Renal tubular involvement mimicking Bartter syndrome in a patient with Kearns-Sayre syndrome

J Pediatr. 1990 Jun;116(6):904-10. doi: 10.1016/s0022-3476(05)80648-1.


A 10-year-old boy had short stature, external ophthalmoplegia, atypical retinal pigmentary degeneration, and sensorineural hearing loss (Kearns-Sayre syndrome). In addition to ragged-red fibers observed on modified Gomori trichrome staining, there were scattered fibers exhibiting no cytochrome c oxidase activity, indicating a focal deficiency. Cytochrome c oxidase and other respiratory chain enzyme activities were normal biochemically. The patient also had renal tubular dysfunction, including isosthenuria, decreased urine-concentrating ability, and excessive excretion of potassium and magnesium. In addition, he had hyperreninemia and hyperaldosteronism but no hypertension. The renal dysfunction was thought to have resulted from a primary defect in the thick ascending limb of the loop of Henle, mimicking Bartter syndrome. In contrast to previously described cases of cytochrome c oxidase deficiency with de Toni-Fanconi Debré syndrome, the patient had less intensive muscle abnormalities. A renal biopsy specimen showed ultrastructural changes in mitochondria that were similar to those seen in biopsy specimens of muscle. A large-scale deletion (8.8 kilobases) in mitochondrial DNA was found in biopsy specimens of muscle and kidney.

Publication types

  • Case Reports

MeSH terms

  • Bartter Syndrome / pathology*
  • Child
  • Cytochrome-c Oxidase Deficiency
  • Diagnosis, Differential
  • Electrocardiography
  • Humans
  • Hyperaldosteronism / pathology*
  • Kearns-Sayre Syndrome / pathology*
  • Kidney Tubules / enzymology
  • Kidney Tubules / pathology*
  • Male
  • Mitochondria / ultrastructure
  • Mitochondria, Muscle / ultrastructure
  • Muscles / enzymology
  • Muscles / pathology
  • Ophthalmoplegia / pathology*