title: Fibroblast growth factor 21: a novel biomarker for human muscle-manifesting mitochondrial disorders.
abstract: BACKGROUND
  Diagnosis of mitochondrial disorders is challenging, because of their highly variable clinical manifestations and age-of-onset and the shortage of specific diagnostic tools. Recent molecular studies have found that serum fibroblast growth factor 21 (FGF21) has potential to be a biomarker for muscle-manifesting mitochondrial disease, as well as for follow-up of disease progression and effect of intervention.
  
  
  METHODS
  Serum FGF21 as a biomarker is compared to conventional serum diagnostic tools for mitochondrial disorders.
  
  
  CONCLUSIONS
  Mitochondrial disorders are a large group of different progressive disorders, with the age-of-onset from neonatal life to late adulthood, and symptoms originating from any organ system but sharing an underlying cause of mitochondrial dysfunction. The prevalence of these disorders is about 1:2000, varying somewhat between different countries. Serum diagnostic tools include lactate, pyruvate, their ratio, creatine kinase and amino acids. However, none of these markers are both sensitive and specific. Increased levels of FGF21 cytokine were recently found in the serum of patients, who have a muscle-manifesting mitochondrial disease, thus providing a promising, novel, sensitive and specific biomarker for these disorders.
authors.affiliation: University of Helsinki, Research Programs Unit, Molecular Neurology, Biomedicum-Helsinki, Haartmaninkatu 8, Helsinki 00290, Finland. anu.wartiovaara@helsinki.fi
authors.forename: Anu
authors.initials: A
authors.lastname: Suomalainen
mesh_terms: D015415:Biomarkers / Q000097:blood; D005346:Fibroblast Growth Factors / Q000097:blood*; D006801:Humans; D017240:Mitochondrial Myopathies / Q000097:blood*; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers; C414620:fibroblast growth factor 21; D005346:Fibroblast Growth Factors