuSK; MuSK interaction with the intracellular protein Dok7 results in clustering of the acetylcholine receptors (AChRs) on … [Read more]

This study aimed to identify mutations in the inverted formin-2 (INF2) gene in patients with Charcot-Marie-Tooth (CMT) disease combined with focal segmental glomerulosclerosis (FSGS) in order to expand the genetic and phenotypic spectrum. INF2 was sequenced in 5 patients with CMT disease and FSGS. Mutations were subsequently screened in family members of the index patient … [Read more]

Charcot-Marie-Tooth (CMT) neuropathies represent a heterogeneous group of peripheral nerve disorders affecting 1 in 2500 persons. One variant, CMT1A, is a primary Schwann cell disorder, and represents the single most common variant. In previous studies the authors showed that neurotrophin-3 (NT-3) improved the tremblerJ (TrJ) mouse and also showed efficacy in CMT1A patients. Long-term treatment … [Read more]

Core myopathies (CM), the main non-dystrophic myopathies in childhood, remain genetically unexplained in many cases. Heart disease is not considered part of the typical CM spectrum. No congenital heart defect has been reported, and childhood-onset cardiomyopathy has been documented in only two CM families with homozygous mutations of the TTN gene. TTN encodes titin, a … [Read more]

In patients with myotonic dystrophy type 1 (DM1), the mechanisms underlying sudden cardiac death, which occurs in up to 1/3 of patients, are unclear. To study the potential role of Brugada syndrome in ventricular tachyarrhythmias and sudden death in DM1 patients, 914 adult patients included in the DM1 Heart Registry during 2000-2009 were screened for … [Read more]

Myotonic dystrophy is the most common adult muscle dystrophy. In view of emerging therapies, which use animal models as a proof of principle, the development of reliable outcome measures for in vivo longitudinal study of mouse skeletal muscle function is becoming crucial. To satisfy this need, the authors have developed a device to measure ankle … [Read more]

Duchenne muscular dystrophy (DMD) is one of the most common hereditary degenerative neuromuscular diseases, caused by mutations in the dystrophin gene. Two studies describing growth patterns and psychomotor development in DMD are presented. In the first retrospective study, the authors describe growth and psychomotor development of patients with DMD and to detect a possible genotype-phenotype … [Read more]