Had one of his parents been slightly less fortunate in their choice of a mate, James Watson might not have helped discover the structure of DNA in 1953. Instead, he would have been born deaf, and then lost his sight as he became a teenager. Equally, as he is, had he been less fortunate in the genetic lottery when he chose his wife, either of their sons might have had the same fate.
This is because Watson’s complete DNA – his genome – contains a single gene for Usher’s syndrome, an inherited disorder which affects hearing and sight. Watson’s must have come from one of his parents. Usher’s is a “recessive” disease – you need two copies of the gene to be affected. About five people per 100,000 carry the gene, so Watson’s chances of being disabled weren’t large. But they were real.
The rapidly falling cost and time needed to map your DNA
Year Cost Time 2003 $437,000,000 13 years to map 2007 $10,000,000 4 years 2008 $100,000 4 weeks 2012 $100* 2 days