The syndrome is caused by a change, also called mutation, in the FAM111B gene, which is the genetic information to build the FAM111B protein. The function of the FAM111B protein is still unknown, but studies are ongoing to determine it.
As described in three family case reports, mutations were found in the children and were absent in both parents. They are therefore considered as de novo. In such case, the risk is very low for future children to have the same FAM111B mutation and be affected by the same disorder as the older brother or sister. This risk is however increased compared to that of the general population.
Each child of an affected individual has a 50% chance of being affected dependent on whether or not he or she inherits the mutated or normal copy of the gene from the affected parent.
Prenatal genetic counselling can be offered in families where the diagnosis has been molecularly confirmed.