MECP2 and Pelizeaus-Merzbacher spectrum disorder: To our knowledge, several disorders have been proved to be non-recurrent events occurred via NHEJ, FoSTeS or MMBIR, including Miller-Dieker lissencephaly syndrome37, 17p13.3 duplication syndrome38, Pelizaeus-Merzbacher disease (PMD)39 and MECP2 duplication syndrome40.