NM_016507.4:c.3424T>A (p.Ser1142Thr) is a missense variant in CDK12 exon 13. This variant is absent from all population databases (gnomAD v2.1, v4.1, gnomAD-Canada), meeting PM2 at moderate strength.1 Multiple lines of computational evidence predict a benign effect: REVEL score 0.142, BayesDel score -0.294, and SpliceAI max delta 0.00, satisfying BP4 at supporting benign strength.2 The variant is absent from ClinVar and COSMIC; no functional data, segregation data, or case-control data are available.3 PVS1 is not applicable as this is a missense variant, not a predicted null variant.4 Overall, one moderate pathogenic criterion (PM2) is met, and one supporting benign criterion (BP4) is met. Per the ACMG/AMP 2015 combination rules, a single moderate criterion with a supporting benign criterion results in a classification of Variant of Uncertain Significance (VUS).5