Guest Post Today, Hopefully he doesn't get Flamed!

Before you read this post.....I want to make one last comment. Before you could spit and give your DNA......Your blood had to be drawn. Sometimes....many, many, tubes. I feel that if we still required blood all of these arguments would fall to the wayside. But now that is not the case. It seems to me that Spit has turned patients into a commodity. This dehumanizes all of us. Well, at least I feel this way.

Now to the post..Unedited...

I would like to thank the Gene Sherpa for giving me the chance to provide a guest posting. As a non-medical professional and a consumer who has not had his genome sequenced for a genetic mutation that could put me at risk for a genetic health condition, I assume that a consumer who has a genetic test done from a personal genome company might get a test result similar to the following: "these results do not guarantee that you will or will not develop breast cancer.

Please keep in mind that many other genetic and environmental factors are likely to play a role in development of breast cancer when interpreting these results." As a result, the consumer has a test result that they can't do anything about. Even if the patient takes this test result to a genetic health professional, the health professional can't rely on the test result because it didn't go through proper testing and counseling protocol. When a consumer meets with a trained genetic health professional, the consumer will have a detailed family history done to see what risk(s) he/she has of developing breast cancer (or any other genetic health condition) or passing a genetic mutation to an offspring and learn about which genetic test they would benefit the most from...with leaving the option up to the consumer to have the test done or not.

A negative test result means that person doesn't have a particular disease, doesn't have an increased risk of developing the disease, or isn't a carrier of the disease. This is misleading. When a genetic test is done, a certain region of a gene is analyzed for a change in the DNA sequence. Previous studies will have already indicated a link between a specific SNP(s) to disease correlation. The region of the DNA that was tested may have come back negative, but that still doesn't mean a mutation hasn't occurred in that gene. There is a possibility that a mutation can occur in a region of a gene that puts a person at risk for developing the health condition they were tested negative for.

It is important to know the region that a mutation occurs in a gene. This is important information to know for clinical outcome because the region of the gene mutation can affect the function and folding of a protein and the drug interaction(s). For instance, a patient can test positive for a genetic test but the medicine has no affect on disease progression.

In a case like this, there is a likelihood that the gene mutation that is leading to the disease phenotype (if it even is a gene mutation) has occurred in a different region within the same gene or a different gene all together (and could also need dose adjustments). Knowing the region of the gene mutation can lead to better clinical treatment. Some personal genome companies market their tests so that at-home genetic tests can measure the risk of developing a particular disease, like heart disease, diabetes, or breast cancer. Most of these tests are developed after a single published finding. A genetic test should not be developed until after the previous findings have been replicated. It is also essential to know the population carrier rates and incidence rates to give accurate risk(s) of developing a condition.
I would like to use breast cancer to illustrate the above information. How does breast cancer occur?
- Hereditary
- Reproduction
- Hormone(s)
- Age and sex
- Environmental
- Diet

Guidelines for genetic testing and counseling:
• The population screened must have a significant burden of suffering
• Preventive intervention must be superior to conventional follow-up
• There must be an asymptomatic period during which the disease can be detected in the clinical setting
• Screening must be accurate during the asymptomatic period
• The screening test is acceptable to the patient Important information:
• There is no difference in specific rates of death among carriers and non carriers for a BRCA founder mutation. It is generally assumed that carriers of BRCA mutation have a higher risk of death, but studies have found this not to be the case.
• Ipsilateral disease has shown to have no increase rate of death for BRCA1 and BRCA2 founder mutations .
• There is no difference in the outcome after chemotherapy treatment among either BRCA1/2 mutations, but location of the mutation in BRCA1/2 has shown to affect chemotherapy treatment.
• The size of tumor, receptor type, and nodule presence does not affect mortality rate.
• The aggressiveness of tumor affects mortality rate, which is dependent on the type of genetic mutation.
• The specific survival rate is worse for BRCA1 mutation carriers then non-carriers, but not for BRCA2…the reasons for the differences are the incidence rate among the general population. • The tumor size is not a predictor for probability of death and advanced stage at diagnosis does not affect outcome.

It is important for a consumer to make sure they understand the benefits and limits of any test before undergoing the test. For a consumer that orders a genetic test from a personal genome company, do they know that the personal genome companies don't interpret the results? This leads to the consumer interpreting the test results. To my knowledge, no at-home genetic tests has been reviewed by the FDA.

This post was written by Jonathon Weber. Mr. Weber works as a Research Associate for Kromosoft. Mr. Weber is interested in wanting to become a genetic counselor.

The Sherpa Says:
While I agree with most of what Jonathon Weber has said. He too presents some old data and has some incorrect commentary. Despite this, he is very well versed for an recent Undergrad. He is an anomaly......But it is clear, there are some undergrads who appreciate the complexity of these tests. Too bad there are many Graduates who do not...