Table 2. Characteristics of the IQ reported studies.
| Author | Year | Diagnostic criteria | Perform | FSIQ |
VIQ |
PIQ |
|||
|---|---|---|---|---|---|---|---|---|---|
| DEL (M, SD) | UPD (M, SD) | DEL (M, SD) | UPD (M, SD) | DEL (M, SD) | UPD (M, SD) | ||||
| Dykens et al. | 2008 | K-BIT2 | NA | 62.07, 12.3 (n=55) | 64.96, 13.07 (n=33) | - | - | - | - |
| Soni et al. | 2008 | Wechsler | carry out by the first author | 64.5,8.5 (n=24) | 68.7,11.2 (n=22) | - | - | - | - |
| Zarcone et al. | 2007 | Wechsler | Trained research staff conducted IQ test | 62.3, 55.1 (n=41) | 65.2, 12.1 (n=30) | 63.3, 9.3 (n=41) | 71.3, 11.9 (n=30) | 65.7, 9.3 (n=41) | 63.1, 11.3 (n=30) |
| Descheemaeker et al. | 2006 | NA | NA | 57.2, 16.21 (n=40) | 58.4, 15.56 (n=18) | - | - | - | - |
| Milner et al. | 2005 | Wechsler and Raven’s | the researchers involved were blind to the genetic status of participants. | 70.78, 16.21 (n=45) | 69.49, 16.89 (n=47) | 81.16, 17.4 (n=19) | 79.62, 21.08 (n=21) | 76.53, 14.43 (n=19) | 68.57, 10.44 (n=21) |
| Walley et al. | 2005 | Wechsler | NA | - | - | 71.64, 12.08 (n=12) | 76.50, 8.64 (n=6) | - | - |
| Bulter et al. | 2004 | Wechsler | NA | - | - | 62.52, 9.18 (n=25) | 70, 6.20 (n=21) | - | - |
| Boer et al. | 2002 | NA | NA | 67.0, 12.39 (n=9) | 62.4, 9.86 (n=5) | - | - | - | - |
| Fox et al. | 2001 | NA | NA | 62.7, 9.8 (n=24) | 63.9, 6.4 (n=19) | 62.1, 9.5 (n=24) | 69.7, 5.5 (n=19) | 66.5, 9.6 (n=24) | 61.6, 7.7 (n=19) |
| Roof et al. | 2000 | Wechsler | carry on by a licensed psychological examiner | 61, 9.2 (n=24) | 64.1, 7.9 (n=14) | 60.8, 8.6 (n=24) | 69.9, 6.4 (n=14) | 64.7, 9.3 (n=24) | 62.2, 9.7 (n=14) |
| Dykens et al. | 1999 | Kaufman or Wechsler | two of the university clinics | 62.97, 8.83 (n=23) | 70.93, 11.15 (n=23) | - | - | - | - |
NA: not available