We analyzed 9,672,066 genotyped and imputed germline variants after filtering on control minor allele frequency (>0.5%) and imputation quality score (>0.7; Methods section) and identified six independent genome-wide significant loci (P < 5 × 10−8) (Supplemental Table 2 and Fig. 1), four of which replicated prior MPN findings at 9p24.1 (JAK2), 5p15.33 (TERT), 3q25.33 (IFT80), and 4q24 (TET2)20. This evidence concerns the gene JAK2 and myeloproliferative disorder.