The CRC from the carrier of in cis variants MLH1: c.-[28A > G; 7C > T] was diagnosed at 35 years of age, showed “patchy” loss of MLH1/PMS2 by IHC in both tumour and adjacent normal cells, with mean β of 0.14 in MLH1 promoter (Table 2 and Additional file 2: Fig. S1C). Here, PMS2 is linked to colorectal carcinoma.