Catatonia associated with mosaic 18q deletion syndrome: a case report

Background Catatonia is increasingly diagnosed in neurodevelopmental disorders, yet most data focus on individuals with autism spectrum disorder. To our knowledge, catatonia has not been reported in association with chromosome 18 deletion syndrome. Case presentation We describe a 19-year-old woman with a mosaic terminal 18q deletion (18q23) who developed severe catatonia following SARS-CoV-2 infection. She presented with mutism, stupor, negativism, posturing, rigidity, waxy flexibility, and withdrawal. Extensive neurological, infectious, and autoimmune workup, including cerebrospinal fluid analyses, revealed no abnormalities. Electroencephalography (EEG) showed intermittent frontotemporal right-dominant dysfunction, characterized by short clusters of high-amplitude polymorphic theta paroxysms without epileptiform discharges. Symptomatic treatment with lorazepam led to rapid initiation of speech within 24 h and full remission of catatonic features after four days. Follow-up EEG recordings at three and ten months were normal, and no recurrence occurred. Conclusions This first reported case raises the possibility that individuals with the rare chromosome 18q deletion, including mosaic forms, may be vulnerable to catatonia particularly in the presence of systemic or environmental stressors such as viral infection or environmental change. Awareness of this potential association and early benzodiazepine treatment are critical to prevent complications and facilitate recovery.