Thursday, May 28, 2015

Genetic Testing's Downside

Finally someone did a study about a lot of genetic tests. And the results were not that good.

Allow me to state that I have never been a fan of genetic tests. I am not someone who is going to go out and have any genetic tests, any more than I am going to get my palm read or see a fortune teller. I have no desire whatsoever to find out what could be in store for me. I have enough going on currently without worrying about the future as well.

The thing about genetic tests is they tell you if you have a gene mutation or variant that could show an  increased or decreased risk for something. Some of the things could be minor, like getting gray hair younger (like my siblings) or a propensity for wrinkles. Some things could be major, like cancer or a heart condition.

Genetic tests tell you what you could have happen. But they do not tell you what the risk is. The only way to know the risk is for test results compared to other test results and their health issues. The data must be shared. But not all labs share their data.

"...  not all gene mutations, or variants, are equal. Some raise risk a lot, others just a little, and some not at all. Most are of unknown significance - a quandary for doctors and patients alike. And most variants are uncommon, making it even tougher to figure out which ones matter and how much.

To solve these mysteries and give patients better information, the U.S. government several years ago helped form and fund ClinVar, a database for researchers around the world to pool gene findings, coded to keep patients' identities confidential. More than 300 labs contribute to it, including universities such as Harvard and Emory and some private companies such as Ambry Genetics and GeneDX."

"...So far, the project has tracked more than 172,000 variants in nearly 23,000 genes, a small portion of the millions known to exist but some of the more common ones that have been identified.

More than 118,000 of these variants have an effect on the risk for a disease - and 11 percent have been analyzed by more than one lab so results can be compared. In 17 percent of those cases, labs interpreted the findings differently, as either raising the risk of a disease, having no effect on it or having an unknown effect.

At least 415 gene variants now have different interpretations that could sway a medical decision, such as whether to have healthy breasts or ovaries removed to lower the risk of cancer, or to get a medical device such as an implanted defibrillator to cut the risk of sudden cardiac death."

The first problem is not all labs interpret the results the same way and then the problem of what to do about them surfaces. Data sharing will help with these problems as more data is shared and compared.

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