Remote Language Assessment in School‐Age Children With Phelan– <scp>McDermid</scp> Syndrome and Genotype–Phenotype Correlation

People with Phelan-McDermid syndrome (PMS) have reduced speech and language abilities, yet little research has profiled the communication abilities in this population. The purpose of this study was threefold: identifying the language and communication profiles of school-aged children with PMS, identifying genetic contributions to language and communication abilities, and determining the feasibility of remote data collection for research purposes. A speech language pathologist used standardized assessments and direct evaluations by video conferencing to evaluate language and communication abilities. Sixteen children and adolescents were evaluated: 5 with SHANK3 pathogenic variants, 9 with 22q13 deletions including SHANK3 (PMS-SHANK3 related), and 2 with 22q13 deletions preserving SHANK3 (PMS-SHANK3 unrelated). All showed moderate-to-severe language impairment across all assessments. Females demonstrated higher communication abilities than males. Haploinsufficiency of SHANK3 appears to be the main driver of language impairment in PMS; however, participants with preserved SHANK3 also scored in the impairment range, suggesting other contributions from 22q13 genes to the language phenotype. This study demonstrates the efficacy of using standardized instruments and remote data collection methods to assess communication in PMS. Remote methods may be helpful for the assessment of other genetic disorders involving language phenotypes.