Senior doctors call for crackdown on home genetic test kits | Science

Experienced doctors have called for a stringent crackdown on genetic testing on consumers, following an influx of patients who were wrongly told that they were carrying dangerous mutations related to cancer or dementia. 39, other devastating conditions.

The companies improperly informed women that they had defective BRCA genes, which present a high risk of bad and ovarian cancers. One patient had to undergo preventive bad removal surgery after a genetic test performed by a consumer revealed to her a BRCA mutation. The intervention was canceled at the last moment when an NHS laboratory revealed that the result was a false positive.

Doctors warn that the problem is weighing more and more heavily on NHS practices and genetic clinics, which face the consequences when patients get alarming or confusing results.

"The NHS is incredibly irritated by these results because [in the case of BRCA] they are more often than not right, "said Professor Anneke Lucbaden, Clinical Geneticist at the University of Southampton and President of the British Society for Genetic Medicine. Lucbaden said it was "terrifying" that one of his patients – and perhaps others – had planned irreversible bad surgery on the basis of erroneous results.

"I do not say prohibit these tests, but they need more regulation," she said.

A recent badysis of a genetic test chip used by direct-to-consumer companies revealed that, in the case of typical mutations in the BRCA gene causing disease, when the test gave a positive result, it was much more Probably not to be wrong.

Lucbaden said that she is personally aware of almost 10 cases of patients having been referred to genetic services after being tested positive for BRCA mutations or bowel cancer, problems being experienced. are revealed later when NHS labs performed more rigorous tests. "I think that's the tip of the iceberg," she said.

Consumer genetic testing, offering health and ancestor information, has gained increasing popularity in recent years, with hundreds of thousands of people in the United Kingdom thinking they have been tested. Major consumer genetic societies, such as 23andMe or AncestryDNA, typically offer only ancestry tests or health readings limited to a handful of conditions. However, consumers can download their raw genetic data and send it to third-party companies, which, for as little as £ 20, provide results and badysis on thousands of genes.

The problem is that the chip technology used by 23andMe and AncestryDNA is not designed to give accurate results for rare mutations, information on which secondary companies, such as Promethease and LiveWello.

Although these companies normally claim that any result should not be treated as a medical diagnosis, consumers – and even doctors – may not be aware of how unreliable these results may be.

A recent badysis of a commercially available microarray revealed that it was just 17% of the time when it detected a rare pathogenic BRCA mutation of the type that significantly increases the risk of bad and ovarian cancer. It was also found that the test was missing more than half of those with actual BRCA mutations. In a dataset of nearly 50,000 people, there is concern that negative results may not rebadure people with a family history of bad cancer.

Caroline Wright, a genomics researcher at Exeter University who led the badysis, said, "The results are shocking. At the moment they are so bad, you have to think about not sharing the data. This can be very detrimental for the individual if he discovers this information completely erroneous. "

Wright said the genotyping chips used by some companies might show slightly better performance, but that this technology is basically not designed to detect rare mutations.

Lucbaden explained how one of her patients had been scheduled for a double mastectomy on the basis of erroneous findings during the redesign of genetic badysis in NHS laboratories, which use more powerful genotyping techniques. When repeated tests became negative, Lucbaden stated that the patient asked, "Can I still have surgery just to be safe?" Although she was finally deterred, "she was not safe." was not at all rebadured to find that it was a false positive, "Lucbaden said.

Jan Cobben, a clinical genetics consultant at Northwick Park Hospital in northwestern London, said he has encountered two separate cases of positive parents looking for deafness-related mutations and thinking that genes could affect their children. In one case, the family had a deaf child and thought they had found an explanation. A different group of parents had been confronted with the fairly common frustration that their child often seemed to ignore what they said, but the genetic result caused him to fear a serious underlying health problem.

"They think," Oh my God, it's linked, "said Cobben," There is a hearing gene where abnormalities are not very rare. "We repeated the test and the supposed anomaly was a normal variant. "

Cobben said that he would advise anyone considering a private genetic screening: "Stay away, do not do it." "You should not do any medical tests for no reason," he said. "It's a basic medical principle."

In response to questions, Kwame Iwegbue, CEO of LiveWello, who conducts a secondary badysis of the DNA data, said that the company does not alert customers about the risk of false-positive or false-negative results, because it is "qualities of diagnostic tests". "LiveWello does not provide any diagnostic test," he said.

Iwegbue said it was "absolutely" reasonable that NHS clinics cover the costs of interpreting and validating private genetic tests. "One of the direct consequences of accessing third-party online tools, such as LiveWello, and access to ubiquitous sources of online medical knowledge, is that patients are today" They are more autonomous and better informed, "he said. "At a minimum, the information they get from these sources provides arguments for a more rewarding doctor-patient encounter … If the information presented by the patient is false, the doctor can take this opportunity to explain the reasons, and then present to the patient what he considers to be the correct information. "

Greg Lennon, co-founder of Promethease, said: "When we can, we specifically warn our users of possible payment errors and we also remind people that the reported badociations depend on the accuracy of the data."

Lennon sent screenshots of sample reports in which a false positive would be likely, which obviously warned the user about this possibility.

A spokesperson for 23andMe said, "There is a distinction between validated variants that we report in our … reports and uncommitted raw data that customers can choose to download on their own. We do not advise our clients to use third-party interpretation services and note the risks of doing so very clearly on our website and in the 23andMe accounts of our clients. "