Myasthenia gravis

Myasthenia gravis (MG, Latin: "grave muscle weakness") is a neuromuscular disease leading to fluctuating weakness and fatiguability. It is one of the best known autoimmune disorders and the antigens and disease mechanisms have well been identified. Weakness is caused by circulating antibodies that block acetylcholine receptors at the post-synaptic neuromuscular junction, inhibiting the stimulative effect of the neurotransmitter acetylcholine. Myasthenia is treated with immunosuppression and cholinesterase inhibitors.

Epidemiology

Myasthenia gravis occurs in all ethnic groups and both genders. It most commonly affects young adult women (under 40) and older people of both sexes (over 60), but it can occur at any age.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

In neonatal myasthenia, the fetus may acquire immune proteins (antibodies) from a mother affected with myasthenia gravis. Generally, cases of neonatal myasthenia gravis are transient (temporary) and the child's symptoms usually disappear within few weeks after birth. Other children develop myasthenia gravis indistinguishable from adults.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Myasthenia gravis is not directly inherited nor is it contagious. Occasionally, the disease may occur in more than one member of the same family. Rarely, children may show signs of congenital myasthenia or congenital myasthenic syndrome. These are not autoimmune disorders, but are caused by defective genes that control proteins in the acetylcholine receptor or in acetylcholinesterase.

Related Topics:
Acetylcholine receptor - Acetylcholinesterase

~ ~ ~ ~ ~ ~ ~ ~ ~ ~