Presentation
We present a case of congenital myasthenic syndrome with I336T choline acetyltransferase mutation who presented with numerous attacks of respiratory distress in the infancy period. [ncbi.nlm.nih.gov]
Entire Body System
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Poor Growth
Symptoms at presentation included mild gross motor development delay (7/10), speech articulation difficulty (5/10), and respiratory and feeding difficulties resulting in poor growth in 7 of 10 children. [ncbi.nlm.nih.gov]
Course
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Severe Clinical Course
CONCLUSIONS: We expand the phenotype of congenital myasthenic syndromes with MUSK mutations, describing a more severe clinical course with prenatal onset. [ncbi.nlm.nih.gov]
Cardiovascular
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Left Ventricular Dysfunction
Patient 1 had a broader phenotype, including learning difficulties and left ventricular dysfunction. Electrophysiologic studies were typical for a presynaptic defect. [ncbi.nlm.nih.gov]
Musculoskeletal
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Neck Muscle Weakness
Our observations indicate that founder Roma mutation 1267delG leads to a phenotype further characterized by ophthalmoplegia, bilateral ptosis, and good response to pyridostigmine and 3,4-DAP; but also by facial weakness, bulbar symptoms, neck muscle weakness [ncbi.nlm.nih.gov]
All affected patients have limb-girdle weakness with lesser facial and neck muscle weakness but a few have severe bulbar weakness and few have significant limitation of the eye movements.36,37 The clinical course is mild to severe. [rarediseases.org]
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Muscle Weakness Congenital
That defect causes muscle weakness. Congenital myasthenic syndromes may affect your nerve cells (presynaptic), your muscle cells (postsynaptic), or the space between your nerve and muscle cells (synaptic). [mayoclinic.org]
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Calf Hypertrophy
Fluctuating muscle weakness, myalgia and calf hypertrophy were the major complaints. Myogenic changes on electromyography and marked attenuation on 3 Hz repetitive nerve stimulation were observed in all patients. [ncbi.nlm.nih.gov]
Neurologic
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Slurred Speech
Children can be teased or criticised for their droopy eyes, squint, slurred speech and quiet voice and symptoms can vary from day to day and time to time. It is therefore important that they are listened to and offered appropriate support. [ro-mda.blogspot.de]
In some patients with CMS, the weakness is confined to muscles supplied (innervated) by the cranial nerves causing double vison, droopy eyelids (eyelid ptosis), facial weakness, hypernasal or slurred speech, and swallowing difficulties. [rarediseases.org]
Workup
For developmental delay, she has been evaluated by the Pediatric Neurology and Medical Genetics units and her workup is as follows: Tandem Mass Spectrometry (TMS), urine Gas Chromatography–Mass Spectrometry (GC-MS), Microarray Comparative Genomic Hybridization [degruyter.com]
X-Ray
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Normal Chest X-Ray
CMS should be suspected in patients with no pathological findings on the physical examination, and normal chest X-rays. [ncbi.nlm.nih.gov]
Treatment
Treatment was partly effective; one patient was asymptomatic with 3,4-diaminopyridine treatment. [ncbi.nlm.nih.gov]
Prognosis
However, the overall clinical prognosis is good since the vast majority of patients recovered their pre-pregnancy clinical status six months after the delivery. [ncbi.nlm.nih.gov]
Prognosis - Congenital myasthenic syndromes Severity and course of disease are highly variable, ranging from minor symptoms (e.g., mild exercise intolerance) to progressive disabling weakness. [checkorphan.org]
[…] mutations identified are associated with a spectrum of clinical symptoms ranging from very severe lethal forms at birth to CMS with apneic episodes in newborns, who are often wrongly diagnosed as suffering from encephalopathy or even epilepsy, but whose prognosis [icm-institute.org]
[…] of the clinical aspects of the congenital myasthenic syndromes, describes their historical aspects and current classification, summarizes general and specific features of the different disorders, and considers their pathophysiology, pathogenesis, and prognosis [medlink.com]
Therefore, a definitive genetic diagnosis is important and guides treatment, prognosis and genetic counselling. [pn.bmj.com]
Etiology
The muscle biopsy with extensive studies revealed no obvious etiologies. His muscle weakness rapidly worsened, requiring a wheelchair for daily activities. [ncbi.nlm.nih.gov]
These disorders are distinguishable from myasthenia gravis (MG) in the etiology of the transmission defect; while the transmission defect in MG is caused by antibodies against the acetylcholine receptor, CMS is caused by genetic presynaptic, synaptic, [webeye.ophth.uiowa.edu]
Definition/etiology : Congenital myasthenic syndromes (CMS) are a group of NMJ diseases caused by genetic defects of muscle end-plate molecules (specific proteins) involved in efficient neuromuscular transmission. [sites.google.com]
CMS diagnosis typically depends on a combination of factors, including clinical presentation, family history, genetic etiology, negative anti-ACh and anti-MuSK serum studies, and decremental electromyographic findings (PMID: 23622369). [invitae.com]
Epidemiology
Abstract The objective of the study was to evaluate the epidemiology of patients with congenital myasthenic syndrome (CMS) in Israel. [ncbi.nlm.nih.gov]
Differences from Myasthenia Gravis 12 LEMS never begins with ocular weakness LEMS usually has weakness in Legs Arms LEMS Subgroups 5 LEMS without neoplasm (SCLC) Epidemiology Male (50%) Female (50%) Median age: 49.5 years 40% of LEMS Weakness More confined [neuromuscular.wustl.edu]
Epidemiology : 2:1 male predominance. Onset: fetal life to early adulthood. Sx are present at birth in most forms but may go unrecognized until adolescence or adulthood, particularly when progression is gradual and clinical expression is mild. [sites.google.com]
Epidemiology Congenital myasthenic syndromes are rare; the prevalence of genetically confirmed cases in the UK is at least 3.8 per million. [pn.bmj.com]
Pathophysiology
Altogether, this mouse model provides new insight into the pathophysiology of congenital myasthenia and serves as a new tool for deciphering signaling pathways induced by excitotoxicity at peripheral synapses. Copyright 2011 Elsevier Inc. [ncbi.nlm.nih.gov]
Rapid advances in molecular genetics and correlation of molecular biology with microphysiology, morphologic studies, clinical electrophysiology, and clinical observations have led to a better understanding of the pathophysiology of congenital myasthenic [journals.lww.com]
Genetic heterogeneity and pathophysiological mechanisms in congenital myasthenic syndromes. Eur J Paediatr Neurol. 2011 May;15(3):189-96. doi: 10.1016/j.ejpn.2011.03.006. Epub 2011 Apr 17. Review. [ghr.nlm.nih.gov]
Prevention
Clinical trials Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this disease. Congenital myasthenic syndromes care at Mayo Clinic Nov. 19, 2016 References Engel AG, et al. [mayoclinic.org]
Finally, rare cases of endplate AD could stem from defects in the basal lamina that prevent the binding of ColQ. [jamanetwork.com]
Prevention - Congenital myasthenic syndromes Diagnosis - Congenital myasthenic syndromes The diagnosis of CMS is based on clinical findings, a decremental EMG response of the compound muscle action potential (CMAP) on low-frequency (2-3 Hz) stimulation [checkorphan.org]
If diagnosed early, CMS can be treated and prevented, to some extent, with medication. Almost all children with CMS will be able to walk independently and it does not affect intellect in any way. [ro-mda.blogspot.de]
If diagnosed early, CMS can be treated and prevented to some extent with medication. Almost all children with CMS will be able to walk independently and it does not affect intellect in any way. [musculardystrophyuk.org]