An individual with Propionic Acidemia in his third decade of life who is cared for in our institution recently developed hearing loss. The patient’s mother  brought to our attention that on one of the family support group websites for Propionic Acidemia she noticed another affected adult wearing hearing aids. This was a complication I had not previously encountered in this disorder. However, in looking through the literature this has been reported before (Brosch S, et al. HNO. 2008 Jan;56(1):37-42; Lam C, et al  Mol Genet Metab. 2011;103:338–40).  It is becoming apparent that many of the later complications of Propionic Acidemia are very reminiscent of classical mitochondrial disorders including sudden onset optic atrophy and now hearing loss.

Hilary Vernon MD PhD