[Hereditary diffuse gastric cancer (HDGC): presentation of a family with a new mutation of the CDH1 gene].

HDGC is a hereditary cancer syndrome with an autosomic dominant pattern. It may be clinically diagnosed by family background, and confirmed by genetic testing. In 40% of the families, a mutation in the CDH1 gene (E-cadherin) can be identified. Furthermore, the identification of the pathogenic mutation enables the segregate non-carriers (having population risk) and carriers. Prevention for the latter group includes prophylactic gastrectomy or surveillance endoscopy every 6 to 12 months.to present the case of an HDGC family with identified CDH1 mutation.28 year-old woman who underwent gastrectomy for a diffuse type gastric cancer. Her family background showed multiple gastric cancers with inherited autosomal-dominant pattern (affectation of 9 members in 5 generations). Suspecting HDGC, a plan of surveillance endoscopy was iniciated, and a her DNA sample was sequenced for CDH1 gene finding a non-sense mutation in position 1913 G>A (W638X) of exon 12.the detailed recollection of the family background allowed to identify a rare inherited entity. The molecular testing confirmed the diagnosis and will allow future tailored counselling among relatives.