GABRB2 and Intellectual disability: Proband 16, a male subject affected by TS, mild intellectual disability, ODD, and MRI abnormalities, had a duplication of about 2.8 Mb of chromosome 5q33.3-q34, involving several genes, including GABRB2 (MIM:600,232), GABRA1 (MIM:137,160), and GABRG2 (MIM:137,164).