There are patients in whom features of both hyperKPP and PC are present. These diseases result from molecular alterations in the adult skeletal muscle sodium channel. [n.neurology.org]

This presentation is about different diseases which presents or are associated with myotonia. Referrences were taken from Bashir Katirji Neuromuscular textbook, continuum, and seminar of neurology journal. [slideshare.net]

The clinical presentation of patients varies depending on which nucleotide, codon, or amino acid changes, and the number of mutant exons. [annchildneurol.org]

SpaceNext50 Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space! [britannica.com]

The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment. [orpha.net]

• Weight Loss

  Other features include sinus tachycardia, weight loss, nausea, and vomiting. Thyrotoxic HypoKPP resolves without morbidity after treatment of the thyroid disease. [annalsofian.org]

• Ventricular Bigeminy

  […] tachycardia, and ventricular bigeminy. [translational-medicine.biomedcentral.com]

• Low Set Ears

  Distinctive physical findings include hypertelorism, micrognathia, low-set ears, high-arched or cleft palate, short stature, clinodactyly, syndactyly, and a broad nasal root. [humpath.com]

  Some have unusual facial and hand characteristics, such as short stature, clinodactyly (an inward curvature of the 5th fingers), scoliosis, widely spaced eyes, low-set ears, a broad forehead and a small jaw. [hkpp.org]

  They include low-set ears, hypertelorism, clinodactyly, and syndactyly. Bidirectional ventricular tachycardia is a frequent and potentially serious arrhythmia. [annalsofian.org]

  […] limb muscle contractions Spread from one muscle to another Episodes of contractions: Minutes to hours Duration of individual contractions: 5 to 30 seconds each Stimulus: Tapping on muscle Muscle size: Large Skeletal Short stature Face: Large nose & Low-set [neuromuscular.wustl.edu]

  Malformations include ocular hypertelorism, low-set ears, small mandible, scoliosis, fifth digit clinodactyly, syndactyly, short stature, and a broad forehead [162]. [mdpi.com]

• Proximal Muscle Weakness

  Proximal muscle weakness is associated with muscle discomfort and cramps and each episode lasts hours to days. The lower limbs are more involved than the upper limbs in a proximo-distal fashion. [annalsofian.org]

  Many patients with DM2 mutation present with prominent proximal muscle weakness, the so-called proximal myotonic myopathy. [15] Distal pattern of muscle weakness similar to DM1 can also be seen in patients with DM2. [bioline.org.br]

  In contrast to Thomsen’s disease, patients with autosomal-recessive myotonia congenita (Becker’s disease) have transient proximal muscle weakness. [clinicalgate.com]

  Slowly progressive proximal limb weakness n.a. [mdpi.com]

• Fracture

  […] episodes High mortality in infancy Skeletal Joint contractures Bent bone dysplasia: Campomelic-metaphyseal (Like Pyle disease ) Bowing of lower limbs Internal cortical thickening Wide metaphyses: Abnormal trabecular pattern Camptodactyly Spontaneous fractures [neuromuscular.wustl.edu]

  Many patients have suffered bone fractures from falling while paralyzed. [translational-medicine.biomedcentral.com]

  Skeletal evaluation shows growth failure and osteomalacia with pathologic fractures. This is frequently seen in hyperthyroid patients. It is most common in Asians, among whom the incidence is about 2%. [annalsofian.org]

• Muscular Atrophy

  Klin Wochenschr. 1885; 22: 489-491 Biemond A Daniels A.P Familial periodic paralysis and its transition into spinal muscular atrophy. [amjmed.com]

  atrophy; SPSMA: Scapuloperoneal spinal muscular atrophy; SR: sarcoplasmic reticulum; STRMK: Stormorken syndrome; TAM: Tubular aggregate myopathy). [mdpi.com]

• Leg Weakness

  At the age of 18 years after a period of prolonged sitting he experienced bilateral leg weakness that lasted for several hours and spontaneously resolved. [nature.com]

• Hypertelorism

  Distinctive physical findings include hypertelorism, micrognathia, low-set ears, high-arched or cleft palate, short stature, clinodactyly, syndactyly, and a broad nasal root. [humpath.com]

  They include low-set ears, hypertelorism, clinodactyly, and syndactyly. Bidirectional ventricular tachycardia is a frequent and potentially serious arrhythmia. [annalsofian.org]

  Malformations include ocular hypertelorism, low-set ears, small mandible, scoliosis, fifth digit clinodactyly, syndactyly, short stature, and a broad forehead [162]. [mdpi.com]

• Suggestibility

  The panel also suggested a need for a red flags list for easier NDM recognition, such as myotonia, myalgia, and, in some cases, increased serum creatine kinase levels. [emjreviews.com]

  The structure of electric eel NaV1.430 suggests that a mutation of R1451 disrupts its electrostatic interaction with E1373 (Fig. 6). [nature.com]

  These findings suggest that allelic variation may be an important modifier of disease progression in myotonia congenita. [clinicalgate.com]

  This suggests that pain is a frequent symptom that may have been previously under-recognized and possibly undertreated in the non-dystrophic myotonias. [medscape.com]

  Importantly, some studies suggest that in vitro results may be translated to the clinical setting. [content.iospress.com]

• Hunger

  There is no large difference between these two groups except that patients with no known mutation have attacks precipitated less by cold but more by hunger, are much more likely to have normal muscle biopsies, and show less decreased compound muscle action [wikidoc.org]

• Limb Weakness

  Periodic paralysis may be associated with progressive features of fixed limb weakness. [now.aapmr.org]

  Proximal muscle weakness is associated with muscle discomfort and cramps and each episode lasts hours to days. The lower limbs are more involved than the upper limbs in a proximo-distal fashion. [annalsofian.org]

  Facial weakness is mild in DM2, as is muscle wasting in the face and limbs. Weakness of neck flexors is frequent. Trouble arising from a squat is common, especially as the disease progresses. [clinicalgate.com]

  Generalised limb muscle weakness occurred once or twice per month and isolated lower limb weakness 4–5 times per month. The ability to swallow and speak was well preserved. [nature.com]

  Slowly progressive proximal limb weakness n.a. [mdpi.com]

A complete metabolic workup at 15 months of age was negative. [nature.com]

• Electromyography showing Myotonia

  While 90% show myotonia on electromyography, only 50% have percussion myotonia on examination. [annalsofian.org]

• Torsades De Pointes

  However, it can lead to arrhythmias, including torsades de pointes. Mexilitine treatment requires close monitoring with electrocardiography. [annalsofian.org]

• Ventricular Bigeminy

  […] tachycardia, and ventricular bigeminy. [translational-medicine.biomedcentral.com]

The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment. [orpha.net]

[…] be used to measure and monitor the effectiveness of drug treatment on symptoms over time. [emjreviews.com]

The treatment is usually given to manage the signs and symptoms and any complication that develops. [dovemed.com]

[…] begins with avoiding foods that contain large amounts of potassium; other treatments may include physical therapy (stretching or massages to help relax muscles) or certain medications (such as mexiletine, carbamazapine, or acetazolamide).[5170] For more [rarediseases.org]

Proximal myotonic myopathy: a syndrome with a favourable prognosis? J Neurol Sci. 2002; 193:89-96 Day JW, Ricker K, Jacobsen JF, Rasmussen LJ, Dick A, Kress W. Myotonic dystrophy type 2: molecular, diagnostic and clinical spectrum. [medigraphic.com]

PMID: 16931510 Prognosis Lehmann-Horn F, D'Amico A, Bertini E, Lomonaco M, Merlini L, Nelson KR, Philippi H, Siciliano G, Spaans F, Jurkat-Rott K Acta Myol 2017 Sep;36(3):125-134. [ncbi.nlm.nih.gov]

Early predictions of outcomes A precise phenotypic and genotypic diagnosis is of critcal importance to provide prognosis, determine the most appropriate therapeutic intervention, and for accurate genetic counseling. [now.aapmr.org]

[…] exercise May be associated with paresthesias Lasts 15 to 60 minutes: Occasionally hours or days Provoked by Exercise Potassium loading Cold environment Pregnancy Glucocorticoids Stress Ethanol Fasting Relieved by: Carbohydrate intake; Mild exercise Prognosis [neuromuscular.wustl.edu]

Etiology ACZ-responsive myotonia is a sodium muscle channelopathy due to missense mutations of the SCN4A gene, encoding the alpha subunit of the skeletal muscle voltage-gated sodium channel Nav1.4. [orpha.net]

(Etiology) Potassium-Aggravated Myotonia is caused by missense mutation(s) in SCN4A gene The SCN4A gene codes for the alpha subunit of the skeletal muscle voltage-gated channel Nav1.4 The proper functioning of this gene is crucial for the proper activation [dovemed.com]

PMID: 20298421 Etiology J Mol Neurosci 2017 Mar;61(3):312-314. Epub 2016 Dec 23 doi: 10.1007/s12031-016-0878-5. [ncbi.nlm.nih.gov]

Etiology Autosomal dominant and recessive myotonia congenita (MC) are associated with mutations of the chloride channel gene, CLCN1, in greater than 95% of cases. [now.aapmr.org]

Summary Epidemiology Prevalence is unknown. [orpha.net]

Epidemiological estimates have been provided for the German population. [wikidoc.org]

Other loci; Dominant 9 Epidemiology Most families: CAV3 mutation 1 family: 1q41 linkage CAV3 Genetics Caveolin-3 mutations: Missense R26Q: AD-RMD; HyperCKemia Asp27Glu: Variable phenotype, AD-RMD; Distal weakness; LGMD & Intrafamilial variation A45T: [neuromuscular.wustl.edu]

The Epidemiology of Neuromuscular Disorders: A Comprehensive Overview of the Literature. Journal of neuromuscular diseases 2015;2(1):73-85. Hughes MI, Hicks EM, Nevin NC, Patterson VH. [now.aapmr.org]

These advances have resulted in more accurate DNA-based diagnosis and have increased our understanding of cellular pathophysiology. This is leading to more tailored therapies for patients with these disorders. [go.gale.com]

These diseases have a heterogeneous pathophysiology. They (...) RYR1 5 August 2008 RYR1 gene codes for ryanodine receptor. The RYR1 gene on chromosome 19q, encodes for ryanodine receptor type 1. [humpath.com]

Pathophysiology The molecular mechanisms leading to the manifestations of DM2 are believed to be similar to that in DM1, and relate to a toxic effect of the abnormally expanded RNA that accumulates in the muscle nuclei (see previous section on Pathophysiology [clinicalgate.com]

This pathophysiological mechanism can lead to an initial burst of myotonia discharges and results in the symptom of stiffness. [annchildneurol.org]

People with this disease will continue to show a continuous burst of muscle tension (muscle stiffness) that prevents the muscles from relaxing normally. [acroscell.creative-bioarray.com]

Currently, Potassium-Aggravated Myotonia may not be preventable, since it is a genetic disorder. [dovemed.com]

Beginning in childhood or adolescence, people with this condition experience bouts of sustained muscle tensing (myotonia) that prevent muscles from relaxing normally. [rarediseases.oscar.ncsu.edu]

Beginning in childhood, people with this condition experience bouts of sustained muscle tensing (myotonia) that prevent muscles from relaxing normally. [medlineplus.gov]