JOURNAL OF CHILD AND ADOLESCENT PSYCHOPHARMACOLOGY Volume 25, Number x, 2015 a Mary Ann Liebert, Inc. Pp. 1–2 DOI: 10.1089/cap.2015.0107 Letter to the Editor Psychopharmacological Management of Problem Behaviors in Mowat–Wilson Syndrome Aaron D. Besterman, MD, 1 and Robert L. Hendren, DO 1,2 To The Editor: ZEB2 gene, which is predicted to disrupt the canonical splice site between exons 2 and 3. Psychotropic management was initiated by a child neurologist for seizure control and problem behaviors such as irritability, tan- trums, aggression, and nighttime awakenings. In summary, levetir- acetam was found to be helpful for seizure control, but was ultimately discontinued because of worsening aggression and nighttime awak- enings. Ethosuximide, clobazam, and divalproex sodium were also found to be helpful in seizure control, but did not have significant effects on behavior. Risperidone was found to be moderately helpful in reducing the frequency and intensity of tantrums, but overall be- havior remained significantly problematic. Melatonin and clonidine were trialed as sleep aids, without benefit. Amphetamine/dextro- amphetamine salts were trialed for 3 weeks to target attention, but then were stopped because of exacerbation of irritability and tan- trums. At the time of referral for ongoing behavioral management, the patient was on a regimen of risperidone 1.5 mg twice daily, ethosuximide 7 mL b.i.d., and clonidine 0.05 mg at bedtime. On initial presentation, the patient’s father reported that she fre- quently hit caretakers, but would then kiss them ‘‘as if to apologize.’’ She had chronic irritability with sporadic tantrums for up to an hour, with unclear triggers. She awoke several times per night, with in- termittent sleep terrors. We hypothesized that part of her irritability might be the result of difficulty keeping focus on external tasks; therefore, we started dexmethylphenidate 2.5 mg daily. She devel- oped worse aggression and new biting behavior, and was sent home from school for being ‘‘out of control,’’ ultimately leading to a brief hospitalization. We started the patient on olanzapine ODT 2.5 mg at night and divalproex sodium 125 mg b.i.d., up to 250 mg b.i.d, and slowly tapered her off of dexmethylphenidate and risperidone. Im- provements in behavior and sleep were observed; therefore, olan- zapine ODT was gradually increased to 2.5 mg in morning and 10 mg at night. On this new regimen, the patient’s sleep greatly improved with fewer nighttime awakenings, almost-resolved night terrors, improved behavior and learning in school, and less intense and fre- quent tantrums. However, her behavior continued to fluctuate with environmental factors, such as seasonal allergies, and she has gained significant weight since initiating olanzapine ODT. M owat–Wilson Syndrome (MWS) is a neurodevelop- mental disorder characterized by intellectual disability (ID), Hirschsprung disease, agenesis of the corpus collosum, seizures, expressive language deficits, a distinct facial gestalt, congenital heart defects, and behavioral dysregulation, with a happy and social demeanor (Adam et al. 2006). It is caused by de novo heterozygous mutations in the ZEB2 gene, which is produced at high levels in postmitotic neocortical neurons and may play a role in determining neuronal cell fate in corticogenesis (Seuntjens et al. 2009). The be- havioral phenotype associated with MWS was recently characterized in a systematic evaluation of 61 MWS patients (Evans et al. 2012). The MWS behavioral profile was then compared with contrast par- ticipants with ID of various etiologies. Individuals with MWS were found to have higher rates of several behaviors, such as being un- realistically happy or elated and underreacting to pain. However, overall rates of clinically significant psychopathology were similar to the general ID population at *30% (Evans et al. 2012). Evidence-based psychopharmacological approaches can be used to target behavioral and emotional symptoms in individuals with MWS. However, the evidence base is built on studies of individuals with ID of many etiologies (Handen and Gilchrist 2006). Reporting of anecdotal clinical successes and failures in the MWS population specifically is a first step to improving future treatment outcomes. To our knowledge, there are currently no reports in the literature on the psychopharmacological management of problem behaviors in pa- tients with MWS. Therefore, we report our experience with a single patient in hopes that it may act as a starting point toward more precise behavioral management strategies for individuals with MWS. Case Report The patient was a 5-year-old nonverbal girl with ID, seizures, behavioral dysregulation, hypoalgesia, and gastrointestinal motility difficulties. Pregnancy and birth occurred without complication. The patient rolled over at 4 months, walked at 16 months, and babbled at 6 months, but then lost her verbal language abilities until she started babbling again at 4 years of age. Her language com- prehension was intact, but she is learning sign language to ex- press herself. Her developmental course had been complicated by seizures, with early-onset absence seizures and later-onset myo- clonic and atonic seizures. Serial head MRIs revealed trace thin- ning of periatrial white matter without progression. Exome sequencing revealed a c.73 + 1G > T pathogenic variant in the Discussion For many MWS patients with both behavioral problems and seizures, the two can be interrelated, and patients can undergo behavioral decompensation in a post-ictal period or put themselves at increased risk for seizures by becoming agitated and stressed. Department of Psychiatry and 2 Division of Child and Adolescent Psychiatry University of California, San Francisco, California. Funding: This work was supported by the National Institute of Mental Health grant R25MH060482.