


First of all hats off to Oliver Chu, the brave boy from California who has just undergone a successful trial of stem cell therapy for a terrible condition called Hunters Syndrome. [1] as Ian Sample of the Guardian explains. It’s caused by a simple mutation in a gene called IDS-1 which controls the production of a vital enzyme Iduronate-2-sulfatase; without which the body cannot break down key sugars, leading to organ damage of all sorts and cognitive decline. The trick has been to extract the stem cells from Oliver’s blood: replace the faulty gene with a true copy using a viral vector; and pop them back in to Oliver, whenceforth they will thrive happily, self reproducing from their own line, and producing bountiful quantities of the enzyme for life.
And this for us is the key part. Let’s repeat : the new stem cells with the engineered gene will start their own self replicating line. In Oliver. Now Oliver himself started from a single stem cell-a single fertilised ovum, as do all living things. With DNA that was used to build every single following cell as it grew . An Ur stem cell if you like. But now. young Oliver has two. All the cells from his original cell, Plus the new line, from the engineered stem cell. whose line is now flooding his system with the good enzyme..
The central tenet of biology up to now is that we all of us-tigers, pterodactyls, humans, whatever-have a single unmodifiable line of DNA in our cells. Random variations may be passed to the next generation and tested by Natural Selection. But the actual DNA deep in the cells cannot be changed or modified. That’s the Darwinian positioned its held up pretty well for centuries. The alternative, proposed by Lamarck is that organisms are modified by the environment and this information can be learned inthe genes and passed on. So far there has been no evidence to support this view whatsoever . But what if the environment contains clever humans who can choose to modify DNA, and thereby create what are in effect hybrid organisms with two separate DNA lines-like young Oliver? Is this Darwinian? It’s not how it happens in nature, and its been done by force majeur. But it sounds a lot like Lamarckism from where we sit.
#stem cells #hunters syndrome #darwin #lamarck #evolution #medicine #health


























