[extropy-chat] BIO: overtorqing the luddites

[Robert J. Bradbury]

On Mon, 16 Feb 2004, Adrian Tymes, commenting on my comments:

> You have a point, but...in animals taken to full
> term, certain clones have had defects the parent did
> not.  These defects aren't even detectable until years
> after birth...but would be unacceptable for human
> clones, who would be doomed to deformity unless these
> defects are reversed.

No argument.  There are two reasons for this.

The first is the microdeletions (or microinsertions) that
take place as a result of DNA double strand breaks and the
fact that most cloning experiments are using older cells.
The only way out of this is to be able to do genomic
sequencing of the cloned cells (you don't need the
whole genome -- just the 3-10% of it that is important)
to know the genome is in reasonable condition.
This is probably a decade or so away technology to
do it at a cost that couples/governments can afford.

The second problem is the loss of proper gene imprinting
(turning specific genes off) that is normally done during
the gamete production process.  We have the sequences for
the enzymes that manage this in the gene databases but I don't
think we know how to make them work at this point.

But if one bars reproductive cloning on the basis of
the probable increase in genetic defects one rides
into a bioethics swamp.

If you adopt a position that it is illegal to allow
deformed children to be born -- then don't you have to
bar the (informed) birth of children with Down's Syndrome,
Cystic Fibrosis, Muscular Dystrophy and any of the other
5000+ known genetic diseases?  I see little difference
between the legal prohibition of reproductive cloning and
the legal prohibition of sex between parents who may be
known carriers of a disease (or requirements that they
perform genetic testing and abort embryos with genetic
defects).  It is then but a small step to prohibiting
reproduction by people with *any* genetic defect
(and we all probably have 5-10 of them).
You are on a *very* slippery slope.

Robert