Main clinical features

A number of genetic changes involving the MYT1L gene (see Molecular Characteristics) have been described to lead to a complex neurodevelopmental disorder characterized by intellectual disability, severe speech and motor delay, and mild dysmorphic facial features. Common health problems are brain abnormalities, hyperphagia, obesity and behavioral problems such as autistic features and aggressiveness towards others.


Thus far, approximately 35 patients have been described with deletions or mutations affecting the MYT1L gene, making it a rare condition.


Most of these aberrations occur spontaneously in the child (“de novo”), meaning that none of the parents carries the genetic change. It is therefore unlikely, but not impossible, that multiple patients are present in a single family.