Single-center experience of four cases with iron-refractory iron deficiency anemia (IRIDA)

Iron refractory iron deficiency anemia (IRIDA) is a rare autosomal recessive type of anemia characterized by unresponsiveness to oral iron therapy and partial response to parenteral iron therapy. In this article, we report the clinical presentation of four patients with IRIDA admitted to our clinic, including their laboratory values at admission and after oral and parenteral iron treatment, and the analysis of their mutation(s) in TMPRSS6 gene.

Four patients from different families, aged between 3 and 14 years, two girls and two boys, two of whom were from consanguineous marriages, who were diagnosed with iron deficiency anemia in primary health care institutions and referred to our clinic because of inadequate response to oral iron treatment were included. Patients were evaluated for the differential diagnosis of microcytic, hypochromic anemia and investigated for the etiology of IDA. Homozygous or compound heterozygous mutations causing defective matriptase-2 protein expression were detected in the TMPRSS6 gene; these mutations included four frameshift mutations-two of which were the same in two cases and causing premature terminal stop codons-and a nonsense mutation, all of which were previously demonstrated in the literature. The response to parental iron therapy ranged from complete non-response to mild to good response in hemoglobin levels, but none of the patients showed improvement in iron parameters.

Increased awareness of IRIDA and keeping it in mind in the differential diagnosis in the presence of hypochromic microcytic anemia that does not respond to iron treatment will be crucial in improving the diagnosis and treatment of the disease and ultimately enhancing the quality of care for affected individuals.