Psychiatric Phenotype Characterization of Individuals With FOXP1 Syndrome

FOXP1 syndrome is a rare genetic disorder with a variable phenotype, characterized somatically by facial dysmorphia, dysphagia, hypotonia, relative or real macrocephaly, which may be associated with cerebral, cardiac, urogenital and ocular malformations. Psychiatrically, the syndrome manifests as a global developmental delay, then as mild to severe intellectual development disorder, speech and language impairments, behavioral issues that may include autistic features, hyperactivity and emotional lability. Assessing a cohort of 17 patients with FOXP1 syndrome, Trelles et al (2021) reported a significant frequency of autistic spectrum disorders, attention deficit/hyperactivity disorder (ADHD), and anxiety disorders. They also noted the presence of repetitive behaviors in the majority of patients and sensory-seeking behaviors. However, within the patient population at the Child and Adolescent Psychiatry Department of Necker Enfants Malades Hospital, a significant prevalence of psychotic disorders was observed. Additionally, families reported ineffectiveness and poor tolerance of methylphenidate in these patients. Therefore, it appears crucial to further characterize the psychiatric phenotype of individuals with FOXP1 syndrome and explore the link between agitation and psychotic prodromes.