The MEF2A gene encodes a member of the myocyte enhancer factor 2 (MEF2) family of transcription factors, that is conserved from yeast to humans.  The encoded protein is required at different stages of the life cycle, and is expressed at high levels in cardiac, skeletal, neuronal cells, smooth muscles, and in the endothelium of coronary arteries.  It is necessary for post-natal function, and activates many muscle-specific, growth factor-induced, and stress-induced genes.  It also plays important roles in several cellular processes, including cell growth control, neuronal differentiation, apoptosis, and muscle development. Within the last decade, a 21-bp deletion in exon 11 of this gene was reported as a causative mutation in a single large family with Autosomal Dominant Coronary Artery Disease.  Later, more variants in this gene were discovered in families with CAD.  

The MEF2A gene, located at chromosome 15q26.3, consists of nine coding exons spanning approximately 115 kb in the genomic DNA.  The gene is transcribed in a wide range of cell types, and has alternative mRNA splicing variants that give rise to muscle-specific isoforms.  The N termini of MEF2 proteins contain highly conserved MADS and MEF2 domains, which together mediates protein dimerization and binding to AT-rich DNA sequences.  The C terminus function as a transcriptional activation domain, has complex patterns of alternative splicing, and also has a role in nuclear localization. The genomic sequence of MEF2A gene is highly polymorphic, with exon 11 being the most polymorphic.  Exon 11 harbours several substitutions as well as indels.