Experts have expressed some concern over the availability of DIY genetic tests and have launched guidelines for the industry.

A number of private companies offer direct-to-consumer tests that can estimate the person's risk of diseases such as cancer, based on information in their genes.

The Human Genetics Commission is concerned that people are buying kits online without counseling or enough information to interpret the results.

This can leave some of those falsely reassured or unnecessarily worried, they say.

Most of the tests are offered by US companies but can be gotten via the internet in any country.

Purchasers of the test send of a cheeck swab for lab analysis that will inform them of their likelihood of getting a number of ailments such as heart disease, diabetes, Alzheimer's, Huntington's or breast cancer.

The industry has little regulation, and the HGC says that this could mean patients could be given misinformation without any clinical support.

The HGC says that tests for serious genetic diseases, like Huntington's and breast cancer, should only be given with the offer of counseling before and after testing.

Companies much make it clear whether the possible outcomes of taking the test are, and what patients can do about the results.

Patients should also be given simple information on how genetic tests work.

Claims made about tests should be supported by evidence that is published in scientific journals, says the HGC.

The guidelines are not required, but the HGC is hopeful that they will achieve the desired effect and say that they are a better option than laws and regulation.

Chairman of the HGC Dr Jonathan Montgomery, who helped draw the guidelines, said they had settled on some 'off the shelf' principles that could be used everywhere.

"It's a bit like a kite mark for the industry.

"There is more to be gained from codifying good practice than pushing for regulation or legislation."

Stricter rules are still needed.

The Patients Association said, "Such guidelines are important and while we applaud the efforts being made to protect vulnerable patients, we have serious concerns that some patients may fall through the net of self-regulation and become victims of unscrupulous providers.

"Patients should always consult a healthcare professional before embarking on such purchases to ensure they have access to the full services that they may need."

Chief Executive of the consumer group Which?, Peter Vicary-Smith, said, "This set of principles from the HGC is a positive first step to address those risks in the absence of formal regulations, but we do feel they could go further.

"For example, tests for serious hereditary diseases should only be provided through medical professionals."

Public health minister Anne Milton praised the HGC for "showing much-needed leadership in cracking down on this".

"People deserve to have confidence that the tests they choose are evidence based and that they fully understand what the results mean," she said.