This missense variant (NM_001184.3:c.1316A>G, p.Asn439Ser) in ATR is absent from all population databases including gnomAD v2.1, v4.1, and gnomAD-Canada v1.0, consistent with PM2 at supporting level.¹ Multiple in silico tools predict a benign effect: REVEL score of 0.042, BayesDel score of -0.769573, and SpliceAI max delta of 0.02 (no predicted splice alteration), consistent with BP4 at supporting benign level.² The variant is absent from ClinVar with no prior classifications, no COSMIC entries, no hotspot association, and no variant-specific functional data in OncoKB or the literature. No variant-specific publications were identified.³ PVS1 is not applicable as this is a missense variant; it does not fall into the null-variant buckets defined by the ClinGen SVI PVS1 framework.⁴ Overall, one supporting criterion toward pathogenicity (PM2) and one supporting benign criterion (BP4) are met. This does not satisfy the combination thresholds for Likely Pathogenic (≥2 supporting) or Likely Benign (≥2 supporting benign) under the generic ACMG/AMP 2015 classification rules. The variant is classified as a Variant of Uncertain Significance (VUS).⁵