The Phelan–McDermid syndrome is a chromosomal disorder consisting of a selection on chromosome 22q13.3 associated psychiatric and emotional level, behavioral and traits of autism spectrum disorders. During the neurodevelopmental such chromosomal deletion, which associated with haplo insufficiency Shank 3 causes alterations in the synaptogenesis altering the balance of activating and inhibitory transmission. Throughout the various studies, it is considered that this syndrome has a psychiatric disorder bipolar like.

Here, we present s 13-year-old female diagnosed with autism spectrum disorders in childhood and presented regression with catatonia features and behavioral disorders. Interestingly, she presented mutation/microdeletion of the SHANK3 gene, inducing a premature stop codon in exon 21. Different pharmacological treatments (antipsychotics at high doses and benzodiazepines) failed to improve clinical symptoms and lead to multiple adverse events. In contrast, lithium therapy reversed clinical regression, stabilized behavioral symptoms and allowed patients to recover their pre-catatonia level of functioning. After the first menstruation there was a cycling psychiatric worsening with a similar clinical pattern so risperidone as adjunctive therapy. As a result of this, this patient recovered clinical and socio-functional stability.

They are previous cases where there affective and behavioral improvement after use of mood stabilizer molecules such as valproate or lithium. There is also evidence of the benefit of risperidone low to have a beneficial effect on the balance of activatory and inhibitory transmission level doses of NMDA receptors.

The authors have not supplied their declaration of competing interest.