Sandhoff Disease Associated With Bipolar Disorder: A Case Report From the United Arab Emirates.

Late‑onset Sandhoff disease is a rare lysosomal storage disorder that may present with neuropsychiatric features. This report describes a 38-year-old woman with an established diagnosis of bipolar I disorder who developed progressive neurological symptoms alongside an acute manic and psychotic episode. Her presentation included motor incoordination, speech difficulties, weakness, and functional decline, accompanied by cerebellar signs on neurological examination and structural changes on neuroimaging. Genetic evaluation confirmed a pathogenic variant consistent with Sandhoff disease. The acute psychiatric episode was managed with antipsychotic and mood‑stabilizing treatment, leading to resolution of manic symptoms and subsequent psychiatric stability during rehabilitation and follow‑up. This case highlights the importance of considering an underlying metabolic or neurogenetic disorder when psychiatric symptoms occur in the context of progressive neurological findings, as such comorbidity can complicate diagnosis and management and requires a multidisciplinary approach.