Think Gene - Latest Comments in Absence of “High Penetrance” in SNP Genomic Services

Re: Absence of “High Penetrance” in SNP Genomic Services

889 — Fri, 10 Jul 2009 06:35:33 -0000

High penetrance genes testing is not included in SNP. Why is that so?

Re: Absence of “High Penetrance” in SNP Genomic Services

david788990 — Fri, 10 Jul 2009 05:49:57 -0000

What is the relevance of low penetrating genes?

Re: Absence of “High Penetrance” in SNP Genomic Services

spsdel99 — Thu, 18 Jun 2009 13:08:32 -0000

The SNP services offer tests that are somehow related to medical field.So it is relevant inspite of the fact that it offers little benefit.

Re: Absence of “High Penetrance” in SNP Genomic Services

Steven Murphy MD — Wed, 26 Nov 2008 10:27:18 -0000

The official line is that low penetrance genes are more common and thus more relevant. From Dr. Nierenberg of Navigenics:

“In the case of the BRCA genes, only a relatively small proportion of the population – as low as 5% - carry one or more of these genes. We are focused on SNPs that are apparent within whole populations. We make it clear in our literature that we do not test for this type of gene.”

Yeah, and it just so happens that the 10% (not 5%) actually has medically actionable validity....

-Steve

Re: Absence of “High Penetrance” in SNP Genomic Services

Michael Nierenberg — Wed, 22 Oct 2008 13:43:48 -0000

Mr. Andrew Yates offers the following comment in Absence of “High Penetrance” in SNP Genomic Services about espousing the uselessness of genetic testing by companies such as Navigenics:
“The reality is that except for a few enthusiasts (like anyone in the DNA Network, including myself), existing SNP genomic services just aren’t that useful. It’s not useful to know that one has a 7% lifetime risk rather than a 5%. I need to know risks of about 40% and higher.”
In response to Mr. Andrew Yates I offer the following information about lifetime risk assessments offered by Navigenics (www.navigenics.com).
On the Navigenics HealthCompass six conditions have a lifetime risk potential that exceeds 35% (Five conditions exceed 40%). Since some conditions are less common in the population, it is useful to also consider relative risk, as opposed to absolute risk.
Half of all 23 conditions reported have a relative risk (compared to the average genetic risk in the general population) greater than 2; seven conditions, greater than 3; and three conditions greater than 4. For comparison, this level of relative risk is in line with other well-accepted, commonly used risk factors such as positive family history and environmental risk factors (high lipids, age at menopause etc.)

I hope this clarifies things for Mr. Yates who can now feel better about being an enthusiast.
I would also ask Mr. Yates to reconsider his statement about why Navigenics is not doing BRCA testing. Patent considerations aside, it is of import only in about 5% of breast cancer cases (those with “extreme” positive family histories and early age of onset). The contribution of BRCA1/2 mutations in sporadic breast cancers has not been determined conclusively. Our preference is truly to offer a test that is applicable to the majority of individuals. We are cognizant that in a minority of people BRCA testing is important and have addressed this issue on our web site in several places. We realize that no test is complete in and of itself; otherwise people would have heart surgery based only on a treadmill. So, I would ask Mr. Yates to please give us credit for more than trying to get around patent considerations. We are enthusiasts as well.

Re: Absence of “High Penetrance” in SNP Genomic Services

John C — Wed, 04 Jun 2008 15:19:26 -0000

Kevin speaks of those pesky sequences that are patented which makes the genomic information services seem so worthless. But...faith....one just may glean some certainity of data by comparing it with data that is certiain such as the SNPs for blue eyes and the person has blue eyes; this could be a baseline however crude. Also a disorder would have more than one SNP associated with it such as a possibility for a defective neuron being combined with something that would suggest Autism would make the possibility for a disorder in the Autism family to be more certain than not (note, I did not say probability, that is another matter).

Re: Absence of “High Penetrance” in SNP Genomic Services

Kevin — Tue, 03 Jun 2008 17:03:02 -0000

Steve: I don't disagree, but that is the logic the SNP services are using... we'll see how long it holds up.

Re: Absence of “High Penetrance” in SNP Genomic Services

Steven Murphy MD — Tue, 03 Jun 2008 09:44:59 -0000

It is all medically useful or useless. Either way it IS medicine. Test for disease risk? Then you are performing medicine. Check out the state laws in 42 of our great States.

-Steve
www.thegenesherpa.blogspot.com

Re: Absence of “High Penetrance” in SNP Genomic Services

Kevin — Tue, 03 Jun 2008 01:36:55 -0000

The SNP services also can't offer these tests because they are too medically useful. They are too firmly established as medical tests to be sold as informational tests. So they can only sell newly discovered, not patented, tests which aren't as good as the older medical tests. If they give people actionable medical information, it becomes very difficult to argue that the test is for informational purposes only.