October 3, 2018 Meeting

Genes and Society in the News:

  • Robert Plomin’s new book “Blueprint: How DNA makes us who we are” has been reviewed.
    • Although Plomin was an author of the multi-author paper on the genetics of educational attainment which drew careful conclusions from the data, his own ideas are much more extremely biased towards the influence of genes on behavior.
    • The Guardian review by Andrew Anthony “So is it nature not nurture after all?” was careful and critical.
    • A more critical review was published in Nature 27 Sept 2018. 561:461 “Genetic Determinism Rides Again” by Nathaniel Comfort.
    • Both reviews point out Plomin’s reliance on “polygenic scores” – basically algorithms designed to get a single number expressing the summed-up influence of many sites on DNA (represented by SNPs).  This type of measure, although an improvement over the search for single gene explanation of complex traits, may have some use, but it also leads to a simplistic view of genetic causality.
  • Spotify and Ancestry.com have entered into a partnership to develop playlists based on information from genetic ancestry tests.
  • Schrempft, S., Jaarsveld, C. H., Fisher, A., Herle, M., Smith, A. D., Fildes, A., & Llewellyn, C. H. (2018). Variation in the Heritability of Child Body Mass Index by Obesogenic Home Environment. JAMA Pediatrics. doi:10.1001/jamapediatrics.2018.1508
    • Heritability values were higher for children living in higher risk environments.  Reminded us of studies on heritability of IQ by Turkheimer, but this may be an opposite effect.  His studies showed lower heritability of IQ in poor (high risk) environments.

Discussion points:

  • As our main discussion, we tackled several papers on new databases of examples of “knockouts” in the human genome.
  • Because of an unusual amount of inbreeding these studies have been done on sequences from large numbers of Pakistanis.
  • The results suggest that there are many examples of individuals with homozygous “knockouts” (deletions, chain-termination mutations, splice site modifications etc) who survive to adulthood and often do not exhibit any obvious trait.
  • Certainly, there are many known genetic mechanisms to account for such results. This also demonstrates the potential difficulty in assigning traits to individual genes – even in cases that seem simple.



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