H63D, S65C and C282Y allele frequency distribution in 1282 blood donors among different Slovenian regions. A) Regional distribution of HFE polymorphisms. The regions, numbered from 1 to 11, are arranged from west to east, and marked on the map below. Average frequency for Slovenia is presented in the last column (total). In the region 9 H63D allele frequency is significant higher comparing to other regions (p = 0.005). (B) Geographic regions of Slovenia.