The RUNX1 c.319_323del (p.Ala107GlnfsTer2; p.A107Qfs*2) variant has been reported in ClinVar and classified as Pathogenic by the ClinGen Myeloid Malignancy Variant Curation Expert Panel.¹ This variant is absent from gnomAD v2.1 and gnomAD v4.1, which is below the RUNX1 PM2_Supporting threshold of <=0.00005 and far below the BS1 and BA1 population thresholds.² This 5-bp deletion causes an early frameshift with a premature stop codon, and the exact expert-panel ClinVar record states that the default RUNX1 transcript consequence p.Ala134fs is predicted to undergo nonsense-mediated decay, supporting PVS1; the same record also applied RUNX1-specific PM5_Supporting because the frameshift is downstream of c.98.³ SpliceAI predicts no significant splice impact for this variant (max delta score 0.03), which is below the RUNX1 PP3 threshold of 0.38 and consistent with the <=0.20 splice caveat used for PM5_Supporting.⁴