Fig. 2

Coefficient of variation (CV) for chromosome 21 with and without adaptive sample selection using the representative sample with a GC = 0.424. The baseline bar represents the coefficient of variation used to measure the genomic representation of chromosome 21 among reference samples (n = 396) without adaptive sample selection. Additional bars represent the CV with adaptive sample selection. The bar marked A represents the coefficient of variation used to measure the genomic representation of chromosome 21 among selected reference samples (n = 37). The B (n = 210), C (n = 120), D (n = 166), E (n = 226), and F (n = 278) also represent the CV with various numbers of reference samples