The policy relationship between genetics and liability continues to be that you must take the person as you find them. Vulnerability is only an issue if you as the duty holder should have known and acted upon it. Probabilistic liability exposure however is affected by genetics. Risk rating would be justified even if duty holders are ethically bound to be gene blind.
SE Humphries et al. The Lancet. July (2001) Vol. 357 #9276 p 115.
The effect of genetics on disease risk is illustrated by this article on apolipoprotein genotype in smokers.
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