Extended Data Fig. 4: Correlation between chromosome length and estimates of variance explained from linkage analyses of BMI.

Analyses were based on summary statistics from a linkage meta-analysis of BMI and BMI adjusted for polygenic score (PGS). The x axis represents the physical length of each chromosome relative to the size of the autosome (that is, ~2879 Mb). The y axis represents the expected variance explained (\({q}_{{\rm{s}}}^{2}\)) for each chromosome (s = 1–22) estimated as \({q}_{{\rm{s}}}^{2}=\,{m}_{s}{\bar{q}}^{2}\), where \({\bar{q}}^{2}\) is the mean across the chromosome of estimates of locus-specific variance, and m_s an effective number of independent markers per chromosome (Supplementary Table 8). Error bars around each dot represent m_s times the standard deviation of linkage estimate across the chromosomes. Standard errors (s.e.) of the regression slopes were obtained using a leave-one-chromosome-out jackknife approach. 95% confidence intervals (CI) were calculated as 1.96×s.e.