BMPR1a DCV carriers do not display massive gastric polyposis (> 100 gastric polyps) [17], with 86% of BMPR1a DCV carriers having < 5 gastric polyps, whereas 17% of SMAD4 DCV carriers had > 100 gastric polyps (p = 0.0001) [4]. This evidence concerns the gene SMAD4 and hyperplastic polyposis syndrome.