NM_000249.3:c.551C>G (p.Ser184Ter) is a nonsense variant that introduces a premature termination codon at codon 184 of MLH1, well before the VCEP threshold of codon 753, meeting PVS1_VeryStrong.¹ The variant is absent from gnomAD v2.1, v4.1, and gnomAD-Canada population databases, meeting PM2_Supporting under the InSiGHT VCEP threshold of <0.00002 allele frequency.² ClinVar reports this variant as Pathogenic with 3 clinical laboratory submissions, classified as criteria provided, single submitter. However, under the InSiGHT VCEP, PP5 and BP6 are not applicable, and ClinVar classification alone does not independently satisfy other criteria.³ No variant-specific functional studies, patient phenotype data, co-segregation data, or de novo observations were identified in the available literature or case materials.