IQSEC2 and cask-related x-linked intellectual disability: Furthermore, three maternally inherited duplications with disrupted IQSEC2 in five males who presented with ID and behavioral disturbances were reported by Moey et al. (2015), and a de novo deletion of IQSEC2 and the XLID gene KDM5C (MIM*314690; Jensen et al., 2005) has been identified in a girl with severe ID and autistic behavior (Fieremans et al., 2015).