Myocyte enhancer factor 2C (MEF2C) haploinsufficiency syndrome (MCHS) has been attributed to 5q14.3 microdeletions (MIM# 613443, developmental delay, stereotypic movements, epilepsy and/or cerebral malformations) (1) and was defined as any microdeletions of chromosome 5q14.3-5q15 that involved multiple genes (www.omim.org). Here, MEF2C is linked to Down syndrome.