Detection of SQSTM1/P392L post-zygotic mutations in Paget's disease of bone

Hum Genet. 2015 Jan;134(1):53-65. doi: 10.1007/s00439-014-1488-3. Epub 2014 Sep 21.

Abstract

Paget's disease of bone (PDB) is transmitted, in one-third of cases, in an autosomal dominant mode of inheritance with incomplete penetrance. The SQSTM1/P392L germinal mutation is the most common mutation associated with PDB. Given the focal nature of PDB, one team of investigators showed that SQSTM1/P392L somatic mutations could occur in pagetic bone lesions in the absence of germinal mutations detectable in the peripheral blood. The objectives of this study were to develop a reliable method to detect SQSTM1/P392L post-zygotic mutations, by optimizing a polymerase chain reaction (PCR)-clamping method reported to be effective in detecting post-zygotic mutations in peripheral blood from patients with fibrous dysplasia; and to evaluate the frequency of this post-zygotic mutation in PDB patients. We used a locked nucleic acid (LNA) specifically designed for the SQSTM1/P392L mutation, which blocks the wild-type allele amplification during the PCR. DNA from 376 pagetic patients and 297 controls, all without any SQSTM1/P392L germinal mutation, was analyzed. We found that 4.8 % of PDB patients and 1.4 % of controls were carriers of this post-zygotic mutation [p = 0.013, OR 3.68 (1.23; 11.00)]. PDB patient carriers of a post-zygotic mutation had a lower number of affected bones and Renier's index than patients carrying a germinal mutation, suggesting a lower disease extension. We also demonstrated that this post-zygotic mutation was restricted to the monocytic lineage. These results confirmed that LNA PCR clamping is effective for the detection of SQSTM1/P392L post-zygotic mutations, which may occur in patients with PDB.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics*
  • Adolescent
  • Adult
  • Aged
  • Case-Control Studies
  • DNA Mutational Analysis
  • Female
  • Follow-Up Studies
  • Genetic Association Studies
  • Humans
  • Male
  • Middle Aged
  • Mutation / genetics*
  • Osteitis Deformans / genetics*
  • Osteitis Deformans / pathology
  • Polymerase Chain Reaction / methods
  • Prognosis
  • Sequestosome-1 Protein
  • Young Adult
  • Zygote*

Substances

  • Adaptor Proteins, Signal Transducing
  • SQSTM1 protein, human
  • Sequestosome-1 Protein