A case of iron-refractory iron deficiency anemia

Key words: Microcytic anemia, Abnormal iron absorption and iron utilization, Autosomal recessive inheritance

Iron-refractory iron deficiency anemia (IRIDA) is an autosomal recessive disorder characterized by: congenital hypochromic, microcytic anemia, very low mean corpuscular erythrocyte volume, low transferring saturation, poor response to oral iron supplementation (abnormal iron absorption) and partial response to parenteral iron therapy (abnormal iron utilization). IRIDA has recently been shown to be caused by mutations in the gene TMPRSS6 (located on the chromosome 22), which encodes a transmembrane serine-protease expressed by the liver, which modulates hepcidin. Hepcidin promotes the internalization and degradation of ferroportin in lysosomes. As a consequence, both iron absorption from the intestine and iron release from macrophage stores are inhibited.