NM_033360.4:c.407G>A (p.Ser136Asn) is a missense variant in KRAS, a RASopathy gene. The variant is present in population databases (gnomAD v2.1: 3/251,172 alleles, AF=0.00119%; gnomAD v4.1: 11/1,613,106 alleles, AF=0.00068%), precluding application of PM2 (VCEP requires complete absence).¹ The variant is located at codon 136, outside the VCEP-approved PM1 functional domains (P-loop residues 10-17, Switch I residues 25-40).² No pathogenic variants have been established at this residue in KRAS, HRAS, or NRAS, precluding PM5 application.³ No de novo occurrences, segregation data, case-control studies, or functional characterization are available for this variant. PP2 is met at supporting strength per VCEP specification, as KRAS is a RASopathy gene where missense variants are a common disease mechanism with a low rate of benign missense variation.⁴ BP4 is met at supporting strength: multiple lines of computational evidence suggest no impact on the gene product (SpliceAI max delta 0.01, BayesDel -0.256, REVEL 0.274).⁵ ClinVar classifies this variant as Uncertain Significance (4 clinical laboratories) and Likely Benign (1 clinical laboratory).⁶