Vulnerability genes or plasticity genes?
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Vulnerability genes or plasticity genes?
Mol Psychiatry. 2009 Aug;14(8):746-54
Authors: Belsky J, Jonassaint C, Pluess M, Stanton M, Brummett B, Williams R
The classic diathesis-stress framework, which views some individuals as particularly vulnerable to adversity, informs virtually all psychiatric research on behavior-gene-environment (G x E) interaction. An alternative framework of ‘differential susceptibility’ is proposed, one which regards those most susceptible to adversity because of their genetic make up as simultaneously most likely to benefit from supportive or enriching experiences-or even just the absence of adversity. Recent G x E findings consistent with this perspective and involving monoamine oxidase-A, 5-HTTLPR (5-hydroxytryptamine-linked polymorphic region polymorphism) and dopamine receptor D4 (DRD4) are reviewed for illustrative purposes. Results considered suggest that putative ‘vulnerability genes’ or ‘risk alleles’ might, at times, be more appropriately conceptualized as ‘plasticity genes’, because they seem to make individuals more susceptible to environmental influences-for better and for worse.
PMID: 19455150 [PubMed – indexed for MEDLINE]
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Meaning: There are genes which confer genetic variability (“plasticity”) to the gene pool – much like skin color, height, hair color, etc. These genes may be either adaptive or maladaptive depending on the environment where the person lives. The genes are not strictly maladaptive (“vulnerability”) but may have good or bad properties depending on the environment.
For example, the genetic predisposition toward hypothyroidism is adaptative prehistorically when humans frequently faced famine since those with hypothyroidism would tend to conserve their stores of energy better (e.g. fat and muscle stores) and would thus have a longer lifespan. Yet this same genes are maladapative in modern times, where food is plentiful, since they also increase the risk for diabetes, heart disease, cancer, etc. – and thus would shorten lifespan.