MRI results: phenotypic males. Group mean (SD) regional brain volumes in ml are given for information. Proportions of regional to whole brain volume were used for statistical analysis
| XYY | XXY (Klinefelter) | XY | ANOVA | Post hoc Scheffe test | |
|---|---|---|---|---|---|
| Number scanned | 10 | 10 | 25 | ||
| Whole brain | 1383.3 (99.6) | 1296.1 (87.8) | 1438.0 (85.3) | F2,42=9.2, p=0.0005 | p⩽0.05 (XY>XXY) |
| Right prefrontal lobe | 79.4 (10.5) | 76.5 (7.8) | 83.9 (11.3) | F2,42=0.2, p=0.8 | |
| Left prefrontal lobe | 72.0 (6.9) | 73.5 (7.8) | 77.8 (11.0) | F2,42=1.7, p=0.2 | |
| Right temporal lobe | 85.3 (9.1) | 78.5 (6.5) | 91.2 (5.4) | F2,42=3.5, p=0.04 | No significant differences |
| Left temporal lobe | 81.4 (6.5) | 74.8 (5.6) | 85.2 (6.7) | F2,42=0.7, p=0.5 | |
| Right caudate nucleus | 4.2 (0.6) | 4.1 (0.4) | 4.5 (0.5) | F2,42=0.5, p=0.6 | |
| Left caudate nucleus | 4.3 (0.6) | 4.1 (0.5) | 4.7 (0.5) | F2,42=1.0, p=0.4 | |
| Right lentiform nucleus | 4.7 (0.4) | 4.5 (0.3) | 5.3 (0.5) | F2,42=1.5, p=0.2 | |
| Left lentiform nucleus | 4.9 (0.7) | 4.5 (0.4) | 5.3 (0.5) | F2,42=0.5, p=0.6 | |
| Right thalamic nuclei | 6.0 (0.6) | 5.7 (0.5) | 6.2 (0.8) | F2,42=0.1, p=0.9 | |
| Left thalamic nuclei | 6.5 (0.6) | 6.2 (0.6) | 7.0 (0.5) | F2,42=0.5, p=0.6 | |
| Right amygdalohippocampal complex | 4.9 (0.5) | 4.4 (0.4) | 5.0 (0.4) | F2,42=0.9, p=0.4 | |
| Left amygdalohippocampal complex | 4.5 (0.5) | 4.1 (0.3) | 4.5 (0.4) | F2,42=0.4, p=0.7 | |
| Right lateral ventricle | 4.6 (2.4) | 8.1 (5.6) | 3.6 (2.3) | F2,42=8.1, p=0.001 | P⩽0.05 (XXY>XYY, XY) |
| Left lateral ventricle | 5.9 (3.2) | 7.4 (3.5) | 4.3 (2.9) | F2,42=5.8, p=0.006 | p⩽0.05 (XXY>XY) |
| Third ventricle | 0.4 (0.2) | 0.5 (0.3) | 0.5 (0.3) | F2,42=0.9, p=0.4 | |
| Fourth ventricle | 1.0 (0.3) | 1.1 (0.6) | 1.0 (0.5) | F2,42=0.8, p=0.5 |