Pliotropy

Pleiotropy refers to the phenomenon where one genetic variant can have multiple phenotypic consequences.

1. Dr. Jonathan Anomaly on Pleiotropy: An example is a genetic variant in East Asians that causes both dry earwax and low body odor. This shows how a single genetic change can have multiple effects. Manipulating genes without understanding their full range of consequences can inadvertently cause undesirable traits to be selected along with desirable ones 1.

2. Steve Hsu on Ashkenazi Jews: Ashkenazi Jews exhibit a higher incidence of certain nervous system disorders, possibly due to pleiotropy linked with their higher average intelligence. This is likely due to both genetic bottlenecks and pleiotropy, suggesting intelligence might come with certain negative health trade-offs 2.

3. Robert Plomin with Sam Harris: They discuss how each DNA difference impacts many traits, highlighting the complexity and interconnectedness of genetic influences. This complexity necessitates a move away from simple gene-trait associations towards understanding genes within network contexts 3.

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     1

     Genetic Consequences

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     2

     Genetic Potential

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     3

     Genetics and Complex Traits

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     4

     Genetic Attraction Signals

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     5

     Systems Medicine Revolution

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4. Dr. Jonathan Anomaly on Facial Symmetry: Facial symmetry and certain aesthetic traits tend to be markers of genetic health due to positive pleiotropy. Selecting for these traits can unintentionally select for overall better health 4.

5. Manolis Kellis on On-Target Side Effects: When a designed molecule targets a gene that is pleiotropic, it can affect multiple traits, demonstrating the multifunctionality and interconnectedness within genetic networks. Future medical interventions may need to address these networks holistically rather than focusing on single genes 5.

In summary, pleiotropy underscores the complexity of genetics, where single genes or genetic changes can have wide-ranging effects, necessitating a holistic approach to genetic research and intervention.