Increased serum transferrin receptor concentrations in Friedreich ataxia

Mitochondrial iron accumulation is thought to underlie the pathophysiology of Friedreich ataxia and may occur at the expense of cytosolic iron. Decrea ses in cytosolic iron induce expression of the transferrin receptor, some o f which is released into the serum. Here, we demonstrate that serum transfe rrin receptor concentrations are increased in patients with Friedreich atax ia, which supports the hypothesis that it is a disease of abnormal intracel lular iron distribution.