TBL1XR1 and Intellectual disability: In one additional published patient the phenotype was attributed to a 2.2 Mb deletion at 3q26.3 involving TBL1XR1, but an updated annotation showed that the deletion did not encompass TBL1XR1.31 This suggests that the phenotype of individuals with a microdeletion 3q26.3 is caused by a loss of function of TBL1XR1, and consists of intellectual disability and frequently ASD, and a phenotype that shows no resemblance to Pierpont syndrome.