Next, we estimated the GRM from the SNPs on each autosome and partitioned the total genetic variance onto individual chromosomes by fitting the GRMs of all the chromosomes simultaneously in a joint analysis (Online Methods). We observed a strong linear relationship between the estimate of variance explained by each chromosome ( hC2) and chromosome length (LC, in Mb units) for height (P = 1.4×10−6 and R2 = 0.695) and QTi (P = 1.1×10−3 and R2 = 0.422) (Fig. 1 and Supplementary Tables 2 and 3). We mapped SNPs to 17,787 genes according to positions on the UCSC Genome Browser hg18 assembly (http://genome.ucsc.edu)20, 17,652 of which had at least one SNP within ± 50 Kb of the 5′ and 3′ untranslated regions (UTRs). There was also a significant correlation between the estimate of hC2 and the number of genes on each chromosome (Ng(C)) for height and QTi (Supplementary Table 3). Since LC and Ng(C) are correlated (r = 0.628), we performed a multiple regression analysis of the estimate of hC2 on LC and Ng(C), and fitted models in which chromosome length
