The -472delA (rs5030625) and -160C>A (rs16260) polymorphisms in CDH1 induce a decrease in gene transcription; in fact, these mutated alleles have been associated with GC in some populations, with conflicting results.
Gastric cancer (GC) is considered to be one of the leading cancers in East Asians, and mutations in the CDH1 gene and the reduced expression of E-cadherin are the most frequent genetic alterations in gastric cancer.
Analysis of HDGC patients harbouring CDH1 alleles with PTCs at a wide variety of different positions indicates an association of their predicted ability to induce NMD and an earlier age of onset of gastric cancer.
In our area, in which a high rate of familial aggregation was demonstrated, the lack of germ line mutation of TP53 together with the infrequency of mutation of E-cadherin gene seem to limit the role of genetic predisposition in the development of gastric cancer.
Using polymerase chain reaction (PCR)/single-strand conformation polymorphism (SSCP)/sequencing, we screened 32 Portuguese families with a history of gastric cancer and 23 patients with early onset gastric cancer for CDH1 germline mutations.
Overall, 78% of GC cases harbored one clinically relevant GA or more, with the most frequent alterations being found in TP53 (50%), ARID1A (24%), KRAS (16%), CDH1 (15%), CDKN2A (14%), CCND1 (9.5%), ERBB2 (8.5%), PIK3CA (8.6%), MLL2 (6.9%), FGFR2 (6.0%), and MET (6.0%).
This case highlights the importance of recognition of the HDGC syndrome and of testing for CDH1 germline mutations in young individuals with diffuse gastric cancer without a family history of the disease.