Mutations of the MEF2C gene [OMIM # 600662] have been identified in patients with severe mental retardation, stereotypic movements, hypotonia, and epilepsy. Patients can also present with facial dysmorphic features and cerebral malformations. Brain imaging is typically abnormal, including nonspecific anomalies of the corpus callosum, enlarged ventricles, periventricular white matter hyperintensities and cortical atrophy. Phenotypic overlap exists between patients with MEF2C mutations and atypical Rett syndrome. Zweier, et al, 2010 detected four de novo mutations in MEF2C in 362 patients with severe mental retardation of unknown etiology. Gross deletions of 5q14.3 including partial and whole deletions of MEF2C have also been reported.
MEF2C sequencing is available as an individual test, or as part of our Rett/Atypical Rett syndrome panel and Comprehensive Non-Syndromic Intellectual Disability panel. Please see our information sheets for more details.