The Times asked a panel of medical experts to review the results of Mark Henderson’s genetic scan.

The experts were Professor Shirley Hodgson, clinical geneticist, St George’s Hospital, London; Paul Pharoah, cancer geneticist, Cambridge University; Imran Rafi, GP and member of the Primary Care Genetics Society; Glen Brice, genetic counsellor, St George’s Hospital.

Kari Stefansson, chief executive of deCODEme, responded to their comments.

FALSE REASSURANCE
A big concern was that results could provide false reassurance to people with a family history of cancer. The service screens for common variants that affect breast, colon and prostate cancer, but not for major mutations that greatly raise risk.

Professor Hodgson “If my mother and sister have died of breast cancer because of [a major mutation], and I come out of this with a less than average risk, it may be completely wrong because it’s not testing for the gene that’s causing cancer in my family.”

Dr Pharoah “A low-risk result doesn’t negate your family history, but people may interpret it as if it does.”

Dr Stefansson “These are important criticisms and we will address them. Our site doesn’t make this sufficiently clear. We will change it, we don’t want to give false impressions.”

RISK AND AGE
The results do not assess how risks change with age.

Dr Pharoah “Most people who are going to get asthma are going to get it by the time they’re 20. This lifetime risk of 18 per cent hasn’t taken into account the fact that you’ve got to 33 without developing asthma.”

Dr Stefansson “This is a good point. Risk does change with age, and we are working on ways to reflect that.”

COUNSELLING
The experts were worried that people were tested for a variant that confers a high risk of Alzheimer’s, about which nothing can be done, without any counselling.

Dr Pharoah “You would worry for the rest of your life, and when you get to the age of 60, and start forgetting something, you’d start thinking, ‘Ooh, am I getting the first symptoms?’. ”

Mr Brice “This can cause real psychological distress. You really do need to have pretest counselling before this is done.”

Dr Stefansson “We are going to have to disagree. I resent the patronising view I should have a genetic counsellor next to me.”

INTERPRETATION
The panel felt many people would struggle to interpret the results, and approach GPs who would be poorly placed to advise them.

Dr Rafi “Are GPs really going to be able to interpret these risk generations? I don’t think they are going to be familiar with the scientific information behind this.”

Dr Stefansson “I’m not going to be held responsible for the poor education of GPs. This helps to empower the patient.”

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