Social attention is a key aspect of neurodevelopment and is significantly altered in neurodevelopmental genetic syndromes and many individuals with idiopathic autism spectrum disorder (ASD). The primary aim of the present study was to examine the psychometric properties of webcam-collected social attention measurements, including four new specific aspects of social attention, in three genetic syndromes (PTEN Hamartoma Tumor Syndrome-PHTS
Malan Syndrome-NFIX
and SYNGAP1-related disorder-SYNGAP1), a mixed group of other neurodevelopmental genetic syndromes (Other NDGS), and individuals with a range of idiopathic neurodevelopmental disorder (NDD). The secondary aim was to evaluate the construct validity of these social attention measurements, including evaluating known-groups validity across study groups and concurrent validity for separating ASD and non-ASD cases. Participants (N = 467, age 3-45
PHTS n = 102, NFIX n = 23, SYNGAP1 n = 42, other NDGS n = 63, idiopathic NDD n = 53, neurotypical siblings n = 71, and unrelated neurotypical controls n = 113) completed a 4-min online-administered social attention paradigm that includes a variety of distinct stimuli at three timepoints (baseline, 1-month, and 4-month follow-up). Social attention measures had good scale and test-retest reliability, with the exception of measures of non-social preference and face-specific processing. Unique patterns of social attention emerged across study groups, with near neurotypical levels in PHTS and weaker social attention in NFIX and SYNGAP1 relative to controls. Global social attention had good accuracy in detecting ASD within NDGS participants. Remote monitoring social attention, including distinct aspects of social attention, may be useful for characterizing phenotypic profiles and tracking the natural history of distinct NDGS and idiopathic NDD as well as identifying ASD within NDGS. Given their reproducibility and stability, global social attention and several distinct social attention measures may be useful outcomes for future clinical trials.