NM_033360.3:c.35_37delinsATT (p.Gly12_Gly13delinsAspCys) is an in-frame deletion-insertion in exon 2 of KRAS, altering codons 12 and 13 within the P-loop domain (AA 10-17), a critical functional domain per the ClinGen RASopathy Expert Panel specifications v2.3.0.¹ The variant is absent from gnomAD population databases (v2.1, v4.1, and Canada), meeting PM2 at supporting strength per the RASopathy VCEP.² The variant lies within the P-loop domain (AA 10-17), a well-established functional domain, and the residue is a statistically significant hotspot, meeting PM1 at moderate strength.³ As an in-frame deletion-insertion in a non-repeat region, the variant meets PM4 at moderate strength per the RASopathy VCEP.⁴ No variant-specific functional studies, de novo observations, segregation data, or proband reports are available. The variant is absent from ClinVar and COSMIC.⁵ The combined evidence (PM1 moderate, PM4 moderate, PM2 supporting) yields 2 moderate and 1 supporting pathogenic criteria, which does not meet any RASopathy VCEP combination rule for Pathogenic or Likely Pathogenic. No benign criteria are met. The variant is classified as a Variant of Uncertain Significance (VUS) under the ClinGen RASopathy Expert Panel specifications for KRAS v2.3.0.⁶