When you purchase through link on our site , we may earn an affiliate commission . Here ’s how it work .
A major defect of the genic tests offered by the Google - back company 23andMe is not necessarily their accuracy , but rather the limited selective information they utilise to evaluate a person ’s life-time risk of complex disease , experts say .
Recently , the Food and Drug Administration sent aletter to 23andMetelling the party to halt marketing its desoxyribonucleic acid testing kit , because the kits necessitate FDA approval , which the company had not obtained . The varsity letter emphasise the pauperism for 23andMe to prove that their tests are accurate .
Direct-to-consumer genetic tests have shortcomings, experts say.
" FDA is interested about the public wellness upshot of inaccurate outcome from the [ Personal Genome Service ] gimmick ; the main purpose of compliance with FDA ’s regulatory necessary is to see that the test work , " the letter of the alphabet interpret , mention to 23andMe ’s genetic testing product . [ 7 Diseases you could Learn About From a Genetic Test ]
However , fit in to one expert , the accuracy of the mental test is not the big effect . The caller ’s testing method acting have been found to meet federal standards for research laboratory testing , called Clinical Laboratory Improvement Amendments ( CLIA ) , said Amy Sturm , a hereditary counselor at The Ohio State University Wexner Medical Center .
A greater problem is that the results allow for " a very uncomplete thought " of a person ’s risk of exposure for a pay disease , Sturm say .
circumscribed view
The society says that its desoxyribonucleic acid examination outfit and analysis — which have been sold in the United States for more than five years , according to the FDA — can tell people whether their genes indicate an increased risk for more than 250 disease and conditions .
To do so , the test discover certain transmissible marker , or single base polymorphism ( SNPs ) , which are single bit inthe DNAthat vary among people and have been link in inquiry field to diseases . But for many of these diseases , the party tests just a few genetic marker , when in reality , many other factor , including additional genetic mark , likely add to the development of the disease , Sturm said .
For example , to assessbreast cancer jeopardy , the test swear on three SNPs within the breast cancer cistron BRCA1 and BRCA2 , and eight other markers ( SNPs ) linked with titty Crab .
" The fact of the affair is … that ’s just such a limited view of breast malignant neoplastic disease genetic science , " Sturm said . researcher suspect that hundreds , if not grand , of genetic marker probably influence tit cancer risk . And so even if the great unwashed do not have those three single nucleotide polymorphism , they could still have a genetic mutation that puts them at risk of exposure for breast cancer .
The company also does not obtain a family history , or take into story environmental factors that may lend to disease endangerment . [ 6 Foods That May sham Breast Cancer Risk ]
For illustration , 23andMe provides a report on a somebody ’s risk oftype 2 diabetes , but genetics kick in to just 26 percent of a person ’s risk , according to the company . The balance is due to environmental factors , such as obesity , physical inactivity and a story of heart disease , 23andMe said . And there are still obscure genetic factors that the examination can not take into account .
" It ’s just a very small snapshot of anyone ’s particular risk , " said Barbara Bernhardt , a genetic counselor and professor of medicine at the University of Pennsylvania School of Medicine .
Sidestep the doctor
While 23andMe does explain that its tests do not take into accounting all of the gene that contribute to disease jeopardy , that wo n’t necessarily stop people from get the wrong idea , Sturm tell .
For exemplar , a few years ago , Sturm counseled a piece who had interrogation about his 23andMe results . The man was very concerned about his risk of esophageal cancer , free-base on his outcome . But after taking the man ’s fellowship history , Sturm found out the man should be more disturbed about heart disease , which run in his family , than esophageal cancer , Sturm said . And the increased peril ofesophageal cancerdiscussed in the 23andMe report was base on a single genetical marker that had been study only in a Chinese universe , Sturm said . ( The man was not Formosan , so it was unclear if the results utilise to him , Sturm said . )
This counsel experience highlights another major offspring withdirect - to - consumer genetic mental testing : consumer can take them without run through their wellness - care providers , expert say .
" The peril is just , most people do not have the educational desktop to fully realize [ the tests ] themselves , what the outcome means , " Sturm say .
Bernhardt agreed . " Since the commencement , the main worry has been about the potential for misunderstanding of the results , and the deficiency of resources that may be available to people to help separate out result , " she say .
If masses ’s outcome show they are at medium danger for a disease , they might be overly reassured by the finding ; and if the results show they are at increase risk , they may seek medical exam that they do not need , Sturm say . For case , the man Sturm rede kept asking if he needed a screening trial for esophageal cancer , when he did not want one .
However , 23andMe does advise consumer to speak with their doctors if they have concerns about their results , and also offers to connect the great unwashed with genetic counselor to explain results . But it ’s unclear how many people take advantage of these services , Sturm say .
In addition , people who take a inherited mental test through their physician would probably undergo pre - test direction to talk about what the results might reveal , and whether the patient role would be ready to deal with such results . People who take the 23andMe trial run do n’t demand to undergo pre - test counsel , even though the results might show a genetic risk for conditions such asAlzheimer ’s disease .
In the past , 23andMe has pronounce that its test are for unpaid purposes , but " from our perspectives , it ’s been passably clear that the data returned to masses are think to have implications for their wellness , " Bernhardt articulate .
The companionship has receive funding from Yuri Milner , Johnson & Johnson Development Corporation , MPM Capital , The Roche Venture Fund , Google Ventures , and New Enterprise Associates , among others .
