Expensive online DNA tests are 'no more accurate than horoscopes'

Expensive online DNA testing services which promise to unlock the secrets of your ancestors are a waste of money, a study has found.

And some offer sinister sidelines that include potentially alarming warnings about vulnerability to life-threatening illnesses, such as cancer.

The consumer group Which? has found that DNA testing websites, which are part of a booming industry in tracing family trees, are not as harmless as they may appear.

Some keep DNA records for up to 20 years or share them with outside companies for commercial benefit.

It is possible that a customer could find their DNA is matched with a stranger, proving a family link that perhaps had been kept a secret.

And it could throw up uncomfortable questions if the DNA profile of a father turns out to be different from that of his children.

Experts at Which? Computing sent DNA samples to four companies, two from a man and two from a woman.

The companies boast they can go much deeper than a simple family tree to provide information that 'describes your genetic heritage to the beginning of humanity in Africa'.

Dissatisfied customer: Penny Law had three tests

However, the tests, which cost £75-£510, generally provided such vague information that they were little better than horoscopes, Which? reported.

The firms used by Which? included 23andMe.com, Oxfordancestors. com, Ancestry.co.uk and DNAsolutions.co.uk.

Which? Computing editor Sarah Kidner said: 'One company, 23andMe, seemed to be hedging its bets when it said that the DNA sample came from somebody of Polish, Arab or Irish decent.

'In reality the results were so broad that it's the equivalent of telling people what their star sign is. But while you can read horoscopes for free, the cheapest online DNA test costs £75.'

One customer, Penny Law, was fascinated by the growth in the DNA heritage industry and decided to have three tests done.

But the results from each company were so different, she concluded they might be a rip-off and at best should be treated as fun.

One suggested her origins were in East Asia, another said Spain and the last came up with the Near East.

Miss Law, deputy editor of Ancestors magazine, said: 'All the companies were working from the same DNA with the same technology, so to come back with different results is suspicious. Heritage DNA tests should be treated as fun. You can't rely on them.'

Which? said the testing services are not regulated in any way. And it was alarmed to find that some of the companies used the DNA tests for their own purposes and might share them with other organisations for research.

Miss Kidner said: 'Interest in genealogy has increased massively due to programmes such as Who Do You Think You Are? but people need to be wary of DNA testing services.'