EXOG – Pseudomyxoma Peritonei

In a recent familial study of appendiceal mucinous tumours presenting with pseudomyxoma peritonei (PMID:32357859), a heterozygous missense variant in EXOG (c.178G>A (p.Ala60Thr)) was identified in a father‐daughter pair. This finding represents the only available genetic evidence linking EXOG to pseudomyxoma peritonei, as the variant was observed in both affected individuals with minimal segregation data; one affected relative (the non‐index family member) provided limited supportive evidence. Additionally, loss‐of-heterozygosity analysis in the tumour tissue from the father did not reveal somatic loss of the wild type allele, further underscoring the candidate nature of this association. The genetic evidence is therefore restricted to a single familial instance without independent replication across unrelated probands or robust segregation metrics.

Functional assessment studies for EXOG in this context have not provided clear insights into a pathogenic mechanism. Without compelling experimental data—such as animal or cellular model validation, expression studies, or rescue experiments—the functional evidence remains limited. In summary, while the identification of the EXOG missense variant offers a potential diagnostic marker in familial pseudomyxoma peritonei, the current evidence is not sufficient for definitive clinical implementation and calls for further investigation. Key take‑home: The EXOG variant may serve as an early indicator for predisposition in familial pseudomyxoma peritonei cases, but additional genetic and functional studies are needed to firmly integrate this finding into clinical practice.

References

• BMC Cancer • 2020 • Germline whole exome sequencing of a family with appendiceal mucinous tumours presenting with pseudomyxoma peritonei PMID:32357859

Evidence Based Scoring (AI generated)