The top mutant genes and their pooled mutation rates were as follows: <i>SF3B1</i> (20.2% [95% CI 11.6-30.5%]) in MDS, <i>TET2</i> (39.2% [95% CI 21.7-52.0%]) in MDS/MPN, and <i>JAK2</i> (67.9% [95% CI 64.1-71.6%]) in MPN. This evidence concerns the gene JAK2 and myeloproliferative disorder.