The manifestation of this condition, also known as MN1 C-terminal truncation (MCTT) syndrome or CEBALID (Craniofacial deformities, dysmorphic Ears, Brain Abnormalities, Language delay, and Intellectual Disability), results from the dominantly active truncated protein of MN1 rather than haploinsufficiency [9]. The gene discussed is MN1; the disease is Intellectual disability.