Progressive myoclonus epilepsy with nephropathy C1q due to SCARB2/LIMP-2 deficiency: clinical report of two siblings

Seizure. 2011 Nov;20(9):738-40. doi: 10.1016/j.seizure.2011.06.018. Epub 2011 Jul 22.

Abstract

Action myoclonus-renal failure syndrome (AMRF) is considered a rare form of progressive myoclonus epilepsy (PME) associated with renal failure. A mutation on the gene encoding the lysosomal integral membrane protein type 2-LIMP-2 (SCARB2), the receptor responsible for targeting glucocerebrosidase to the lysosomes, was recently described, allowing a better understanding of its etiopathogenesis. We describe clinically two sisters with AMRF that resulted from a mutation in the SCARB2 gene. The renal involvement was due to nephropathy C1q. When substrate-reduction therapy, to correct the possible glucocerebroside storage in the cells with glucocerebrosidase deficiency, was administered to one of the siblings, a significant improvement was observed. This report points out a rational for a therapeutical approach to this new lysossomopathy.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Complement C1q / genetics*
  • Fatal Outcome
  • Female
  • Humans
  • Lysosomal Membrane Proteins / deficiency*
  • Lysosomal Membrane Proteins / genetics*
  • Lysosomes / genetics
  • Lysosomes / metabolism
  • Myoclonic Epilepsies, Progressive / complications
  • Myoclonic Epilepsies, Progressive / genetics*
  • Myoclonic Epilepsies, Progressive / metabolism
  • Receptors, Scavenger / deficiency*
  • Receptors, Scavenger / genetics*
  • Renal Insufficiency / complications
  • Renal Insufficiency / genetics*
  • Renal Insufficiency / metabolism
  • Siblings
  • Young Adult

Substances

  • Lysosomal Membrane Proteins
  • Receptors, Scavenger
  • SCARB2 protein, human
  • Complement C1q