Potential Association of the CSMD1 Gene with Moderate Intellectual Disability, Anxiety Disorder, and Obsessive-Compulsive Personality Traits

CSMD1 is a gene involved in various biological processes and is highly expressed in the central nervous system, where it plays a key role in complement activity, brain circuit development, and cognitive function. It has been implicated as a susceptibility gene for schizophrenia and a causative factor in developmental epileptic encephalopathy, neurodevelopmental disorders, and intellectual disability. However, no MIM phenotype number has been assigned to CSMD1 for a specific disorder. Here, we report an individual presenting with moderate intellectual disability, anxiety disorder, obsessive–compulsive personality traits, and facial dysmorphisms. Trio-based whole-exome sequencing (WES) identified two heterozygous CSMD1 variants, c.8095A>G and c.5315T>C, both classified as variants of uncertain significance (VUS) according to ACMG criteria. Computational analysis using the DOMINO tool supported an autosomal recessive inheritance model for CSMD1. This study contributes to the growing evidence linking CSMD1 to neurodevelopmental phenotypes, highlighting the need for further investigations to clarify its pathogenic role.