YY1 Related Disorder : Clinical Phenotype, Neuropsychological Profile, Brain MRI Characteristics and Epigenetic Signatures.

YY1 related disorder, also known as Gabriele-de-Vries syndrome, 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 the brain MRI characteristics; and, second, to study the epigenetic signatures in a cohort of individuals with YY1 intragenic 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 either CD-ROM or a link to have access to the brain MRI data as well as 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 2019 and 2020, the investigators have already recruited data from individuals with YY1 pathogenic variants from several European and American genetic centres.