Lujan-Fryns Syndrome (LFS) is a developmental disorder of genetic origin that usually presents with neuropsychiatric symptoms such as autism, intellectual disability, aggression, and psychosis. Its heterogeneity poses a challenge for diagnosis and psychopharmacological treatment approaches. A 19-year-old male from Pucallpa, of Jewish descent, leptosomic, with no reported family history, presented marfanoid features, psychotic symptoms. He experienced psychosis, social withdrawal, obsessive thoughts, and uncontrollable impulses. After ruling out similar pathologies, he was diagnosed with LFS. He received a treatment regimen consisting of clozapine, periciazine, carbamazepine, clomipramine, and levomepromazine, achieving partial remission of psychotic and obsessive symptoms. The etiology of LFS is linked to genetic mutations, such as those affecting the MED12 gene. Diagnosis is based on th...