Fig. 1.

a ARMS assay for STAT5B N642H. Heterozygotes have 3 bands—control band (243 bp), wild type (wt) specific band (166 bp) and mutant allele specific band (124 bp). Using serial dilutions of DNA from a mutated case we estimated that the assay can detect STAT5B N642H at a variant allele frequency of 10%. b Summary of mutations for all 27 STAT5B N642H mutated cases as determined by ARMS PCR, Sanger sequencing and myeloid panel analysis. Group 1 are cases with no additional mutated genes, group 2 have additional mutated genes that include SF3B1 and group 3 have additional mutated genes that do not include SF3B1. ARCH = genes strongly associated with age-related clonal hematopoiesis. Full details of additional mutations are given in Supplementary Table 1