PURPOSE: The objective of this study was to determine the male and female frequency of diffuse gastric cancer (DGC), the age at diagnosis, and the country of origin in a selected population with germline CDH1 variants from families with the hereditary diffuse gastric cancer (HDGC) syndrome. METHODS: Relevant literature dating from 1998 to 2021 was systematically searched for data on CDH1 gene. The Wilcoxon rank sum test and the Chi-square test were used to estimate if the difference observed between patients with gastric cancer (GC) and unaffected individuals was significant. RESULTS: We identified 80 families fulfilling the established clinical criteria for HDGC CDH1 genetic screening. There were more women than men with DGC and germline CDH1 variant (65.5%). Stratifying the age at diagnosis, we identified an association between DGC, positive CDH1 screening and young women (≤ 40 years) (p = 0.015). The mean age at diagnosis was 39.6 ys for women and 42.5 ys for men. There was an association between CDH1 carrier status and DGC (p = 0.021). CONCLUSIONS: Young women carrying germline CDH1 variants with DGC are comparatively frequent in the HDGC syndrome, and potentially at higher risk to develop DGC particularly in low-incidence areas for GC.