Better Delineation of DDX3X Related Phenotype and Epigenetic Signature.

DDX3X related disorder is mainly characterised by developmental delay (DD) and intellectual disability (ID), ranging from mild to severe, and neuroimaging abnormalities. The aims of this study are first to better delineate the clinical phenotype, as well as the neuropsychological profile and, second, to study the epigenetic signature in a cohort of individuals with DDX3X pathogenic variants. This work will conduct to a MD thesis of a clinical resident geneticist in France. Physician that will participate will fill an Excel sheet regarding the clinical and neuropsychological assessment. The investigators will be also happy to have a DNA sample with a minimum 0.5ug of peripheral blood genomic DNA. The investigators will gather the DNA in Montpellier genetic lab (Dr Mouna BARAT) and send the batch to the Dr Sadikovic' lab. Between 2018 and 2020, the investigators have already recruited data from individuals with DDX3X pathogenic variants from several European and Asian genetic centres