Molecular characteristics

What causes MEF2C haploinsufficiency syndrome?

MEF2C haploinsufficiency syndrome is cause by pathogenic variants (point mutations or deletion) of the MEF2C gene, which is located on chromosome 5 in band 5q14.3 at base pairs 88013975-88199922 [hg19 genome assembly]. One copy of the MEF2C gene does not function normally.

The MEF2C gene function is to control and regulate other genes during the development of the human body. The MEF2C gene plays an important role in the brain development and is also important in the development of the face, skeletal muscle, blood vessel, heart and immune system.

Why did this happen?

When children are conceived the parents’ genetic material is copied in the egg and sperm that make a new child. The biological copying method is not perfect and occasionally random rare variants occur in the genetic code of children that are not seen in the DNA of their parents.

MEF2C haploinsufficiency syndrome occurs when one of these random, rare variants, affect the MEF2C gene. This happens naturally in plants and animals and is not due to your lifestyle or anything you did.

MEF2C pathogenic variants occur out of the blue (de novo). To the best of our knowledge, all the affected people are the first person in their family to have the pathogenic variant in the MEF2C gene.