Related Experiment Video
Updated: Jul 9, 2026
09:39
Modeling Myotonic Dystrophy 1 in C2C12 Myoblast Cells
Published on: July 29, 2016
[Eulenburg's paramyotonia congenita].
M Sallansonnet-Froment1, P Bounolleau, T De Greslan
1Service de Neurologie, Hôpital d'Instruction des Armées du Val-de-Grâce, Paris. froment.magali@wanadoo.fr
Revue Neurologique
|November 23, 2007
Summary
Paramyotonia congenita, a genetic muscle disorder, causes stiffness and weakness triggered by cold and exercise. A specific SCN4A gene mutation was identified in a patient, guiding preventive treatment strategies.
Area of Science:
- Neurology
- Genetics
- Molecular Biology
Background:
- Paramyotonia congenita is an inherited condition affecting muscle function.
- It is classified as a sodium channelopathy, stemming from mutations in the SCN4A gene.
Observation:
- A 38-year-old man experienced childhood-onset muscle stiffness and weakness.
- Symptoms were exacerbated by cold exposure and physical exertion, primarily affecting eyelids, hands, and limbs.
- Clinical and electrophysiological tests confirmed generalized myotonia.
Findings:
- Genetic analysis revealed an Arg1448Cys mutation in the SCN4A gene.
- This mutation is associated with the autosomal dominant inheritance pattern of the condition.
Implications:
- Paramyotonia congenita is non-progressive, emphasizing preventive management.
- Treatment options include membrane stabilizers (e.g., mexiletine) and acetazolamide.
- Caution is advised during anesthesia due to potential diaphragm involvement.
Related Concept Videos
01:11Alterations in Muscle Tone lll
Rigidity and myotonia are distinct abnormalities of muscle tone that affect resistance and relaxation during movement. Although both involve altered muscle contraction, they arise from different neurological and muscular mechanisms.CharacteristicsRigidity is characterized by uniform resistance to passive movement across the entire range, independent of speed, affecting flexors and extensors equally. It may appear as lead-pipe rigidity (smooth, constant resistance) or cogwheel rigidity...
01:12Alterations in Muscle Tone ll
Alterations in muscle tone are common manifestations of neurological disorders and reflect dysfunction within different nervous system regions. Spasticity, paratonia, and dystonia represent distinct forms of hypertonia, each with unique mechanisms, clinical features, and diagnostic importance.CharacteristicsSpasticity happens from upper motor neuron lesions and is characterized by velocity-dependent resistance to passive movement. Clinical features include:Exaggerated deep tendon reflexesClonus...
01:22Myasthenia Gravis ll: Pathophysiology
The disease process of myasthenia gravis begins at the neuromuscular junction, where antibodies attack key proteins needed for muscle activation. This immune reaction weakens signal transmission, leading to the characteristic muscle fatigue and weakness that define the condition.Immune-Mediated DamageIn most individuals, antibodies target acetylcholine receptors (AChRs) on the postsynaptic membrane of muscle cells. By blocking acetylcholine binding, these antibodies prevent the nerve signal...
01:15Myasthenia Gravis: Diagnostic Tests
Myasthenia gravis is an autoimmune condition affecting neuromuscular transmission, causing generalized weakness in skeletal muscles. Initial diagnoses rely on patients' signs, symptoms, and medical history. The challenge lies in distinguishing myasthenia from other muscular dystrophies. An important diagnostic feature is the significant improvement of symptoms after administering anticholinesterase inhibitors.
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
01:20Inborn Errors of Metabolism
Phenylketonuria (PKU) is a protein metabolism disorder characterized by high blood levels of the amino acid phenylalanine. This results from a mutation in the gene responsible for phenylalanine hydroxylase, an enzyme that converts phenylalanine into tyrosine. When this enzyme is deficient, phenylalanine builds up in the blood, leading to symptoms such as vomiting, rashes, seizures, growth deficiency, and severe mental retardation. An early diagnosis and a diet restricting phenylalanine intake...
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy, or HCM, is an autosomal dominant genetic disorder characterized by asymmetric left ventricular hypertrophy without ventricular dilation. It is more common in men and is typically diagnosed in young, athletic adults.EtiologyHCM is primarily genetic and is caused by mutations in genes encoding sarcomeric proteins. Researchers have identified over 1400 mutations across at least 11 different genes. Among these, the most frequently occurring mutations are found in the...