Congenital myasthenia
Synonyms and keywords:

# Special consideration when adding information from observational studies

# Overview

# Historical Perspective
Congenital Myasthenia was first discovered by Andrew G. Engel, an American Neurologist from Mayo Clinic, Rochester, in 1988.
The association between genetic mutations and Congenital Myasthenia was made during the years 2012-2015.
In 1997, CHRNA1 mutations were first implicated in the pathogenesis of Congenital Myasthenia.
If clinical examination fails to establish diagnosis, exome sequencing is another useful tool that aids the diagnosis.

# Classification
There is no established system for the classification of .
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 may be classified according to  into  subtypes/groups: , , , and .
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 may be classified into  subtypes based on , , and .
 may be classified into several subtypes based on , , and .
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Based on the duration of symptoms,  may be classified as either acute or chronic.
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If the staging system involves specific and characteristic findings and features:
According to the , there are  stages of  based on the , , and . Each stage is assigned a  and a  that designate the  and .
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The staging of  is based on the .
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There is no established system for the staging of .

# Pathophysiology
The exact pathogenesis of  is not fully understood.
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It is thought that  is the result of / is mediated by / is produced by / is caused by either , , or .
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 is usually transmitted via the  route to the human host.
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Following transmission/ingestion, the  uses the  to invade the  cell.
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 arises from s, which are  cells that are normally involved in .
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The progression to  usually involves the .
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The pathophysiology of  depends on the histological subtype.

# Causes
Disease name] may be caused by , , or .
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Common causes of  include , , and .
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The most common cause of  is . Less common causes of  include , , and .
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The cause of  has not been identified. To review risk factors for the development of , click here.

# Differentiating ((Page name)) from other Diseases
 must be differentiated from other diseases that cause , , and , such as , , and .
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 must be differentiated from , , and .

# Epidemiology and Demographics
The incidence/prevalence of  is approximately  per 100,000 individuals worldwide.
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In , the incidence/prevalence of  was estimated to be  cases per 100,000 individuals worldwide.
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In , the incidence of  is approximately  per 100,000 individuals with a case-fatality rate of %.
Patients of all age groups may develop .
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The incidence of  increases with age; the median age at diagnosis is  years.
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 commonly affects individuals younger than/older than  years of age.
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 is usually first diagnosed among .
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 commonly affects .
There is no racial predilection to .
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 usually affects individuals of the  race.  individuals are less likely to develop .
 affects men and women equally.
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 are more commonly affected by  than . The  to  ratio is approximately  to 1.
The majority of  cases are reported in .
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 is a common/rare disease that tends to affect  and .

# Risk Factors
There are no established risk factors for .
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The most potent risk factor in the development of  is . Other risk factors include , , and .
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Common risk factors in the development of  include , , , and .
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Common risk factors in the development of  may be occupational, environmental, genetic, and viral.

# Screening
There is insufficient evidence to recommend routine screening for .
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According to the , screening for  is not recommended.
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According to the , screening for  by  is recommended every  among patients with , , and .

# Natural History, Complications, and Prognosis
If left untreated, % of patients with  may progress to develop , , and .
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Common complications of  include , , and .
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Prognosis is generally excellent/good/poor, and the 1/5/10-year mortality/survival rate of patients with  is approximately %.

# Diagnosis

## Diagnostic Study of Choice
The diagnosis of  is made when at least  of the following  diagnostic criteria are met: , , , and .
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The diagnosis of  is based on the  criteria, which include , , and .
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The diagnosis of  is based on the  definition, which includes , , and .
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There are no established criteria for the diagnosis of .

## History and Symptoms
The majority of patients with  are asymptomatic.
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The hallmark of  is . A positive history of  and  is suggestive of . The most common symptoms of  include , , and . Common symptoms of  include , , and . Less common symptoms of  include , , and .

## Physical Examination
Patients with  usually appear . Physical examination of patients with  is usually remarkable for , , and .
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Common physical examination findings of  include , , and .
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The presence of  on physical examination is diagnostic of .
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The presence of  on physical examination is highly suggestive of .

## Laboratory Findings
An elevated/reduced concentration of serum/blood/urinary/CSF/other  is diagnostic of .
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Laboratory findings consistent with the diagnosis of  include , , and .
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 is usually normal among patients with .
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Some patients with  may have elevated/reduced concentration of , which is usually suggestive of .
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There are no diagnostic laboratory findings associated with .

## Electrocardiogram
There are no ECG findings associated with .
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An ECG may be helpful in the diagnosis of . Findings on an ECG suggestive of/diagnostic of  include , , and .

## X-ray
There are no x-ray findings associated with .
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An x-ray may be helpful in the diagnosis of . Findings on an x-ray suggestive of/diagnostic of  include , , and .
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There are no x-ray findings associated with . However, an x-ray may be helpful in the diagnosis of complications of , which include , , and .

## Echocardiography or Ultrasound
There are no echocardiography/ultrasound  findings associated with .
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Echocardiography/ultrasound  may be helpful in the diagnosis of . Findings on an echocardiography/ultrasound suggestive of/diagnostic of  include , , and .
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There are no echocardiography/ultrasound  findings associated with . However, an echocardiography/ultrasound  may be helpful in the diagnosis of complications of , which include , , and .

## CT scan
There are no CT scan findings associated with .
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 CT scan may be helpful in the diagnosis of . Findings on CT scan suggestive of/diagnostic of  include , , and .
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There are no CT scan findings associated with . However, a CT scan may be helpful in the diagnosis of complications of , which include , , and .

## MRI
There are no MRI findings associated with .
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 MRI may be helpful in the diagnosis of . Findings on MRI suggestive of/diagnostic of  include , , and .
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There are no MRI findings associated with . However, a MRI may be helpful in the diagnosis of complications of , which include , , and .

## Other Imaging Findings
There are no other imaging findings associated with .
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 may be helpful in the diagnosis of . Findings on an  suggestive of/diagnostic of  include , , and .

## Other Diagnostic Studies
There are no other diagnostic studies associated with .
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 may be helpful in the diagnosis of . Findings suggestive of/diagnostic of  include , , and .
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Other diagnostic studies for  include , which demonstrates , , and , and , which demonstrates , , and .

# Treatment

## Medical Therapy
There is no treatment for ; the mainstay of therapy is supportive care.
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Supportive therapy for  includes , , and .
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The majority of cases of  are self-limited and require only supportive care.
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 is a medical emergency and requires prompt treatment.
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The mainstay of treatment for  is .
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The optimal therapy for  depends on the stage at diagnosis.
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 is recommended among all patients who develop .
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Pharmacologic medical therapy is recommended among patients with , , and .
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Pharmacologic medical therapies for  include (either) , , and/or .
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Empiric therapy for  depends on  and .
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Patients with  are treated with , whereas patients with  are treated with .

## Surgery
Surgical intervention is not recommended for the management of .
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Surgery is not the first-line treatment option for patients with . Surgery is usually reserved for patients with either , , and 
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The mainstay of treatment for  is medical therapy. Surgery is usually reserved for patients with either , , and/or .
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The feasibility of surgery depends on the stage of  at diagnosis.
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Surgery is the mainstay of treatment for .

## Primary Prevention
There are no established measures for the primary prevention of .
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There are no available vaccines against .
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Effective measures for the primary prevention of  include , , and .
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 vaccine is recommended for  to prevent . Other primary prevention strategies include , , and .

## Secondary Prevention
There are no established measures for the secondary prevention of .
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Effective measures for the secondary prevention of  include , , and .