Myasthenia gravis (MG) is a disorder that causes weakness in muscles around the body. This happens because antibodies destroy some of the places where nerves and muscles meet (neuromuscular connections). MG affects the voluntary muscles of the body. It mostly affects the eyes, mouth, throat, arms, and legs. It most often affects adults, but can sometimes happen in children.
There are 3 types of MG in children:
This is a temporary form of MG. It can happen in babies born to mothers with MG. It occurs when antibodies from MG cross over to the baby growing in the mother’s uterus. Transient neonatal MG usually lasts only a short time. The symptoms go away weeks or months after birth, as the antibodies are naturally replaced. Babies are not at greater risk of developing MG later in life.
This is an autoimmune disorder. It most often occurs in white teen girls. It is a lifelong condition that may go in and out of remission. About 1 in 10% cases of MG in children are juvenile MG. Treatment is often done by removing the entire thymus gland. This may cure the disorder.
This is a very rare form of MG. It is not an autoimmune disorder. It is inherited as an autosomal recessive disease. This means that both boys and girls are equally affected. It also means that 2 copies of the gene, 1 inherited from each parent, are needed to have the condition. There are about 12 rare genetic disorders that may cause congenital MG. Symptoms of congenital MG usually start at birth and are lifelong. Some forms may be treated with the same medicines that are used for adults.
Myasthenia gravis is not contagious. This means it can’t be spread from person to person. It may be acquired through immune proteins or antibodies to babies born to mothers with MG. Or the disorder may develop by chance later in childhood. Rare forms of MG are caused by gene changes.
A child is more at risk for myasthenia gravis if he or she has a mother with MG, or parents with certain gene changes.
Symptoms can occur a bit differently in each child, and vary by type of MG. They can include:
Babies may be weak and have poor sucking. They may have breathing problems. In some cases, a baby’s respiratory muscles are so weak the baby can’t breathe on his or her own. Then the baby may need the help of a mechanical breathing machine (ventilator). Symptoms go away as the mother’s antibodies disappear over time.
Symptoms may start slowly over weeks or months. A child may become very tired after very little activity. He or she may start to have trouble with chewing and swallowing. Drooping eyelids may be so severe that the child can’t see. The symptoms tend to be milder in the morning and worse later in the day.
The symptoms are usually noted at birth, but may begin in the first year. They include overall weakness in the arms and legs. Babies may have delays in motor skills such as crawling, sitting, and walking. They may have trouble feeding or breathing. And they may have weak eyelids and poor head control.
The symptoms of myasthenia gravis can be like other health conditions. Make sure your child sees his or her healthcare provider for a diagnosis.
The healthcare provider will ask about your child’s symptoms and health history. He or she may also ask about your family’s health history. He or she will give your child a physical exam. Your child may also have tests, such as:
Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is, and the type of MG.
Transient neonatal MG goes away on its own in weeks or months. There is no cure for juvenile or congenital MG, but the symptoms may be controlled. It is usually a lifelong condition.
A child may need:
Treatment may also include any of these:
Talk with your child’s healthcare providers about the risks, benefits, and possible side effects of all treatments.
In severe cases, a child may need a breathing machine (ventilator) to help with breathing.
Talk with your healthcare provider if you are pregnant and have MG. Your healthcare provider may advise genetic counseling. You can learn more about the risk of MG in a future pregnancy.
Issues can revealed as a child grows and develops. Children with myasthenia gravis need to see their healthcare team often.
You can help your child strengthen his or her self-confidence and be as independent as possible. The healthcare team will talk with you about the best ways to help your child.
Call the healthcare provider if your child has:
Tips to help you get the most from a visit to your child’s healthcare provider:
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