Serum MT I + II level by MT2A A-5G genotype. Serum MT (I+II) level was measured with a competitive ELISA. MT levels are plotted around the median as box plots, where the dots represent individual data. Diamonds and the whiskers represents the mean and SD of MT levels. Whiskers of the box plots extend to 1.5× interquartile range, where the values exceeding or falling below this level are marked as outliers. The overall median was 10.9 ng/ml, and mean ± SD was 11.7 ± 10.1 ng/ml. The numbers of samples was 95, 69, and 15 for AA, GA, and GG genotypes, respectively. There was no significant difference in serum MT levels among the genotypes (analysis of variance: P = .61).