SINGAPORE - As consumer genetic testing takes off in Singapore, the Health Ministry (MOH) is doubling down on efforts to warn people of the risks.

These include the possibility that test results are not backed by strong scientific evidence, or that testing companies may sell genetic data to third-party organisations, it said.

To raise awareness, the ministry has run ongoing social media advertisements urging caution since December last year. This followed the publication of a 13-page guidance document for testing companies last May and a separate advisory for consumers last August.

The aim is to guide consumers' expectations and help the public make safer decisions, given that such tests have been more widely advertised in recent years, an MOH spokesman told The Straits Times.

Consumer genetic tests claim to offer personalised insights on an individual's genetic make-up including ancestry, skin type and fitness profile.

These services are offered by overseas businesses such as 23andMe and Circle DNA, as well as firms with offices in Singapore such as Imagene Labs, e-beauty and easyDNA.

Customers are typically sent a kit with instructions on how to collect a saliva sample, which is then mailed back to the firm for processing.

The MOH spokesman said it does not track the number of consumer genetic test providers in Singapore and has not received any complaints to date.

While genetic tests used in healthcare settings are evaluated and registered by the Health Sciences Authority, those sold directly to consumers are not regulated, she added.

Its HealthWatch website cautions people to be wary of claims that sound too good to be true and to read the fine print before taking any test: "Be cautious in interpreting the genetic test results, which may not always be reliable. Talk to your doctor before making any health decisions."

Dr David Klinzing, general manager of Imagene Labs, said its test reports are written in consultation with subject matter experts, in a way that makes them easily understood and acted on by the average person. It offers a variety of tests, ranging from those focused on fitness to nutrition and healthy ageing.

"If a customer requires more guidance on interpreting the results, we provide such a service by request through referral to qualified professionals that can aid in a customer's specific goals and objectives," he added.

A spokesman for e-beauty, which offers tests to determine skin type and overall health, said customers get a free consultation to help them interpret their test results. While they can consider acting on minor lifestyle changes, such as getting more exercise, they should seek medical advice regarding disease risks.

"After all, a genetic test serves only as a reference, is not definite and does not serve as a clinical or diagnostic tool in any way," she said.

Another spokesman for easyDNA, which offers ancestry tests as well as those to determine familial relationships, added: "We always highlight to clients that genetics are only a component of health, environment and other factors have major influences too."

All three companies said demand has grown in recent months and added that customer information is kept confidential.

Two lecturers from Singapore Polytechnic's School of Chemical and Life Sciences noted that results from such tests should not be used to assess, diagnose or treat health issues.

As a general rule, all genetic test results should be interpreted alongside factors such as a person's medical history, said Drs Tan Tuan Lin and Edmund Lui in a joint response.

The accuracy of such tests depends on various factors, including the technology used for testing, added Dr Chew Joon Lin, a senior lecturer from Ngee Ann Polytechnic's School of Life Sciences and Chemical Technology.

For example, tests may not include all the relevant genetic variations or mutations that impact a certain trait. This could lead to unreliable interpretations of the results.

"Different companies may provide conflicting results because each company uses different variant data sets, technologies and literature sources in their testing and interpretation of results," she said.