The syndrome is caused by a genetic change involving the MYT1L gene, which is located on chromosome 2. These genetic changes include deletions of the whole gene or sections of the gene, as well as mutations that cause the gene not to be made into a protein (‘loss of function’ mutations), or change the ‘spelling’ of the gene (‘missense mutations’) and affect the gene function.
Almost all known aberrations (both deletions and mutations) arose de novo, meaning that they are absent in the parents, but present in all cells of the child. In case the genetic change is not found in the parents, brothers or sisters without any signs of the disorder do not need to be tested.
Large deletions in MYTL can be identified by genomic microarrays.
Mutations in MYTL can be identified using targeted or genome-wide sequencing technology..