FDA approves home genetic tests for 10 diseases

The US Food and Drug Administration (FDA) has approved the first genetic test to estimate an individual's risk of disease that can be sold directly to consumers. The decision could pave the way for the production of further direct-to-consumer (DTC) tests for disease risk in the US.

The FDA granted marketing authorisation to biotechnology company, 23andMe, to sell its Personal Genome Service genetic health risk (GHR) report on the US market, which includes information about a customer's predisposition to certain diseases and conditions, including Alzheimer's and Parkinson's disease.

The test requires customers to send a saliva sample to the company, which checks the DNA contained for over 500,000 genetic markers. The customer's report is then made available online between six to eight weeks later, along with an interpretation of the results.

The tests cannot determine a person's overall likelihood of developing a disease, since many non-genetic factors also contribute to this risk, but will provide a personalised risk estimate of predisposition towards 10 diseases, including factor XI deficiency, Gaucher disease type 1 and coeliac disease.

Customers will need to specify if they want to receive information about their risk estimate for Alzheimer's and Parkinson's disease, which are tested separately, but the company will offer this information free of charge as part of the GHR report if the customer so chooses.

DTC testing for health risk has sparked controversy in part due to the complexity of genetic disease risk, and also the potential lifestyle changes that test results can result in (see BioNews 788). In 2013, the FDA blocked 23andMe from selling its health-related personal genome tests, stipulating that they first had to prove their accuracy amid concerns that genetic test results can mislead customers about their health (see BioNews 733).

Previously, the FDA has only approved DTC genetic tests for diseases that could affect future children, and in 2015 23andMe obtained permission from the FDA to market a test for carrier status of 36 genetic diseases, including cystic fibrosis (see BioNews 825).

However, speaking about the latest announcement, Anne Wojcicki, chief executive and co-founder of 23andMe, explained that the latest test went beyond informing customers of carrier status: 'The difference between then and now is that now we have authorisation to tell you about your personal risk.'

The FDA has introduced 'special controls' that establish the accuracy and reliability of GHR tests, making it quicker and easier to get this and similar products to market. 'The special controls describe the testing that 23andMe conducted to demonstrate the performance of these tests and clarify agency expectations for developers of other GHRs,' said Dr Jeffrey Shuren, director of the FDA's Center for Devices and Radiological Health.

The FDA said that it has reviewed the accuracy of 23andMe's GHR tests based on data from scientific literature that link specific genetic variants to a risk of the diseases. It also required 'user comprehension studies' to verify that the test reports could be easily understood by all customers – it was found that more than 90 percent of the information was understood. However, while 23andMe offers links to counsellors, patients will need to pay for this separately.

Commenting on the approval, Arthur Caplan, a bioethicist at New York University, said: 'So much remains unknown, both about the accuracy of the testing and the ability of consumers to process genetic information without counselling or help.'

'This decision may wind up frightening as many people as it does empower them,' he said.

However, some studies have shown that the psychological impact of genetic tests is not as severe as some people fear. Professor Robert Green, a medical geneticist at Harvard Medical School, reported that 'in some cases people did not realise what they were saying yes to and others did not realise the psychological impact it would have on them'.

'There is some potential for distress, but it is much, much smaller than was anticipated,' he added.

A personal genome service provided by 23andMe that estimates a person's genetic risk for ovarian and breast cancer, Alzheimer's disease, and other traits like baldness has been available in the UK since 2014 (see BioNews 783). According to Wojcicki, there have been 'no untoward incidents.'

The US testing kit for the 10 diseases, which also provides an ancestry report, currently costs $199.