Irida Syndrome

Watchlist

(log in to enable)

Retrieved

2021-01-23

Source

Orphanet

Trials

—

Genes

TMPRSS6, LPIN2, ACVR1, IREB2, HBA2, HBA1, WAS, TEK, SMPD1, PSMB8, HBB, SMAD4, WIPF1, IRX5, HAMP, SRD5A3, HBD, SLC29A3, HBG1, GDF2, ENG, ACVRL1, ATRX, CP, PUS1, FECH, AGGF1, SLC11A2, DMRT1, CHMP2B

TMPRSS6, LPIN2, ACVR1, IREB2, HBA2, HBA1, WAS, TEK, SMPD1, PSMB8, HBB, SMAD4, WIPF1, IRX5, HAMP, SRD5A3, HBD, SLC29A3, HBG1, GDF2, ENG, ACVRL1, ATRX, CP, PUS1, FECH, AGGF1, SLC11A2, DMRT1, CHMP2B, TFRC, ALAS2, EPO, DNM2, SLC25A38, CAT, HJV, BDH2, STEAP3, ERFE, ACO1, TRNT1, TFR2, PCBP1, IDUA, HFE, HBG2, FABP3, BMP1, ALB, LDLR

Drugs

—

Interested in hearing about new therapies?

IRIDA (Iron-refractory iron deficiency anemia) syndrome is a rare autosomal recessive iron metabolism disorder characterized by iron deficiency anemia (hypochromic, microcytic) that is often unresponsive to oral iron intake and partially responsive to parenteral iron treatment.

Epidemiology

50 patients from 32 families of different ethnic origin have been described to date; however, it is likely that this condition is underdiagnosed.

Clinical description

Most IRIDA patients have no major clinical signs, except for pallor, and have normal growth and development. The degree of anemia is mostly mild and more pronounced during childhood. If anemia is severe, they may present with weakness, fatigue, dizziness and exercise-induced dyspnea. Laboratory tests show hypochromic, microcytic anemia with very low serum iron and transferrin saturation levels and normal/high serum hepcidin values. Serum ferritin levels are mostly within the normal range, or even slightly elevated after intravenous iron treatment.

Etiology

IRIDA syndrome is due to mutations the TMPRSS6 gene encoding Matriptase 2, a transmembrane serine protease that plays an essential role in down-regulating hepcidin, the key regulator of iron homeostasis.

Diagnostic methods

Laboratory tests show hypochromic, microcytic anemia with very low serum iron and transferrin saturation levels and normal/high serum hepcidin values. Serum ferritin levels are mostly within the normal range, or even slightly elevated after intravenous iron treatment. Molecular testing confirms the diagnosis.

Genetic counseling

Transmission is autosomal recessive.