TABLE 2.
Classification of different subtypes of inherited hemochromatosis detailing genetic loci and gene product function
| Classification | Mutant gene product | Gene locus | OMIM | Function |
|---|---|---|---|---|
| Type 1 (most common) | Protein encoded by hfe | 6p21.3 | 235200 | Duodenal crypt body iron sensor |
| Type 2 (juvenile) | Unknown | 1q21 | 602390 | Unknown |
| HAMP | 19q13 | 606464 | Hepcidin antimicrobial peptide | |
| Type 3 | TFR2 | 7q22 | 604250 | Low-affinity transferrin receptor |
| Type 4 | Ferroportin 1/IREG1/MTP1 (SLC11A3) | 2q32 | 604653/606069 | Intestinal iron exporter ferroportin 1 |
| Type 5 | H-ferritin | 11q12-q13 | 134770 | Ferritin heavy chain 1 (FTH1) |