Myasthenia Gravis

The myasthenia gravis test can provide an accurate reading of the presence of anti–acetylcholine receptor (AChR) antibodies (Ab) and is reliable for diagnosing autoimmune myasthenia gravis. Order from Ulta Lab Tests to screen, analyze, and monitor for the muscle weakness condition myasthenia gravis with confidential results available in 24 to 48 hours online.      

Below the list of tests is a guide that explains and answers your questions on what you need to know about myasthenia gravis tests, along with information on myasthenia gravis, signs, symptoms, and diagnosis.


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Myasthenia Gravis (MG) is a neuromuscular disorder characterized by muscle weakness, most commonly due to autoantibody-mediated loss of functional acetylcholine receptors (AChR) in the neuromuscular junction. This assay aids in the differential diagnosis of MG-like muscle weakness, in differentiating between generalized MG and ocular MG, and in monitoring therapeutic response. If binding antibodies are negative, assays for blocking and modulating antibodies should be considered.

Myasthenia gravis (MG) is a neuromuscular disorder characterized by muscle weakness, most commonly due to autoantibody-mediated loss of functional acetylcholine receptors (AChR) in the neuromuscular junction. This assay is most useful when the acetylcholinesterase receptor modulating antibodies are positive. The assay for blocking antibodies is useful in monitoring response to therapy.

Myasthenia gravis (MG) is a neuromuscular disorder characterized by muscle weakness, most commonly due to autoantibody-mediated loss of functional acetylcholine receptors (AChR) in the neuromuscular junction. Modulating Antibody to AChR causes weakness by inhibiting or modulating binding to the receptors.

Antinuclear antibodies are associated with rheumatic diseases including Systemic Lupus Erythematous (SLE), mixed connective tissue disease, Sjogren's syndrome, scleroderma, polymyositis, CREST syndrome, and neurologic SLE. 

Reflex Information: If ANA Screen, IFA is positive, then ANA Titer and Pattern will be performed at an additional charge.


A synthetic circular peptide containing citrulline called CCP IgG (cyclic citrullinated peptide) has been found to be better at discriminating Rheumatoid Arthritis patients from other patients than either the perinuclear autoantibody test or the test for rheumatoid factor. Approximately 70% of patients with Rheumatoid Arthritis are positive for Anti-CCP IgG, while only about 2% of random blood donors and disease controls subjects are positive.

Useful in the diagnosis of Myasthenia Gravis

Myasthenia Gravis is a neurological disorder characterized by a decrease in acetylcholine receptors. Patients exhibit skeletal muscle weakness and fatigability. Approximately 80% of patients with Myasthenia Gravis, excluding ocular involvement only, have detectable acetylcholine receptor antibody.

Acetylcholine Receptor Binding Antibody
Acetylcholine Receptor Blocking Antibody
Acetylcholine Receptor Modulating Antibody


Most Popular
Elevated RF is found in collagen vascular diseases such as SLE, rheumatoid arthritis, scleroderma, Sjögren's Syndrome, and in other conditions such as leprosy, tuberculosis, syphilis, malignancy, thyroid disease and in a significant percentage of otherwise normal elderly patients.


Voltage-Gated Calcium Channel (VGCC) Type N Antibody

Clinical Significance

N-type calcium channel antibodies are more highly associated with primary lung cancer than P/Q-type. One or all of the autoantibodies in the myasthenia gravis (MG)/LEMS evaluation can occur with neoplasia without evidence of neurological impairment. One or both calcium channel antibodies (P/Q and N) can occur with paraneoplastic and idiopathic cerebellar ataxia, encephalomyeloneuropathies, and autonomic neuropathy. Classical symptoms of LEMS include proximal muscle weakness, fatigability, dry mouth and impotence. When presentation is further complicated with oculobulbar weakness, these symptoms can easily be misinterpreted as MG. However, because VGCC antibodies are positive in only approximately 5% of MG patients, the measurement of these antibodies is very useful in distinguishing LEMS from MG.

Alternative Name(s) 

N-VGCC,NCC



Myasthenia gravis (MG) is a chronic (long-term) autoimmune disorder where the body’s immune system blocks communication between nerves and skeletal muscles. As a result, muscle fibers cannot properly activate, leading to muscle weakness. 

The best way to confirm an MG diagnosis is to perform a myasthenia gravis test of the patient’s blood. This MG test will look for the unusual antibodies that are causing the nerve-muscle communication issues. Ulta Lab Tests has MG blood tests available for purchase today. 

The cause and risk factors of MG are not well understood yet. There is no prevention or cure. But, thankfully, most MG patients can be treated with drugs to tackle the antibody problem and regain strength in their muscles. MG will require a lifetime of care, but patients should live long, high-quality lives.

The Basics of Muscle Contraction

At any given moment, your body is executing a huge number of skeletal muscle contractions to perform basic functions like keeping your eyes open or your head upright. Skeletal muscles are semi-autonomic meaning these muscles sometimes perform a voluntary function (e.g. you consciously choose to close your eye), and other times involuntary (e.g. you blink without thinking about it).

Muscle contractions are made possible through nerve signals that communicate to muscle tissue via a chemical neurotransmitter called acetylcholine. The process works like this:

  1. Your body sends a pulse down a nerve until it hits the nerve end. 
  2. Then an acetylcholine neurotransmitter is released, travels through a tiny gap called the synapses, and reaches a muscle fiber. 
  3. The acetylcholine neurotransmitter is captured by an acetylcholine receptor sitting on the muscle fiber. 
  4. The contact between the acetylcholine and a receptor initiates muscle contraction. 

To keep your body functioning, your brain is subconsciously sending a huge number of nerve pulses every second through your body, creating a huge amount of acetylcholine jumping across synapses to reach receptors -- that is unless you have MG. 

What Happens to Muscles in a Myasthenia Gravis (MG) Patient?

For those suffering from MG, their body’s immune system produces an unusual type of protein, called an acetylcholine receptor antibody (AChR), that latches onto the acetylcholine receptors, blocking or destroying the receptors. Without receptors, the nerve cannot tell the muscle fiber to contract. 

When muscles cannot contract all fibers properly, the patient will feel weakness and rapid fatigue in those muscles. The misfiring of nerves could also cause uncontrollable twitching in certain muscles. 

What are the Symptoms of Myasthenia Gravis (MG)?

The general symptom for MG is muscle weakness and fatigue that continues to deteriorate further over time. But MG is called the “snowflake” disease because every patient tends to have their own unique combination of symptoms, with MG impacting different muscles, at different severities, and different onset speeds.

Sometimes MG stays within one muscle group, such as the case with ocular myasthenia gravis in the eyes. Other times, it is considered generalized myasthenia gravis and slowly spreads to other muscle areas.

The most common symptoms include:

  • Eye muscles: In 50%+ of MG patients, a problem with an eye muscle is the first symptom, such as:
  • Drooping of eyelids
  • Double vision
  • Face and throat muscles: The first symptom in about 15% of MG patients 
  • Impaired speaking
  • Difficulty swallowing, increase in choking, liquid coming out of the nose
  • Weakness and fatigue of the jaw muscles when chewing
  • Abnormal smile and facial expressions
  • Neck muscles
  • Difficulty holding up the head
  • Arm and leg muscles
  • Difficulty walking, holding objects

MG patients report sleep temporarily improves their muscle strength, only for the weakness and fatigue to creep back in during the day. 

Patients with MG should not feel any numbness in their body or suffer from any brain/memory issues, which would hint of an alternate explanation like nerve damage or circulatory issues. They should also not be experiencing weakness in involuntary muscles, such as dry mouth, constipation, and impotence as this would hint instead to Lambert-Eaton myasthenic syndrome. 

Any person suffering any of the symptoms of MG needs to take additional steps to confirm if they have the disease.

How is a Myasthenia Gravis (MG) Diagnosis Confirmed?

The primary method of confirming a myasthenia gravis (MG) diagnosis is through a blood test, which seeks to locate the unusual acetylcholine receptor (AChR) antibodies in the bloodstream. Technically, there are three types of AChR antibodies that can be searched for:

  1. The kind of AChR that block receptors (90% of MG patients have these)
  2. The kind of AChR that modulate (alter/weaken) receptors (65% of MG patients have these)
  3. The kind of AChR that bind to receptors (40% of MG patients have these)

Given the “snowflake” nature of this disease, it is hard to guess which type of AChR antibody a person will have, so it is common for blood tests to look for one, two, or all three combinations of the above. 

In rare cases (about 5%), a patient will have seronegative myasthenia gravis, where there are zero antibodies detected and additional types of blood tests will be needed to identify this scenario.

What are the Risk Factors for Myasthenia Gravis (MG)?

Doctors have not found any known risk factors for myasthenia gravis (MG). At this point in our understanding of the disease, MG appears to strike randomly.

In general, the disease affects women more than men, and the peak of symptoms for women occurs before they hit 40 years old, while it peaks in men after they hit 60 years old.

There may be a genetic component that is not understood yet, so individuals with a family history of MG or other autoimmune disorder should carefully monitor themselves for symptoms, and consider proactive blood testing.  

Doctors are also finding that individuals with thyroid problems and autoimmune conditions, such as rheumatoid arthritis or lupus, are more likely to have MG.

What Causes Myasthenia Gravis (MG)?

Doctors are not exactly sure what causes the production of acetylcholine receptor (AChR) antibodies that create the symptoms of myasthenia gravis (MG). 

However, doctors have noticed that 75% of patients suffering from MG are also diagnosed with an enlarged thymus gland, and 10% have malignant (not cancerous) tumors on their thymus. The thymus gland is part of the immune system and sits in the upper chest behind the breastbone. It is believed to play a large role during infancy but gradually becomes less active by adulthood. 

This correlation between MG and an enlarged thymus has led doctors to believe the thymus gland is causing or exacerbating the production of AChR antibodies.

What Happens if Myasthenia Gravis (MG) Goes Untreated?

If left untreated, most generalized MG patients will continue to suffer worse weakening of their skeletal muscles. This will cause continued degradation of quality of life, mobility, and the ability to self-care.

The worst-case result is that MG finally weakens the muscles that allow a person to breathe. This is called a myasthenic crisis and is a life-threatening condition requiring immediate emergency attention.

How is a Myasthenia Gravis (MG) Treated?

There is currently no way to prevent or cure myasthenia gravis (MG). However, the good news is that the symptoms of MG can be controlled, allowing MG patients to live long, high-quality lives. 

The primary methods of treating myasthenia gravis (MG) include:

  • Taking drugs that strengthen the acetylcholine neurotransmitter and receptors
  • Taking drugs that suppress the immune system, in order to suppress the acetylcholine receptor (AChR) antibodies 
  • Removing the thymus gland
  • Having the patient’s blood filtered to clean out the AChR antibodies 

The goal of the above treatments is to reduce the symptoms of MG and regain muscle strength in the skeletal muscles, especially in the muscles important for breathing. Even with treatment, it is still possible for symptoms to go through cycles of flare-ups and temporary remissions. 

Benefits of Using Ulta Lab Tests for Myasthenia Gravis (MG) Testing

The primary method of diagnosing MG myasthenia gravis is through a blood test that detects the unusual acetylcholine receptor (AChR) antibodies in the blood. Ulta Lab Tests has MG blood tests available for purchase today. 

Ulta Lab Tests provide comprehensive and affordable laboratory testing and health screening services directly to consumers. Our mission is to enable individual consumers across America to take control of their healthcare by having direct access to the quality lab tests of their choice. Consumers are now able to be proactive in the early detection and prevention of disease and do so with complete control of their healthcare costs.

Our services are perfect for a wide variety of people, such as:

  • Anyone looking vto proactively monitor their health
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We offer tests that are highly accurate and reliable so you can make informed decisions about your health.

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Order your myasthenia gravis lab test today and your test results will be provided to you securely and confidentially online in 24 to 48 hours for most tests.

Myasthenia gravis (or MG) is a chronic autoimmune disease that negatively impacts skeletal muscle strength by obstructing the communication between muscles and nerves. Typically, MG is first noticed when it brings about weakness in eye muscles and certain symptoms such as double vision and/or drooping eyelid. “Ocular MG” is the collective term for this condition. From the eye muscles, it could spread over time to the neck and facial muscles, causing difficulty chewing and swallowing, slurred speech, and/or difficulty breathing, and weakness from the head and neck to other body parts, which results in generalized MG. Over time, muscle weakness will vary, and it tends to deteriorate with sustained effort but improves with rest.  

All body movements, even those as small as keeping the eyes open and head upright, are usually performed by a coordinated series of muscle contractions. Typically, the initiation of these muscle contractions is done by chemical nerve signals. A nerve impulse travels to a specific nerve ending (on a microscopic level), and a neurotransmitter called acetylcholine is discharged. The chemical travels from that nerve ending to a muscle through a tiny gap found at the “neuromuscular junction.” Then, it adheres to one of many acetylcholine receptors located on the muscle fiber. So, this binding triggers the receptor and causes muscle contraction.  

With myasthenia gravis, the body’s immune system releases proteins (autoantibodies) that target an individual’s acetylcholine receptors and eradicate or block them (acetylcholine receptor antibodies). In turn, this causes the receipt of acetylcholine signals and inhibits weakness and quick muscle fatigue.  

Generally speaking, in the United States, MG is approximated to affect around 5-20 people out of 100,000. Although anyone can develop MG, it is most commonly diagnosed in men aged 60 years and older and also in adult women younger than 40 years old. A woman with MG might pass acetylcholine receptor antibodies to her fetus during pregnancy. This could cause a newborn to experience symptoms of MG; however, the symptoms usually disappear within 2-3 months of birth.  

What Are the Causes of MG? 

It is not known what the cause of MG is; however, approximately 75% of those affected consist of an unusually big thymus gland, and certain people develop thymomas (basically benign tumors of the thymus). Found behind the upper breastbone, the thymus is a relatively small gland. Through young adulthood, it plays a significant role in the immune system but usually starts to shrink after puberty. It is not as active in adults. It’s not fully understood what the relationship between the thymus and MG is. Still, some think that the thymus has an indirect role in activating the production of acetylcholine receptor antibodies.  

Those who have MG are also at an elevated risk of acquiring other autoimmune disorders, including Graves disease, rheumatoid arthritis, or lupus.  

A fraction of those with MG also have an affected family member, but a majority of them do not. The condition known as congenital myasthenic syndrome has symptoms similar to MG, but it is inherited and isn’t an autoimmune disorder. Lambert-Eaton Myasthenic Syndrome is another condition that causes similar symptoms, but it entails an interference with the production of acetylcholine by the nerve ending and not the acetylcholine receptor activity. 

What Are the Symptoms and Signs of MG? 

An individual with myasthenia gravis (MG) might exhibit a wide range of symptoms. These might vary daily, deteriorate after activity and much later in the day; they may improve with rest. MG symptoms might stay confined to the muscles surrounding the eyes – this condition is called ocular MG. In most people, however, the symptoms will extend to the neck, face, and other body parts within about 12 months (generalized MG). In most cases, MG symptoms deteriorate for a few years then stabilize. Some people may have remission over prolonged periods.  

Some of the symptoms might include: 

  • Specific muscle weakness but usual feelings/sensations 
  • Difficulty walking and an altered gait 
  • Trouble holding up the head 
  • Weak neck muscles 
  • Slurred speech 
  • Difficulty chewing, swallowing, with choking, gagging and drooling 
  • Decreased eye movement control 
  • Double vision 
  • Drooping eyelid 

If MG negatively impacts the muscles that control breathing, it could result in a medical emergency known as a myasthenic crisis that usually necessitates hospitalization and might also dictate the temporary use of a respirator to help in ventilation. Illness, stress, heat, and certain medications can result in degrading symptoms. 

Laboratory Tests for MG 

The primary objectives of testing are to diagnose Myasthenia Gravis, differentiate it from other conditions that have similar symptoms, as well as to guide treatment. Also, some tests might be carried out to track an individual’s health status over time.   

In general, laboratory testing might involve measuring one or more autoantibodies:  

  • Anti-MuSK (or muscle-specific kinase) antibodies are found in approximately 50-70% of those who have a negative status for AChR antibodies and also have generalized MG. 
  • AChR (or acetylcholine receptor) antibodies are found in up to 90% of those people with generalized MG and approximately 50% of those with ocular MG.  AChR is MG’s primary blood test. There are three kinds of AChR antibodies: blocking, binding (most frequently tested), and modulating.  
  • Anti-striated muscle antibodies are found in approximately 80% of those people with MG who also have an expanded thymus gland. The presence of these antibodies shows a significantly higher chance of the individual having a thymoma (usually benign tumor in the thymus). 

Some other tests that might sometimes be performed are: 

Non-laboratory tests for MG 

Especially when laboratory test results are inconclusive, one or more of the following evaluations may be performed to help diagnosis. 

  • Acetylcholinesterase test using edrophonium (or tensilon test) involves the intravenous introduction of a drug to determine whether muscle strength improves for a few minutes. 
  • Single-fiber electromyography and/or repetitive nerve stimulation is performed to assess neuromuscular response is a particular area of the body. 
  • Commuted tomography (or CT) of the chest area is used to identify thymoma or an enlarged thymus gland. 
  • An eye orbit or brain MRI (or magnetic resonance imaging) is not performed routinely but could assist in eliminating other causes of eye-related symptoms. 

Treatment for Myasthenia Gravis 

There is no known way to prevent MG or to cure it.  However, MG symptoms may be managed so that most people who are afflicted can lead fairly normal lives.  That being said, if a person’s MG develops a myasthenic crisis affecting their ability to breathe, it must be treated as a medical emergency and often leads to admission to a hospital. 

Managing Myasthenia Gravis 

AchE (or acetylcholine esterase) inhibitors / cholinesterase inhibitors are drugs that will improve nerve and muscle communication and improve muscle strength by increasing the amount of acetylcholine at the neuromuscular junction.  These inhibitors constitute the primary treatment for managing MG. 

A thymectomy (thymus gland removal) may be performed when the patient has a thymoma.  This procedure may reduce a person’s symptoms and, in some instances, resolve them. 

Suppressing a person’s immune response and/or removing or blocking antibodies in the blood are other types of treatments to manage MG. 

Newborns that get MG symptoms from their mother need to be monitored closely for a couple of weeks until the influence of the mother’s antibodies goes away. 

Personal treatment methods and requirements will change over time.  

People with MG need to work with the healthcare provider to stay on top of the right treatments for their changing health status.