The condition is caused by a change in the ZNF462gene. This gene helps guide how cells develop in the early embryo, especially cells that go on to form the brain. When one copy of the gene does not work properly, there is not quite enough of its protein (this is called haploinsufficiency), and development is affected in the ways described above.
In most children the gene change is new (it was not inherited from a parent). Occasionally a parent carries the same change, sometimes with only very mild features. Because of this, if a change is found in a child, doctors usually test both parents. If a parent carries the change, there is a 1 in 2 (50%) chance of passing it on in each future pregnancy; families can discuss testing options with their genetics team.
ZNF462