Fig. 4

Global view of the impact of differing models in SVA. PCA performed on the original normalized data (“No SVA”), and on data “cleaned” with SVA using the 3 different models described in the text (a, b and c). Values of individual samples in the first 4 PCs are shown for each analysis, along with a smoothing spline to these PC’s across age (red). SVA Model A: linear spline with a knot at birth [2° of freedom], SVA Model B: 2nd degree basis spline with a knot at birth [3° of freedom], SVA Model C: 2nd degree basis spline with knots at birth, 1, 10, 20 and 50 years [8° of freedom]. Each model also incorporated an offset at birth