Fig. 3.

Analysis of the dose of MLH1 alleles at rs1799977 (c.655A>G). a Schematic representation of the MLH1 epimutation found in case 29. Promoter methylation is associated with the c.-93G allele (in approximately 2% of cells), located in cis with exonic c.655G allele, which showed subtle reduced transcriptional activity in blood. In concordance, the MLH1 c.655A allele showed LOH in the three tumor lesions developed by the proband. b Allele-specific expression (ASE) analysis at MLH1 c.655G>A in cDNA derived from leukocytes of case 29 and two heterozygous controls. A slightly diminished expression of the c.655G allele was observed. c Loss of heterozygosity (LOH) analysis in tumors from case 29. Allele specific values show loss of the c.655A allele in all three tumors