Disease Coded in the Genome?

Since the human genome was sequenced, over 10 years ago, hardly a week has gone by without some new genetic "breakthrough" being reported. Last week five new "genes for Alzheimer's disease" generated sometimes front-page coverage across the globe. But take a closer look and the reality is very different.

Among all the genetic findings for common illnesses, such as heart disease, cancer and mental illnesses, only a handful are of genuine significance for human health. Faulty genes rarely cause, or even mildly predispose us, to disease, and as a consequence the science of human genetics is in deep crisis.

The human genome sequencing project was based on a huge, but calculated, gamble. The then leaders-to-be of the project believed that faulty genes inherited from our parents were probably the cause of most disease. After all, many rarer diseases were already known to be genetic. So it seemed a small leap to suppose that inherited faulty genes would underlie common diseases, too.

There was, however, a problem with the basis for their confidence.…

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