Clinical features
Disease-causing, DNA changes in one copy of the DCC gene are associated with mirror movements. Individuals with mirror movements have involuntary movements of the opposite limb that mirror the voluntary movements. Some of these individuals may have abnormal findings on brain imaging. This includes absent or incompletely developed corpus callosum, the part of the brain that connects the left and right sides of the brain.
Disease-causing, DNA changes in both copies of the DCC gene are associated with developmental split-brain syndrome, which is characterized by developmental delay, intellectual disability, lack of horizontal movement of the eyes, and progressive scoliosis (or abnormal curvature of the spine). On brain imaging, these individuals are seen to lack nerve cells that connect the left and right sides of the brain (including the corpus callosum).
Prevalence
This is a rare condition and prevalence is largely unknown.
Inheritance
Disease-causing, DNA changes in one copy of the DCC gene can be passed down to the next generation in an autosomal dominant manner from the mother or father. However, not all individuals with the mutation exhibit clinical features (a feature called incomplete penetrance).
When two individuals with disease-causing, DNA changes on one of the gene reproduce, there is a 25% risk for the offspring to inherit both copies with disease-causing variants (referred to as autosomal recessive inheritance), in which case, the offspring will develop developmental split-brain syndrome. There is a 50% chance that the offspring will inherit only one copy of the disease-causing variant (referred to as autosomal dominant inheritance), in which case, they may develop mirror movements and/or abnormality of the corpus callosum.
DCC