ARID1B-related disorder in 87 adults: Natural history and self-sustainability

Purpose: ARID1B is one of the most frequently mutated genes in intellectual disability cohorts. Thus, far few adult-aged patients with ARID1B-related disorder have been described, which limits our understanding of the disease’s natural history and our ability to counsel patients and their families. Methods: Data on patients aged 18+ years with ARID1B-related disorder were collected through an online questionnaire completed by clinicians and parents. Results: Eighty-seven adult patients with ARID1B were included. Cognitive functioning ranged from borderline to severe intellectual disability. Patients identified through the genetic workup of their child were either mosaic or had a variant in exon 1. New clinical features identified in this population are loss of skill (16/64, 25%) and recurrent patella luxation (12/45, 32%). Self-sustainability data showed that 88% (45/51) could eat independently, and 16% (7/45) could travel alone by public transport. Facial photo analysis showed that patients’ photographs taken at different ages clustered consistently, separate from matched controls. Conclusion: The ARID1B spectrum is broad, and as patients age, there is a significant shift in the medical aspects requiring attention. To address the changing medical needs with increasing age, we have formulated recommendations to promote timely intervention in an attempt to mitigate disease progression.