The DCC gene provides instructions for making a protein called the netrin-1 receptor, which is involved in the development of the nervous system. Mutations in other genes that have not been identified likely account for other cases of this disorder. Mirror movements may also be present in certain other conditions with a wider range of signs and symptoms (syndromes).Ĭongenital mirror movement disorder can be caused by mutations in the DCC or RAD51 gene mutations in these genes account for a total of about 35 percent of cases.

They can also develop later in life in people with neurodegenerative disorders such as Parkinson disease.

Mild mirror movements are common during the normal development of young children and typically disappear before age 7. Mirror movements can also occur in people who do not have congenital mirror movement disorder. The extent of the movements typically stay the same throughout the lifetime of an affected individual. In most cases, the involuntary movements are noticeable but less pronounced than the corresponding voluntary movements. The extent of the mirror movements in this disorder can vary, even within the same family. They may experience discomfort or pain in the upper limbs during prolonged use of the hands. People with congenital mirror movement disorder can have some difficulty with certain activities of daily living, particularly with those requiring different movements in each hand, such as typing on a keyboard. Intelligence and lifespan are not affected. This pattern of movements is present from infancy or early childhood and usually persists throughout life, without other associated signs and symptoms. The mirror movements in this disorder primarily involve the upper limbs, especially the hands and fingers. For example, when an affected individual makes a fist with the right hand, the left hand makes a similar movement. Congenital mirror movement disorder is a condition in which intentional movements of one side of the body are mirrored by involuntary movements of the other side.

Looking in a hand mirror