Evidence for contribution of epigenetic mechanisms in the pathogenesis of systemic mast cell activation disease.

Recently, evidence was provided for common familial occurrence of systemic mast cell activation disease (MCAD), i.e., mast cell disorders characterized by aberrant release of mast cell mediators and/or accumulation of pathological mast cells in potentially any tissue. Since there is accumulating evidence that epigenetic processes may have transgenerational consequences, the aim of the present study was to investigate by two different experimental approaches whether epigenetic effects may contribute to the familial occurrence of MCAD. (1) High throughput profiling of the methylation status of the genomic DNA in leukocytes from MCAD patients in comparison to healthy subjects revealed for the first time an association of MCAD with alterations in DNA methylation comprising genes encoding proteins crucially involved in DNA/RNA repair and processing, apoptosis, cell activity, and exocytosis/cell communication. A set of 195 differentially methylated CpG sites could be regarded as candidates for a MCAD signature at the methylation level of the DNA. (2) In a cohort of MCAD patients, a correlation between age at symptom onset and year of birth (reflecting different generations) was observed suggesting the presence of the phenomenon of anticipation. In conclusion, the present findings suggest that epigenetic processes could substantially contribute to the transgenerational transmission of MCAD.