Correlation of IgE levels with COMT SNP rs4680. Serum of 54 CFS patients was analyzed for IgE. Patients were group in either Met/Met, Met/Val, or the wild type variant Val/Val. Enhanced IgE levels are defined >100 U/ml (dashed line). Statistic analysis was performed with two-tailed Chi-Square/Fisher’s exact test with *p < 0.05 between Met/Met or Met/Val and the variant Val/Val.