Similarly, a non-dysmorphic patient with intellectual disability, autism and West syndrome was found to have a de novo p.Gly70Asp mutation in TBL1XR1.28 Three patients, including a mother and child, have been described with a deletion involving only TBL1XR1 in patients who had mild to moderate intellectual disability without autistic behaviour or manifestations of Pierpont syndrome.29, 30 In addition, three cases with small deletions involving TBL1XR1 and other genes are included in the Decipher database (http://decipher.sanger.ac.uk/). This evidence concerns the gene TBL1XR1 and Pierpont syndrome.