Genetic syndromes are prevalent in patients with comorbid neurodevelopmental disorders and catatonia.

Catatonia occurs at high rates in idiopathic and syndromic neurodevelopmental disorders. At our institution's multidisciplinary catatonia clinic, clinical genetic testing (including microarray, fragile X PCR and methylation, autism/ID expanded panels, and exome sequencing) was commonly completed as part of clinical workup on patients with co-occurring neurodevelopmental disorders and catatonia (performed in 36/48 cases or 75%). This testing identified a pathogenic or likely pathogenic finding in 15/36 patients (42%). Testing identified a VUS (variant of uncertain significance) in 9/36 patients (25%). On review of the VUS findings, 4/9 were felt to be suspicious and potentially diagnostic. Testing was negative for 12/36 patients (33%). Many of the variants identified in this cohort were found in genes involved in gamma aminobutyric acid (GABA) and glutamatergic synaptic signaling; imbalances of these neurotransmitters are hypothesized to be drivers of catatonia. More work is needed to further characterize the molecular underpinnings of catatonia in the setting of neurodevelopmental disorders, including expanding genetic testing to larger cohorts in the future.