Heterogeneous pattern of selective pressure for PRRT2 in human populations, but no association with autism spectrum disorders

PLoS One. 2014 Mar 3;9(3):e88600. doi: 10.1371/journal.pone.0088600. eCollection 2014.

Abstract

Inherited and de novo genomic imbalances at chromosome 16p11.2 are associated with autism spectrum disorders (ASD), but the causative genes remain unknown. Among the genes located in this region, PRRT2 codes for a member of the synaptic SNARE complex that allows the release of synaptic vesicles. PRRT2 is a candidate gene for ASD since homozygote mutations are associated with intellectual disability and heterozygote mutations cause benign infantile seizures, paroxysmal dyskinesia, or hemiplegic migraine. Here, we explored the contribution of PRRT2 mutations in ASD by screening its coding part in a large sample of 1578 individuals including 431 individuals with ASD, 186 controls and 961 individuals from the human genome Diversity Panel. We detected 24 nonsynonymous variants, 1 frameshift (A217PfsX8) and 1 in-frame deletion of 6 bp (p.A361_P362del). The frameshift mutation was observed in a control with no history of neurological or psychiatric disorders. The p.A361_P362del was observed in two individuals with autism from sub-Saharan African origin. Overall, the frequency of PRRT2 deleterious variants was not different between individuals with ASD and controls. Remarkably, PRRT2 displays a highly significant excess of nonsynonymous (pN) vs synonymous (pS) mutations in Asia (pN/pS = 4.85) and Europe (pN/pS = 1.62) compared with Africa (pN/pS = 0.26; Asia vs Africa: P = 0.000087; Europe vs Africa P = 0.00035; Europe vs Asia P = P = 0.084). We also showed that whole genome amplification performed through rolling cycle amplification could artificially introduce the A217PfsX8 mutation indicating that this technology should not be performed prior to PRRT2 mutation screening. In summary, our results do not support a role for PRRT2 coding sequence variants in ASD, but provide an ascertainment of its genetic variability in worldwide populations that should help researchers and clinicians to better investigate the role of PRRT2 in human diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Case-Control Studies
  • Child Development Disorders, Pervasive / genetics*
  • Chromosomes, Human, Pair 16
  • Genetic Variation
  • Heterozygote
  • Humans
  • Membrane Proteins / genetics*
  • Mutation
  • Nerve Tissue Proteins / genetics*

Substances

  • Membrane Proteins
  • Nerve Tissue Proteins
  • PRRT2 protein, human

Grants and funding

This work was funded by the Institut Pasteur, CNRS, INSERM, AP-HP, University Paris Diderot, the Bettencourt-Schueller foundation, the Orange foundation, the FondaMental foundation, the Conny-Maeva foundation, the Cognacq-Jay foundation, the ANR (SynDivAutism), Neuron-ERANET (EUHF-AUTISM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.