G73: Disorders of myoneural junction and muscle in diseases classified elsewhere

The group of conditions referred to as "Disorders of myoneural junction and muscle in diseases classified elsewhere" generally involve abnormalities at the junction where nerve impulses are transmitted to muscles (the myoneural or neuromuscular junction) or directly within the muscle tissue itself. These disorders can be secondary manifestations of other diseases, which means they occur as a result of another, primary health condition. Symptoms typically include muscle weakness, fatigue, and sometimes muscle atrophy or muscle wasting. These symptoms can worsen gradually, may vary widely among patients, and can involve any voluntary muscles, impacting multiple bodily systems. The causes of these disorders are diverse and can include genetic conditions, autoimmune disorders, or infections, among others, depending on the primary disease. The progression of these disorders also varies depending on the underlying disease.