Molecular Investigation, Using Chromosomal Microarray and Whole Exome Sequencing, of Patients Affected by Williams Beuren Syndrome and Autism Spectrum Disorder

Williams Beuren syndrome (WBS) is a multiple malformations/intellectual disability (ID) syndrome caused by 7q11.23 microdeletion and clinically characterized by a typical neurocognitive profile including excessive talkativeness and social disinhibition, often defined as "overfriendliness" and "hypersociability". WBS is generally considered as the polar opposite phenotype to Autism Spectrum Disorder (ASD). Surprisingly, the prevalence of ASD has been reported to be significantly higher in WBS (12%) than in general population (1%). This study aims to investigate the molecular basis of the peculiar association of ASD and WBS. The investigator performed chromosomal microarray analysis and whole exome sequencing in six patients presenting with WBS and ASD, in order to evaluate the possible presence of chromosomal or gene variants considered as pathogenic.