– The MeCP2 helps regulate gene activity (expression) by modifying chromatin, the complex of DNA and protein that packages DNA into chromosomes. The MeCP2 protein is present in cells throughout the body, although it is particularly abundant in brain cells.In the brain, the MeCP2 protein likely plays a role in maintaining connections (synapses) between neurons, where cell-to-cell communication occurs. The alternative splicing of proteins is critical for normal communication between neurons and may also be necessary for the function of other types of brain cells.