A DECIPHER (https://decipher.sanger.ac.uk) [92] search yielded 44 syndromic cases with CNVs involving CDH18 including a case with apraxia, speech and language development, hyperactivity, intellectual disability and a 2.95 Mb duplication partially involving MY010 and CDH18, and a case with attention deficit hyperactivity disorder, speech apraxia, and a 6.96 Mb deletion ranging from DNAH5 to part of CDH18. Speech and language phenotypes were noted in two additional cases with CDH18 CNVs. This evidence concerns the gene POLR3K and attention deficit-hyperactivity disorder.