SNP Shot: Genomic Insights

Congenital mirror movement disorder is characterized by unintentional, mirrored movements on one side of the body when intentionally moving the other side. For instance, if someone with this condition clenches their right fist, their left hand will mimic that movement. These mirrored movements mainly affect the arms, hands, and fingers. This pattern is present from infancy or early childhood and generally continues throughout life. It doesn't usually present with any other symptoms, and neither intelligence nor lifespan are affected.

Individuals with congenital mirror movement disorder may find some daily tasks challenging, especially those requiring independent hand movements, like typing. They might also experience upper limb pain or discomfort with prolonged hand use.

The severity of these mirror movements varies, even within the same family. Typically, the involuntary movements are visible but less intense than the intentional movements. The degree of mirroring generally remains constant throughout a person's life.

Mirror movements can also occur in individuals without congenital mirror movement disorder. Mild mirror movements are common in young children during normal development and usually disappear before age 7. They can also appear later in life in people with neurodegenerative conditions like Parkinson's disease, or be part of other syndromes with a broader range of symptoms.

Inheritance:

In most cases, including those caused by changes (mutations) in the DCC or RAD51 gene, this condition follows an autosomal dominant inheritance pattern. This means that only one copy of the altered gene in each cell is enough to cause the disorder. Often, an affected person has one parent who carries the altered gene. However, some individuals with the altered gene may not develop the condition, a phenomenon known as reduced penetrance. Research indicates that, in rare cases, the condition might be inherited in an autosomal recessive pattern, where both copies of the gene in each cell must have mutations. In autosomal recessive inheritance, the parents each carry one copy of the mutated gene but usually don't show any signs or symptoms of the condition themselves.