Summary of molecular testing. (A) Comparison of molecular testing performed before and after 1 July 2021. Patients were counted both before and after 1 July 2021 if high sensitivity PCR testing was performed in both. For PB testing, 4 patients had PCR testing both before and after 1 July 2021. Of those with PB PCR testing, 159 had 1 test and 15 had 2 or more PCR tests during either the before and/or after 1 July 2021 time points. For BM testing, 2 patients had PCR testing both before and after 1July 2021. Of those with BM PCR testing, 71 had 1 testing method and 10 had 2 or more testing methods performed (See supplemental Methods). (B) Distribution of tryptase genotypes in both the total cohort excluding patients with SM and in the subgroup of patients with SM. Four patients in the total cohort excluding patients with SM were tryptase genotyped before 1 July 2021 and 1 patient in the SM subgroup was tryptase genotyped before 1 July 2021. (C) Comparison of KIT p.D816V positive results by testing modalities performed before and after 1 July 2021. Fifty-nine patients had only 1 positive testing method and 20 patients had 2 or more positive testing methods by either PB and/or BM during either before and/or after 1 July 2021 time points.