While generalized myasthenia gravis (gMG) is not hereditary, genetics may be involved. People are more likely to develop gMG if they have a family history of any autoimmune condition.
Generalized myasthenia gravis (gMG) is a chronic autoimmune disease that disrupts communication between nerve cells and muscles, causing muscle weakness.
Exactly why someone develops gMG isn’t clear, but the condition may involve a combination of factors, including genetics.
Read on to learn about whether gMG is hereditary, along with risk factors and triggers for the condition.
No, gMG is not considered to be hereditary. In fact, it’s rare for more than one family member to have gMG.
However, gMG is an autoimmune disease, and it’s not unusual for several family members to have an autoimmune condition, even if they don’t all have the same condition. So genetics may be involved in the development of gMG. Researchers have been looking into whether there may be higher rates of this condition within families.
A 2020 study that included more than 1,000 people with a specific type of gMG living in North America found that the rate of gMG within families was higher than what would be expected of a random disease. Researchers also noted that a disproportionate number of people with the condition had a personal or family history of autoimmune disease.
These findings suggest that genetics may play some role in the development of gMG. However, gMG is a rare condition in general; therefore, even if a family member is more likely to develop the condition than in the random population, the overall risk and incidence in family members are still very low.
There is a temporary form of myasthenia gravis that mothers can pass on to their newborns. It’s called transient neonatal myasthenia gravis because it lasts just a few days to a few weeks.
Another condition called congenital myasthenia syndrome exists as well. However, this is an inherited genetic disorder, not an autoimmune condition.
Like other autoimmune disorders, gMG happens when the immune system mistakenly attacks healthy parts of the body. In gMG, this involves the creation of antibodies that interfere with signals between nerve cells and muscles.
What sets all this in motion isn’t clear. As with other autoimmune conditions, it may be a combination of a genetic predisposition (a tendency to have a certain type of condition) and one or more environmental triggers.
It may also be related to thymus gland abnormalities, which occur in about 75% of people who live with gMG, according to the National Organization for Rare Disorders. The thymus gland is part of your immune system.
Certain triggers can worsen gMG symptoms, including:
- lack of sleep
- fatigue
- overexertion
- stress
- anxiety
- depression
- pain
- illness or infection
- extreme temperatures and humidity
- bright lights and sunlight
- alcohol
- quinine (often found in tonic water)
- low potassium
- abnormal thyroid levels
- exposure to certain chemicals
Certain medications and supplements can also trigger symptoms. These may include:
- antibiotics (such as ciprofloxacin)
- beta-blockers
- Botox
- calcium channel blockers
- lithium
- magnesium
- muscle relaxants
Medications to treat gMG can help reduce symptoms and possibly put the disease into remission. Connect with a doctor if your symptoms are worsening to try to narrow down the cause and explore treatment options.
Anyone can develop gMG. The average age at which people notice symptoms of the disorder is 28 years for women and 42 years for men, per the Genetic and Rare Diseases Information Center. People also tend to develop gMG after having an infection or illness.
No racial or ethnic groups appear to be at higher risk of gMG, and the disease is not contagious.
You may be at a higher risk of gMG if:
- You have another autoimmune disease.
- You have family members with autoimmune diseases.
- You have an abnormality of the thymus gland.
With treatment, most people with gMG have an average outlook, with no drops in life expectancy. Even though there’s no cure for the disease yet, it can be managed quite effectively. Treatments can help minimize symptoms.
You may find that you have periods of increased symptoms followed by times of remission when symptoms are significantly reduced or go away completely. The course of the disease is different for everybody, so there’s no way to know whether you’ll have a remission or how long it may last.
Some people with gMG have surgery known as a thymectomy to remove the thymus gland.
About half of them experience long-term remission, according to the
Treatment for gMG may include medication, surgery, and other therapies.
Your doctor will recommend specific treatments depending on a variety of factors, including:
- the severity of your symptoms
- your age
- your overall health
Treatment options for gMG include:
- anticholinesterase medications
- immunosuppressive drugs
- monoclonal antibody treatment
- intravenous immunoglobulin therapy (IVIG)
- plasma exchange (plasmapheresis)
- thymectomy
Self-care can also be an important part of reducing gMG symptoms. For example, symptoms tend to get worse when you’re tired, so it’s important to listen to your body and pace yourself throughout the day.
Here are some other ways to manage gMG:
- giving yourself time for a full night’s sleep
- resting your eyes and taking naps as needed
- getting physical activity when your energy levels are high
- incorporating nutritious foods into your diet
- avoiding extreme temperatures
- learning some relaxation techniques, such as meditation, to curb stress
- seeing your doctor regularly and taking medication as prescribed
Does myasthenia gravis run in the family?
No, it’s rare for more than one family member to have gMG.
Who is most likely to get myasthenia gravis?
Anyone can develop gMG. But people with another autoimmune disease, family members who have an autoimmune disease, or a condition affecting their thymus gland are more likely to develop gMG.
What causes myasthenia gravis to start?
No one knows exactly what triggers gMG, but it may be a combination of genetics and environmental exposure or problems with the thymus gland.
What is the life expectancy of someone with myasthenia gravis?
Treatment for gMG is generally very effective, and people with this disease may have no reduction in their life expectancy.
While gMG is not a hereditary disease, a genetic component may be involved in the development of the condition. Autoimmune disorders can run in families. So your risk of developing gMG may be a bit higher if you or others in your family have another autoimmune condition.
The condition can happen to anyone at any time, though it’s more likely to occur after an infection or illness.
People with gMG typically have a positive outlook, with no changes in life expectancy or levels of independence. Treatments, including medication and surgery, can minimize symptoms and potentially put gMG into remission.
Talk with a doctor about which treatment options might be right for you.