In five patients, there was a pathogenic/likely pathogenic mutation in another gene: RAD50 p.E723Gfs*5/Class 5 (one patient with breast cancer), RAD50 p.E723Gfs*5/Class 5 (one patient with nonpolyposis colorectal cancer), APC p.N1739fs/Class 5 (one patient with polyposis), NF1 p.N2220Ifs*25/Class 5 (one patient with family history of breast cancer) and SDHB p.P56Yfs*5/Class 5 (one patient with renal cancer). Here, SDHB is linked to polyposis.