Research Viewpoints Clinical Phenotypes of Mitochondrial Diseases

Viewpoint On

Parasyri M, Brandström P, Uusimaa J, Ostergaard E, Hikmat O, Isohanni P, Naess K, de Coo I.F.M, Nascimento Osorio A, Nuutinen M, Lindberg C, Bindoff L.A, Tulinius M, Darin N, Sofou K: Renal Phenotype in Mitochondrial Diseases: A Multicenter Study. Kidney Diseases DOI 10.1159/000521148

Disorders of mitochondria (MT), often due to mutations of the MT genome, are uncommon and usually present in infancy or childhood. The kidney aspects of these disorders are quite varied.

Parasyri and coworkers conducted a, multi-institutional retrospective cohort study (m=36) using data collected by the European Consortium of the Mitochondrial Clinical Research Network (MCRN). The median age of onset was 2 years (range pre-natal to 67 years). Kidney manifestations were the first sign of MT disease in about 20% of the subjects. Anemia, hearing impairment, epilepsy and multi-organ involvement was common. Fanconi syndrome was present in about 15% of the subjects. Acute kidney injury was the presenting feature in about 20% and chronic kidney disease in about 75% of patients. About 10% 0f the cases had MELAS (Mitochondrial Encephalopathy, Lactic Acidosis and Stroke –like Episodes). Interestingly Cystatin C eGFR was more accurate measure than eGFR creatinine in these cases.

The study provides wealth of information concerning the diagnosis and prognosis of these rare diseases.