Question: What is (are) Congenital mirror movement disorder ?
Answer: Congenital mirror movement disorder (CMM) is a rare condition that is characterized by mirror movements (involuntary movements of one side of the body that mirror intentional movements on the opposite side). Affected people generally develop these movements in infancy or early childhood, which usually persist throughout their life without any related signs or symptoms. In most cases, the involuntary movements are noticeable but less pronounced than the corresponding voluntary movements; however, the severity of symptoms can vary significantly, even among family members. CMM can be caused by changes (mutations) in the DCC or RAD51 genes and inherited in an autosomal dominant manner. In some families, the exact underlying cause of CMM is unknown.
Source: GARD