A 25-year-old man presented with a 10-year history of difficulty in relaxing his muscles. He was bodybuilding champion in his city without doing any exercise. Neurologic examination revealed well-formed skeletal muscles (first part of the video: http://ijnl.tums.ac.ir/public/891-725-1-Part1.mov) and myotonia most prominent in the eyes (a lag in opening the eyes after forceful closure) and hands...

The myotonic disorders are a heterogeneous group of genetically determined diseases that are unified by the presence of myotonia, which is defined as failure of muscle relaxation after activation. The presentation of these disorders can range from asymptomatic electrical myotonia, as seen in some forms of myotonia congenita (MC), to severe disability with muscle weakness, cardiac conduction def...

Background. Dystrophic myotonia type 1 (DM1) is the most common muscular dystrophy in patients of any age. Myotonia “delayed relaxation muscle” leading symptom DM1 and can occur at time after onset disease. symptoms electrical registration are delayed with congenital infantile forms DM1. This makes it difficult to diagnose prevent fatal complications these a timely manner. Objective: presentati...

OBJECTIVES To define a new type of dominant myotonic muscle disorder and to identify the gene lesion. DESIGN Case series, clinical examination and electromyography, measurements of grip force and relaxation time, and DNA analysis to probe for mutation in the gene for the skeletal muscle sodium channel. SETTING Outpatient clinic and home. PATIENTS Three families studied; all together, 17 a...

congenital recessive myotonia is a rare genetic disorder caused by mutations in clcn1, which codes for the main skeletal muscle chloride channel clc-1. more than 120 mutations have been found in this gene. the main feature of this disorder is muscle membrane hyperexcitability. here, we report a 59-year male patient suffering from congenital myotonia. he had transient generalized myotonia, which...

We report a family of a brother and sister of myotonia congenita, conforming to autosomal recessive transmission (Becker's variety). To the best of our knowledge, no account of a family of autosomal recessive myotonia (Becker's disease), has earlier been reported from India.

in resealed fiber segments from patients with recessive generalized myotonia (Becker) and in intact fibers from normal muscles which were bathed in 9-anthracene carboxylic acid. The tests were performed in vitro on small bundles of 100 fibers or less. Electromyographic activity and contractile force were measured simultaneously. The relaxation of rested-state twitches and tetani was slowed and ...

The cause of increased excitability in autosomal dominant myotonia congenita (MyC) was studied in resealed greater than 3-cm long segments of muscle fibres from eight patients. Three hours after biopsy only about 50% of the fibre segments had regained a normal resting potential. This differs from our experiences with normal muscle or other disorders of myotonia (e.g. recessive generalized myoto...

Recessive myotonia congenita (Becker) is genetically linked to HUMCLC, the gene encoding the muscular chloride channel, localized on chromosome 7q35. Three point mutations have so far been reported in HUMCLC, one causing recessive Becker-type myotonia, the others causing the clinically similar Thomsen-type myotonia, which is inherited as a dominant trait. We report a homozygous patient having a...

Myotonia is a symptom of various genetic and acquired skeletal muscular disorders and is characterized by hyperexcitability of the sarcolemma. Here, we have performed a comparative proteomic study of the genetic mouse models ADR, MTO and MTO*5J of human congenital myotonia in order to determine myotonia-specific changes in the global protein complement of gastrocnemius muscle. Proteomic analyse...