One of our interesting findings is that de novo APC c.4666dupA (p.Thr1556AsnfsX3), which has been reported to cause an aggressive Gardner syndrome in a 2-year-old European boy (Kiessling et al., 2019), reproduced as a pancreatic, duodenal and colorectal cancer phenotype in a 104-year-old Japanese woman (Table 2). This evidence concerns the gene APC and Gardner syndrome.