5q14.3 deletions including the MEF2C gene have been identified to date using genomic arrays in patients with severe developmental delay or intellectual disability, stereotypic behavior, epilepsy, cerebral malformations and a facial gestalt not really distinctive though characterized by broad and/or high, bulging forehead, upslanting palpebral fissures, flat nasal root and bridge, small, upturned nose, hypotonic small mouth resulting in cupid bow/tented upper lip.
Deletions or intragenic mutations involving the MEF2C gene on chromosome 5q14.3 have generally been associated with a relatively uniform phenotype characterized by severe developmental delay, absent speech, stereotypies, absent or limited gait abilities, lack of a typical facial gestalt and scarcity of major malformations.
Patient 3 had epilepsy, hypotonia, thinning of the corpus callosum, and developmental delay associated with a de novo approximately 2.4 Mb deletion in 5q14.3 including MEF2C and five other genes.