Here we have a unique and quite rare disorder. The Congenital Mirror Movement Disorder is a serious condition in which intentional movement by one side of the body is involuntarily copied or mirrored by the other side. For example, when people with the condition make a fist with one hand, the other hand automatically does the same without the individual being able to control it.
Mirror hand syndrome is the most common as this disorder causes issues with the upper limbs very commonly. The hands and fingers are severely affected by the disorder. A pattern of movements is seen developing during early childhood, and it persists through the rest of the individual’s life. However, it is a myth that the mirror hand syndrome affects one’s intelligence or lifespan in any way.
The cause of this disorder has been attributed to genes inherited from family members. Mutations in genes like the DDC or RAD51 are what lead to this extremely rare condition. There is an impairment in or missing netrin-1 receptor protein, which occurs as a result of the mutations. With a lack of protein, there is an impaired growth of axons when the nervous system is developing. This eventually leads to abnormal functioning of the brain and the mirror hand syndrome.
While there are 1 in a million cases of this disorder in the world, it is inherited in what is known as the autosomal dominant pattern. In layman’s terms, this means that either of the parents might have altered genes leading to the syndrome in the child. There have been cases reported where it has been passed on in the autosomal recessive pattern as well, wherein both parents carry a copy of the mutated gene.
People with mirror hand syndrome have difficulty conducting certain daily life functions, especially those requiring the hands. This includes typing on the keyboard. Individuals with the condition also experience acute pain in the hands after using them for a long time.
The nature and extent of the condition tend to vary from person to person. At times the voluntary movement is noticeable, but the involuntary mirror movement is not. However, the extent of the condition remains the same throughout one’s lifetime.
Another interesting fact is that children often exhibit mirror movements until the age of seven, even if they do not have mirror hand syndrome. For several others, the condition develops as a result of neurodegenerative disorders like Parkinson’s disease.
What are some other names of CMM?
CMM or congenital mirror movement disorder has also been called by other names by medical professionals and people alike. Some of these are:
● Congenital mirror movements
● Mirror hand syndrome
● Mirror movements
● Bimanual synergia
● Bimanual synkinesis
Frequently Asked Questions
- How is congenital mirror movement disorder diagnosed?
There are mainly two ways in which CMM is diagnosed. One is through clinical findings like observations of signs and symbols of the condition during early infancy. Another way is through molecular genetic testing.
- Is there a permanent cure for CMM?
Unfortunately, no. The condition is not connected to any neurological disorder, and it is extremely rare. In most cases, the effects are minimal. Hence, no permanent cure has been found yet.
Congenital mirror movement disorder or mirror hand syndrome is not something to be worried about. Even though it stays throughout an individual’s lifetime, it does not impact everyday functioning to a great extent. People suffering from it eventually get accustomed to the issue and adapt accordingly.
Jay Johannigman was a resident surgeon for 25 years with the University of Cincinnati Medical Center and served as the Director of trauma.