The ATM c.8362C>T (p.His2788Tyr) variant has not been observed in somatic cancers in COSMIC and has been reported in ClinVar as uncertain significance by 2 clinical laboratories.¹ This variant is absent from gnomAD v2.1 and gnomAD v4.1, and the observed population frequency is therefore below the ATM PM2_Supporting threshold of <=0.001%.² A multiplex functional study classified p.His2788Tyr as non-functional with high confidence, but the available data are based on olaparib fitness assays and do not yet establish the ATM-specific rescue framework required to apply ATM PS3 or BS3 without manual review.³ REVEL is 0.669, which is below the ATM PP3 threshold of >0.7333 and above the ATM BP4 missense threshold of <=0.249, while SpliceAI predicts no significant splice effect with a maximum delta score of 0.01, below the benign splicing threshold of <=0.1.⁴