What are the genetic changes related to idiopathic inflammatory myopathy ?
Idiopathic inflammatory myopathy is thought to arise from a combination of genetic and environmental factors. The term "idiopathic" indicates that the specific cause of the disorder is unknown.  Researchers have identified variations in several genes that may influence the risk of developing idiopathic inflammatory myopathy. The most commonly associated genes belong to a family of genes called the human leukocyte antigen (HLA) complex. The HLA complex helps the immune system distinguish the body's own proteins from proteins made by foreign invaders (such as viruses and bacteria). Each HLA gene has many different normal variations, allowing each person's immune system to react to a wide range of foreign proteins. Specific variations of several HLA genes seem to affect the risk of developing idiopathic inflammatory myopathy. Researchers are studying variations in other genes related to the body's immune function to understand how they contribute to the risk of developing idiopathic inflammatory myopathy.  It is likely that specific genetic variations increase a person's risk of developing idiopathic inflammatory myopathy, and then exposure to certain environmental factors triggers the disorder. Infection, exposure to certain medications, and exposure to ultraviolet light (such as sunlight) have been identified as possible environmental triggers, but most risk factors for this condition remain unknown.