For example, deletion of 1.6 Mb (175 507 453–177 095 072) in the 3q26.31q26.32 region, or a 1.3 Mb deletion in the 3q26.32(176 025 379-177 377 006) region that includes TBL1XR1 gene, causes intellectual deficiency (85, 86). This evidence concerns the gene TBL1XR1 and Intellectual disability.