CONCLUSION: The cognitive profile of DIJOS is more variable than suggested by existing literature, with only 1 of 4 family members meeting DSM-5-TR criteria for IDD. Recognizing the clinical heterogeneity of DIJOS may aid in earlier detection and provision of more individualized supports. Future longitudinal studies will be important for examining the role of genetic as opposed to environmental contributors to clinical presentation and characterizing symptom trajectory across the lifespan.
