Genetic disorders of iron overload and the novel "ferroportin disease
: a systematic meta-analysis of clinical and molecular findings.
On the other hand, alterations in SLC40A1 (ferroportin) cause iron overload (15,16); in its classic form, however, this disorder, termed ferroportin disease, has clinical and biological presentations that are considerably different from HH (17).
The 1st class of mutations leads to the originally described ferroportin disease, and the 2nd class displays a phenotype indistinguishable from HH.
Phlebotomies, the main treatment for iron overload in nonanemic patients, are a well-tolerated and effective way to treat HH, but they can lead to anemia in class 1 ferroportin disease (17) and are contraindicated in HHCS.
The ferroportin disease. Blood Cells Mol Dis 2004;32:131-8.
In addition, collaborators from several medical centers in The Netherlands provided urine and serum samples from 3 patients with distinct forms of hereditary hemochromatosis not associated with the hemochromatosis (HFE) gene [Online Mendelian Inheritance in Man (OMIM) type 2a, homozygous G320V HJV variation (11); OMIM type 4, N144H-caused ferroportin disease (12)].
In this study, we found serum and urine hepcidin concentrations close to zero in 2 brothers treated for juvenile hemochromatosis (OMIM type 2a) and values in the upper level of the reference range for a patient treated for ferroportin disease (OMIM type 4; see Table 1 in the online Data Supplement).
Ferroportin disease has distinctive features compared with HFE-related hemochromatosis.
Diagnosis of ferroportin disease is complex because it requires that all various conditions causing isolated hyperferritinemia are ruled out.
Because clinical data will accumulate with time and in vitro and experimental studies in mice and humans will be performed, it will undoubtedly become clear whether this first classification of ferroportin disease is still useful or needs to be adjusted based on new insights.
If a patient also has a marginally decreased hemoglobin, increased hepcidin, or poorly tolerates phlebotomy, ferroportin disease should be considered.