Using heterologous expression, we have characterized some properties of TMPRSS6 variant V736A and mutant V795I identified in Hep3B and HepG2 cell lines, respectively, and an uncharacterized mutant (G603R), found in two patients suffering from IRIDA12,13, thus providing insight into the molecular basis of IRIDA. Here, TMPRSS6 is linked to IRIDA syndrome.