Statistical comparison between the four molecular groups, overall and individually, for the six factors of the NH-CSS
| 11p15 ICR1 hypomethylation | mUPD7* | L-SRS-dblneg | UL-SRS* | p Value | |
|---|---|---|---|---|---|
| Mean number of factors positive†,‡ | 5.86 (n=29) | 4.73 (n=11) | 4.42 (n=12) | 2.88 (n=8) | 0.000 |
| SGA (birth weight and/or length)§ | 35 of 35 (100%) | 8 of 11 (72.7%) | 12 of 14 (85.7%) | 7 of 8 (87.5%) | 0.034 |
| Postnatal growth failure§ | 34 of 34 (100%) | 10 of 11 (90.9%) | 11 of 13 (84.6%) | 6 of 8 (75%) | 0.060 |
| Relative macrocephaly at birth§ | 31 of 32 (96.9%) | 9 of 11 (81.8%) | 6 of 13 (46.2%) | 2 of 8 (25%) | 0.000 |
| Protruding forehead§ | 32 of 33 (97.0%) | 11 of 11 (100%) | 12 of 14 (85.7%) | 4 of 8 (50%) | 0.001 |
| Body asymmetry§ | 33 of 35 (94.3%) | 3 of 11 (27.3%) | 8 of 14 (57.1%) | 1 of 8 (12.5%) | 0.000 |
| Feeding difficulties and/or BMI <−2SDS§ | 35 of 35 (100%) | 11 of 11 (100.0%) | 12 of 13 (92.3%) | 3 of 8 (37.5%) | 0.000 |
†One-way ANOVA.
§χ2 test.
*The ‘mUPD7 Unlikely SRS’ subject was removed from this analysis. Even if this subject was included in the ‘Unlikely SRS’ group, the significance level of the overall system remained at 0.000 and the level of significance of the factors remained within their overall significance level categories (<0.001, 0.05 or 0.1).
‡Only subjects with data for all 6 factors were included in this ‘overall’ top-level analysis, to ensure that group mean factor numbers were comparable.
ANOVA, analysis of variance; L-SRS-dblneg, Likely SRS double-negative; mUPD, maternal UPD of chromosome 7; NH-CSS, Netchine-Harbison clinical scoring system; SGA, small for gestational age; SRS, Silver-Russell syndrome; UL-SRS, Unlikely-SRS.