This variant resides at codon 12 within the P-loop domain (AA 10-17), a critical functional domain per RASopathy VCEP specifications. Codon 12 is a well-established mutational hotspot with no benign variation. The variant lies in a statistically significant hotspot.¹ The variant is absent from gnomAD v2.1, v4.1, and gnomAD-Canada, supporting rarity in the general population.² The variant is an in-frame deletion-insertion that alters protein length (p.Gly12delinsCysAla) in a non-repetitive region, consistent with a potential gain-of-function effect in the RAS/MAPK pathway.³ No variant-specific functional studies, de novo observations, case reports, or segregation data were identified in the available literature or databases. OncoKB classifies this variant as Oncogenic with gain-of-function effect.⁴ Insufficient evidence exists to reach a definitive classification under the RASopathy VCEP v2.3.0 framework. Met criteria: PM1 (Moderate), PM2 (Supporting), PM4 (Moderate). Key data gaps include absence of functional studies, patient phenotype data, and segregation analysis.⁵