moblog – Tsun Leung Chan is now reporting a heritable germline epimutation of MSH2 in a family with hereditary colorectal cancer another case of “paranormal” inheritance. They find a mosaic germline methylation pattern (which might even be a symptom of another mutation that affects the demethylation-de novo methylation pattern of MSH2 during embryogenesis?). If my hypothesis is true these families should even show more genes with different methylation patterns, yea, yea.
Another attempt to answer this question comes by a study of the MLH1 promotor
Pro: MLH1 promoter methylation was found in a patient and his mother giving evidence for a familial predisposition for an epimutation in MLH1. Contra: a de novo set-up of methylation in one patient, a mosaic or incomplete methylation pattern in six patients, and no evidence for inheritance of MLH1 promoter methylation in the remaining families.