MedGen

Myasthenia gravis (MG) is an autoimmune disease in which antibodies bind to acetylcholine receptors or to functionally related molecules in the postsynaptic membrane at the neuromuscular junction. The antibodies induce weakness of skeletal muscles, which is the sole disease manifestation. The weakness can be generalized or localized, is more proximal than distal, and nearly always includes eye muscles, with diplopia and ptosis. The pattern of involvement is usually symmetric, apart from the eye involvement, which is often markedly asymmetric and involves several eye muscles. The weakness typically increases with exercise and repetitive muscle use (fatigue) and varies over the course of a day and from day to day, often with nearly normal muscle strength in the morning (summary by Gilhus, 2016). [from OMIM]

A type of weakness that occurs after a muscle group is used and lessens if the muscle group has some rest. That is, there is diminution of strength with repetitive muscle actions. [from HPO]

A disorder resulting from loss of function or tissue destruction of an organ or multiple organs, arising from humoral or cellular immune responses of the individual to his own tissue constituents. It may be systemic (e.g., systemic lupus erythematosus), or organ specific, (e.g., thyroiditis). [from NCI]

A morphologic qualifier indicating that a cancerous lesion is well differentiated. [from NCI]

The occurrence of an immune reaction against the organism's own cells or tissues. [from HPO]

A tumor (abnormal growth of tissue) of the thyroid gland. [from HPO]

An inflammatory disorder that affects the thyroid gland. It is characterized by the infiltration of the thyroid parenchyma by lymphocytes. It includes Hashimoto thyroiditis and subacute lymphocytic thyroiditis. [from NCI]

An abnormality of the thyroid gland. [from HPO]

Conditions characterized by impaired transmission of impulses at the neuromuscular junction. This may result from disorders that affect receptor function, pre- or postsynaptic membrane function, or acetylcholinesterase activity. The majority of diseases in this category are associated with autoimmune, toxic, or inherited conditions. [from MONDO]

A group of disorders that affect the neuromuscular system. They may be acquired or inherited and tend to be progressive, resulting in debilitating muscle weakness. [from NCI]

A tumor (abnormal growth of tissue) of the nervous system. [from HPO]

A classification for rare disorders of diverse organ systems (endocrine, neuromuscular, gastrointestinal, renal, dermatologic, rheumatologic, hematologic) that are affected by substances secreted by a distant neoplasm but not by the action of the neoplasm itself metastasizing to that organ or tissue. Less than 1 % of neoplasms are associated with these syndromes. An immune-mediated response to neoplasm-elaborated proteins may be the cause of these syndromes. Additionally, their manifestation may signal the presence of an occult neoplasm, potentially at an earlier stage of disease thereby leading to a better clinical outcome. Constitutional signs may include fever, night sweats, anorexia and cachexia. Clinical course is usually progressive. Prognosis is variable depending on the effective treatment of the underlying neoplasm. [from NCI]

Paraneoplastic neurological syndromes (PNS) can be defined as remote effects of cancer that are not caused by the tumor and its metastasis, or by infection, ischemia or metabolic disruptions. [from ORDO]

A disorder characterized by the degeneration of the nervous system due to autoimmunity. Representative examples include multiple sclerosis, Guillain-Barre syndrome, and myasthenia gravis. [from NCI]

The autoimmune thyroid disorders, or AITDs, comprise 2 related disorders, Graves disease (GD; 275000) and Hashimoto thyroiditis (HT; 140300). See 608173. [from OMIM]