Round-up March 13 – April 25

Three topics have dominated genomics happenings. First, polygenic scores: the science continues to mature, there are calls for their rapid clinical integration, there are concerns about their use, and there are commercially available products. Second, how to regulate human germline modification. Third, use of genomics in forensics.

 

Polygenic scores

  • Polygenic scores for cognitive traits like IQ and Educational Attainment are confounded by gene-environment effects, especially socioeconomic status. Preprint from Plomin and team. Within family predictions were ~60% lower than between family predictions for these traits, but not for traits like BMI and height. The difference disappeared after accounting for SES, suggesting that SES is part of “passive gene environment correlation” or “genetic nurture”. All genetic influences operate via the environment. Three genotype-environment correlation (rGE) mechanisms:

Passive rGE: “Parents generate family environments consistent with their own genotypes, which in turn facilitate the development of the offspring trait, thus inducing a correlation between offspring genotype and family environment ”  

Active rGE: children select, modify and create experiences

Evocative rGE: children evoke responses in their environment (correlated to their genetic propensities.)

Within family genetic differences can include active and evocative rGE effects, but not passive rGE effects, which are shared within the family.

If aiming just to maximize trait prediction, using between family based scores (i.e. calculated from unrelated individuals) is legitimate. But for causal analysis, including the use of Mendelian Randomization, within family designs are necessary.

  • Another pre-print examining the “nature of nurture”, gene-environment correlations in the context of educational attainment which also had access to the polygenic scores for the mothers. They show that both mothers’ and children’s polygenic scores are predictive of parenting style. And also that mothers genetics predicted childhood educational attainment beyond direct transmission, mostly via providing a stimulating cognitive environment.

 

Germline genetic modification: moratorium or no?

 

Forensics

  • Rwanda is proposing a DNA database of all its citizens for fighting crime purposes. The plan is in its earliest stages, no legislation has yet been passed. In 2015 Kuwait proposed a similar database for fighting terrorism, but it was later struck down by the constitutional court.
  • FamilyTreeDNA let the FBU access genetic data without telling its customers, and faced a backlash for it. Now customers can opt out from law enforcement access to their data. But the company doesn’t want its customers to do that, and has launched Ad campaigns on that premise, stating it feels it has a “moral responsibility” to help solve cases.
  • Meanwhile, the growth of GEDMatch, the platform that consumers can choose to upload their genetic test results to in full knowledge that law enforcement have access to it, coupled with the ability that up to 4th cousins can be identified from these uploads, is leading to a “National DNA database by default”. So states Natalie Ram in Slate, who calls for ending familial searching, and points to a Bill in Maryland that hopes to do just that.
  • An example of DNA being used for more than an ID. In a murder case, police sequenced DNA found on the victim and found that it belonged to a black man, which changed their search strategy. They then asked nearly 400 black men who had been taken into custody in the region for DNA samples, as part of a “Race-biased dragnet”.
  • An apartment complex on Long Island is setting up a registry of the DNA of residents’ dogs, and will test dog poop to punish those dog owners that do to clean up after their pets.

 

Science

 

Applications

 

Regulation

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