Whereas, for the CACNA2D1 variants, epilepsy, autism, attention deficit hyperactive disorder, ataxia, facial dysmorphism, clinodactyly, brachymetacarpy, abnormal skin, short stature, transient diabetes with hyperinsulinemia, hearing impairment, aggressiveness, agitation, stereotypic hand movements, primary aldosteronism, heart defects and hypotonia can be seen in additional to ID/GDD. This evidence concerns the gene CACNA2D1 and Hearing impairment.