Successful use of clozapine in a patient with schizophrenia comorbid with 22q11.2 deletion syndrome and multiple periventricular nodular heterotopia: A case report

Background 22q11.2 deletion syndrome is associated with schizophrenia, seizures, and often experience intolerance to antipsychotics. Periventricular nodular heterotopia (PNH) is a neuronal migration disorder that can also be observed in individuals with 22q11.2 deletion syndrome. However, to our knowledge, the use of clozapine in adolescent patients with treatment‐resistant schizophrenia and comorbid 22q11.2 deletion syndrome and PNH has not been previously reported. Case Presentation A 17‐year‐old female with treatment‐resistant schizophrenia was referred to our hospital. She presented with auditory hallucinations, disorganized behavior, and insomnia. Multiple antipsychotics, mood stabilizers, benzodiazepines, and modified electroconvulsive therapy were either ineffective or poorly tolerated due to extrapyramidal symptoms. Brain magnetic resonance imaging (MRI) performed under sedation revealed PNH. Genetic testing confirmed a diagnosis of 22q11.2 deletion syndrome. Clozapine was initiated with close monitoring, and her symptoms gradually improved following a slow titration. She was discharged after approximately 6 months and has remained clinically stable for 15 months. Conclusion Brain MRI and genetic testing—even when performed under sedation—may be valuable diagnostic tools in adolescents with treatment‐resistant schizophrenia. Furthermore, the presence of structural brain abnormalities does not preclude the efficacy of clozapine, which may remain a viable and effective treatment option in such cases.