The RUNX1 c.617dup (p.His206GlnfsTer7; p.H206Qfs*7) variant has not been reported in ClinVar, and OncoKB lists p.H206Qfs*7 as Likely Oncogenic with a likely loss-of-function effect.¹ This variant is absent from gnomAD v2.1 and gnomAD v4.1, which supports rarity in the general population and is below the RUNX1 PM2_supporting threshold of 0.00005.² This variant is a truncating frameshift, and the RUNX1 MM-VCEP framework recognizes loss of function as an established disease mechanism for RUNX1; the available PVS1 assessment supports full-strength PVS1 for this variant.³ SpliceAI predicts no significant splice effect, with a maximum delta score of 0.02, which is below the 0.20 threshold and is consistent with the RUNX1 PM5_supporting rule for downstream nonsense or frameshift variants.⁴