Germline MLH1 c.-42 C > T is a likely pathogenic variant predisposing to a reduced-penetrance/modified Lynch syndrome phenotype featuring MLH1-methylated cancers

Key Points

• Individuals with the MLH1 c.-42 C>T variant may have a higher risk of developing MLH1-methylated cancers.
• The study highlights the reduced penetrance associated with this pathogenic variant, indicating not all carriers show symptoms.
• Applying genetic testing for MLH1 variants can enhance cancer risk assessment among at-risk individuals.
• Further studies are needed to confirm the association between this variant and its actual cancer risks and implications.