COQ6 mutations in human patients produce nephrotic syndrome with sensorineural deafness

J Clin Invest. 2011 May;121(5):2013-24. doi: 10.1172/JCI45693. Epub 2011 Apr 11.

Abstract

Steroid-resistant nephrotic syndrome (SRNS) is a frequent cause of end-stage renal failure. Identification of single-gene causes of SRNS has generated some insights into its pathogenesis; however, additional genes and disease mechanisms remain obscure, and SRNS continues to be treatment refractory. Here we have identified 6 different mutations in coenzyme Q10 biosynthesis monooxygenase 6 (COQ6) in 13 individuals from 7 families by homozygosity mapping. Each mutation was linked to early-onset SRNS with sensorineural deafness. The deleterious effects of these human COQ6 mutations were validated by their lack of complementation in coq6-deficient yeast. Furthermore, knockdown of Coq6 in podocyte cell lines and coq6 in zebrafish embryos caused apoptosis that was partially reversed by coenzyme Q10 treatment. In rats, COQ6 was located within cell processes and the Golgi apparatus of renal glomerular podocytes and in stria vascularis cells of the inner ear, consistent with an oto-renal disease phenotype. These data suggest that coenzyme Q10-related forms of SRNS and hearing loss can be molecularly identified and potentially treated.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • COS Cells
  • Child
  • Child, Preschool
  • Chlorocebus aethiops
  • HeLa Cells
  • Hearing Loss, Sensorineural / complications
  • Hearing Loss, Sensorineural / genetics*
  • Homozygote
  • Humans
  • Infant
  • Infant, Newborn
  • Intracellular Signaling Peptides and Proteins / genetics
  • Kidney Glomerulus / metabolism
  • Laminin / genetics
  • Membrane Proteins / genetics
  • Mutation*
  • Nephrotic Syndrome / complications
  • Nephrotic Syndrome / genetics*
  • Phenotype
  • Podocytes / metabolism
  • Rats
  • Ubiquinone / genetics*
  • WT1 Proteins / genetics
  • Zebrafish

Substances

  • Intracellular Signaling Peptides and Proteins
  • Laminin
  • Membrane Proteins
  • NPHS2 protein
  • WT1 Proteins
  • nephrin
  • ubiquinone 6
  • laminin beta2
  • Ubiquinone