Partial MEF2C deletion in a Cypriot patient with severe intellectual disability and a jugular fossa malformation: review of the literature.

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. We report on a patient of Cypriot descent with a de novo, approximately 147 kb in size, partial MEF2C deletion removing exons 1 to 3. He had a history of severe intellectual disability with absent speech, poor eye contact, hand stereotypies and a wide-based gait. A broad-based, shallow jugular pit with an overlying vascular malformation was also present. Partial MEF2C deletions have only been reported in a very small number of patients and have on occasion been associated with relatively milder phenotypes. We present a patient of Cypriot descent with such a deletion and review previously published literature on partial MEF2C gene deletions postulating a key role of the first few exons in the pathogenesis of the disease.