The real question is whether it’s worth the effort and cost. They argue that various benefits might stem from writing a human genome, such as improved resistance to viruses, cancer and prion diseases, and production of stem-cell lines for regenerative medicine.
These are attractive goals – but it’s not yet clear that this is the best way to achieve them.
The main challenge, Church and colleagues say, is to reduce the current cost of synthesising and testing very long DNA sequences (0.1 to 100 billion base pairs; the human genome has 3 billion) by a factor of 1000.
It has been almost unremarked so far that this is really a question of chemistry.
Church and colleagues admit that their scheme is ambitious – they say the estimated cost could of the order of the billion (£2.06 billion) needed for HGP–Read.
But the paper outlining the idea is a fairly modest, even sketchy affair that calls for a ‘consideration of ethical, legal, and societal implications from the start’.
We need this perspective to approach the proposal by George Church of Harvard University, US, and colleagues for a ‘Human Genome Project–Write’ (HGP–Write); the original Human Genome Project being HGP–Read.
Church aims to build a complete human genome from scratch, using the clever synthetic chemistry now routinely used to make much shorter stretches of DNA with specified sequences.