Neutral lipid-storage disease with myopathy and extended phenotype with novel PNPLA2 mutation

Muscle Nerve. 2016 Apr;53(4):644-8. doi: 10.1002/mus.24983. Epub 2016 Feb 22.

Abstract

Introduction: Neutral lipid-storage disease with myopathy is caused by mutations in PNPLA2, which produce skeletal and cardiac myopathy. We report a man with multiorgan neutral lipid storage and unusual multisystem clinical involvement, including cognitive impairment.

Methods: Quantitative brain MRI with voxel-based morphometry and extended neuropsychological assessment were performed. In parallel, the coding sequences and intron/exon boundaries of the PNPLA2 gene were screened by direct sequencing.

Results: Neuropsychological assessment revealed global cognitive impairment, and brain MRI showed reduced gray matter volume in the temporal lobes. Molecular characterization revealed a novel homozygous mutation in exon 5 of PNPLA2 (c.714C>A), resulting in a premature stop codon (p.Cys238*).

Conclusions: Some PNPLA2 mutations, such as the one described here, may present with an extended phenotype, including brain involvement. In these cases, complete neuropsychological testing, combined with quantitative brain MRI, may help to characterize and quantify cognitive impairment.

Keywords: PNPLA2 mutation; brain; cognitive impairment; myopathy; neutral lipid-storage disease.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adult
  • Cognition Disorders / diagnosis
  • Cognition Disorders / genetics
  • Cognition Disorders / psychology
  • Humans
  • Lipase / genetics*
  • Lipid Metabolism, Inborn Errors / diagnosis*
  • Lipid Metabolism, Inborn Errors / genetics*
  • Lipid Metabolism, Inborn Errors / psychology
  • Male
  • Muscular Diseases / diagnosis*
  • Muscular Diseases / genetics*
  • Muscular Diseases / psychology
  • Mutation / genetics*
  • Phenotype*

Substances

  • Lipase
  • PNPLA2 protein, human

Supplementary concepts

  • Neutral Lipid Storage Disease with Myopathy