Mapping the Genotype, Phenotype, and Natural History of Phelan-McDermid Syndrome

The purpose of this study is to comprehensively characterize PMS using standardized medical, cognitive, and behavioral measures and to track the natural history of the syndrome using repeated longitudinal assessments. In addition, this study will be aiming to identify biomarkers using neuroimaging, including diffusion tensor imaging and identify genetic factors which contribute to diverse phenotypes in patients with PMS.

Phelan-McDermid syndrome (PMS) or 22q13 Deletion syndrome, caused by a loss of one copy of the SHANK3 gene, is characterized by global developmental delay/intellectual disability, motor skills deficits, delayed or absent speech, and autism spectrum disorder. The goal of this study is to understand more about the PMS phenotype and the biological pathways associated with ID and ASD in the disorder, and to establish the foundation for future clinical trials in PMS and in other ID/ASD-associated disorders that share signaling pathways with PMS. Individuals with PMS will be asked to participate in this study if they are 18 months or older with pathogenic deletions or mutations of the SHANK3 gene at time of enrollment, as well as healthy controls. Both males and females will be asked to participate. Additionally, to be eligible for study participation, individuals' primary communicative language must be English. Parents and unaffected siblings may also be asked to consent to have blood drawn for analysis. The study involves 3 on site visits over 2 years. Study visits involve a physical exam, medical history questions, blood work and neuropsychological assessments. A subset of participants between the ages of 2 and 11 years old will take part in the EEG portion of the study. Individuals who have a clinically indicated MRI will have an option to provide routine clinical scans for analysis.