Home > Encyclopedia of Neurological Disorders > Congenital Myasthenia

Definition Congenital myasthenia is an inherited condition present at birth that interferes with nerve messages to the muscles. Although some symptoms are similar (muscle weakness worsened by use), congenital myasthenia differs from myasthenia gravis, which usually presents in adulthood and is almost always due to an autoimmune disorder rather than an inherited genetic defect.

Description

Most cases of congenital myasthenia are noticeable at or shortly after birth. In rare cases, symptoms don't present themselves until some time later in childhood or in early adult life.

Normal muscle function requires a chemical messenger called acetylcholine (ACh) to travel from the nerve cell to a receptor on the muscle endplate, in order to stimulate muscle contraction and movement. After the ACh has initiated muscle contraction, it is...