NM_000535.7:c.33T>C (p.Pro11=) is a synonymous variant in exon 2 of PMS2. It is absent from gnomAD v4.1, meeting PM2_Supporting under the InSiGHT VCEP v2.0.0 framework (allele frequency < 0.00002).¹ SpliceAI predicts no splicing impact for this synonymous variant (max delta score = 0.00, ≤ 0.1), meeting BP4_Supporting under the InSiGHT VCEP v2.0.0 framework.² ClinVar records this variant as Likely benign (4 submissions from clinical laboratories; ClinVar Variation ID 525878), though the review status is criteria provided, single submitter and this alone does not constitute an independent ACMG criterion under the VCEP framework.³ No functional studies, segregation data, tumor phenotype data, or variant-specific literature were identified for NM_000535.7:c.33T>C. Multiple criteria (PS3, BS3, PP1, PP4, BS4, BP5) could not be assessed due to absence of evidence. Applying the InSiGHT MMR VCEP v2.0.0 combination rules: PM2_Supporting (pathogenic supporting) and BP4_Supporting (benign supporting) are both met. With one pathogenic supporting and one benign supporting criterion and no criteria at higher strength levels, the combination rules do not yield a definitive classification. This results in a classification of Uncertain Significance.⁴