FGF21 in ataxia patients with spinocerebellar atrophy and mitochondrial disease

Background: Serum fibroblast growth factor 21 (FGF21) was proven to be a useful biomarker for the presence of mitochondrial neuromuscular disease. Methods: In the present study, we used the difference in the serum FGF21 level to differentiate between ataxia patients with hereditary spinocerebellar atrophy (SCA-ataxia) and those with mitochondrial syndrome (Mito-ataxia). Patients with SCA-ataxia (SCA2, SCA3) and Mito-ataxia (MELAS, MERRF, LHON, maternal inherited hearing impairment mtDNA A1555G mutation) were recruited in this study. All SCA-ataxia patients revealed a consistent pattern of cerebellar atrophy. On the contrary, some of the Mito-ataxia patients exhibited a vascular lesion with cerebellar infarction. Results: Extremely higher levels of serum FGF21 were found in the Mito-ataxia patients with MERRF and MELAS diseases, but not in patients with SCA-ataxia or LHON/mtDNA A1555G mutation. The positive trend between the mtDNA heteroplasmy and serum FGF21 was indicated in either MERRF (P = 0.003, r = 0.923) or MELAS (P = 0.070, r = 0.566) patients. Conclusion: Serum FGF21 can be applied as the first molecular screening among patients suspected to be victims of hereditary ataxia with neuromuscular degeneration prior to mass genetic screening. (C) 2012 Elsevier B.V. All rights reserved.