[Gllug] Biometrics?

[Dylan]

On Tuesday 24 March 2009, Nix wrote:
>Tandem repeats are, by definition, repetitive regions where DNA
> replication tend to lose its grip and accidentally lengthen on the fly.
> Nothing constrains this to happening in the germ line (although the male
> germ line, at one replication every 14 days, does tend to accumulate a
> lot of mutations of all kinds). There will certainly be cases out there
> of individuals who have different lengths of fingerprinted tandem
> repeats in different parts of their bodies: fingerprinting would, I
> suppose, see such individuals as two or more different people.


There are additional potential problems where the individual has a long-term 
viral infection. HIV, hepatitis, herpes, HPV, even rhinoviruses are all 
involved in horizontal gene transfer; and HIV and HPV actively interfere with 
replication for their own benefit. Indeed, some potentially cancer-triggering 
viruses [0] seem to specifically target STRs and telomeres (presumably 
because they are areas where 'alien' DNA can be 'hidden' from the usual 
error-correcting mechanisms relatively easily.) This means that there is 
ample opportinity for STR mutation, as well as the introduction of viral DNA, 
and even DNA from former hosts of said virus, to at least complicate the 
results.

Dx

[0] HPV can definitely trigger cancers, and there is mounting evidence that 
HIV, Hep-[A|B|C] and herpes also have carcinogenic properties or actions.

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