Hereditary diffuse gastric cancer spectrum associated with germline CTNNA1 loss of function revealed by clinical and molecular data from 351 carrier families and over 37 000 non-carrier controls
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By
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May 1, 2026
Objective:
To analyze the clinical and molecular characteristics of CTNNA1 germline variants and their association with hereditary diffuse gastric cancer (HDGC), highlighting the significance of these findings in improving clinical management.
Key Findings:
- CTNNA1-truncating variants are a moderate risk factor for diffuse gastric cancer compared to CDH1 variants, with implications for patient screening.
- CTNNA1-associated disease spectrum includes HDGC and lobular breast cancer, with distinct risks based on variant type, informing clinical decision-making.
- Nonsense-mediated decay (NMD) is the likely mechanism for CTNNA1-related loss of function, providing insights into potential therapeutic targets.
- Clinical criteria for CTNNA1 genetic testing were established, improving identification of at-risk individuals and guiding preventive strategies.
Interpretation:
The study provides a comprehensive understanding of CTNNA1-related hereditary diffuse gastric cancer, clarifying the role of truncating variants and establishing guidelines for genetic testing and clinical management, while acknowledging the limitations of the study.
Limitations:
- The study is retrospective and may be subject to biases in data collection, potentially affecting the reliability of the findings.
- Limited understanding of the full spectrum of CTNNA1 variants due to the rarity of cases, which may restrict the generalizability of the results.
Conclusion:
This research represents the largest dataset on CTNNA1 variants, enhancing the clinical management of carriers and informing variant classification guidelines, with implications for future research directions.
