Molecular and cytomorphologic diagnosis in patients with VEXAS syndrome. (A) The Sanger sequencing chromatograms for the UBA1 (NM_0033334) mutations: c.121 A>G, p.Met41Val (n = 2); c.121 A>C, p.Met41Leu (n = 1); c.122 T>C, p.Met41Thr (n = 1). (B) Characteristic vacuoles in erythroid and granulocytic precursor cells in BM from all UBA1-mutated patients (May-Grümwald-Giemsa stain). (C) Variant allele frequencies (VAFs) for putative somatic variants identified by high-throughput sequencing. Because of their location on the X chromosome, VAFs for UBA1 (black boxes) and ZRSR2 are divided by 2 to allow their representation on the same graph. UPN, unit patient number.