Showing posts with label genetics and health. Show all posts
Showing posts with label genetics and health. Show all posts

Wednesday, May 2, 2007

Gene Doping in Athletes



This week in EMBO reports (European Molecular Biology Organization) the dreaded issue of gene doping rears its ugly head. Normally I only report on genetics pertinent to your health. However this raises special interest for me. I was a college athlete and am fascinated by the extremes to which we would go to shave off that 0.5 second. This article raises significant questions about using gene therapy to enhance performance. Where will we stop, what line will be drawn? Gene therapy to cure disease....Why isn't weakness a disease? What about poor vision? We allow athletes to have LASIK, why not gene therapy? The danger is gene overdose. Once introduced into the body we have very poor mechanisms to control expression. But for that extra 0.5 seconds is it worth it? What about for those extra 200 points on the SAT?

The natural extension for these test yourself companies is now treat yourself. Are you a 100lb weakling? What about being predisposed to obesity? Treat yourself. Would you?

Sunday, April 22, 2007

Drug overcomes mutations

Today in the Times Online an article introduces a new type of medication. Called PTC124, this medication allows ribosomes to "pass-over" nonsense mutations, allowing for fully transcribed protein. The functional properties of PTC124 are similar to the aminoglycoside antibiotic gentamicin, but the two compounds are chemically distinct and PTC124 does not exhibit any antibiotic characteristics. In vitro experiments showed PTC124 to be superior to gentamicin at ribosomal read-through of nonsense mutations. Currently the drug has passed Phase II trials of Duchenne Muscular Dystrophy and of Cystic Fibrosis

If we look at disease burden in rare genetic diseases, nonsense mutations(mutations coding for a stop sequence in the middle transcription, resulting in a truncated protein/mRNA) make up a significant amount of afflicted patients. Here is a press release from the company. It does turn out that this company is privately held, but I am sure Genzyme or another company is looking for a new M&A target.

Here's what the Gene Sherpa says, PTC124 could hold tremendous promise however I will await phase III trial results. There are always unanticipated outcomes, possibly tumorigenesis(cancer creation). Trials are currently recruiting if you are interested.That being said, we may see the development of other molecules designed to overcome our genetic shortcomings.

Lastly I just want to be perfectly clear about what I had said in a previous email. It may alienate me from other blogs, or hired gun blogs for certain DTC testing companies. Just look for the Gene Sherpa link. If it's gone on your favorite blogs, then chances are we have a shill.
When Han Solo told Luke that travelling through Lightspeed isn't like dusting crops I am certain he was talking about genetic testing. In home testing has no place in this world, unless it is guided by a TRAINED professional. I hope too many people will not be harmed by this senseless promotion of testing without counseling. No offense to other doctorates, but I took an oath to help or at least do no harm. Primum Non Nocere Unfortunately, most of the professionals marketing these tests have not. The physicians employed by them perhaps have forgotten this oath.

Wednesday, April 18, 2007

Personalized Medicine is coming

I am back! What a fun week in San Diego. I was at a conference for Program Directors (Responsible for training resident physicians) in Internal Medicine. During my absence a few things have come up. But first I want to talk about the conference and how almost all program directors acknowledged that they do not teach genetics in their curriculum. Moreover, several expressed interest in our curriculum. I am so excited that these teachers are now realizing the power of genomic medicine.
That being said.....Appropriate use of the genome brings great results. Misuse and blatant promotion such as that done by a direct to consumer testing center in San Francisco (I will not say their name) will only lead to sullying of the geneticists' reputations.
On Genetics and Health there is a post which lead me to a website that was promoting risk factor testing for diabetes. Like any other path I will lead you through, there is good, bad, and unknown. First the good.
Diabetes is an awful disease and the longer it is untreated the worse the outcomes. So naturally I am excited about being able to diagnose it quicker. BUT this test does not diagnose, it only shows increased risk.
Here comes the bad.
In fact, the risk of carrying this gene polymorphism is not even half as much as having a sibling with Type 2 diabetes. Why would a company promote this test rather than promote taking a family history? The answer is simple, because they make MONEY off the test or interpretation and not off taking a family history and counseling in person. I have no respect for that. In fact, people will be amazed to know that this company makes all of its profit from marking up test costs or non face to face services, and serving as an "educational" resource. What education leaves out that the best screening test for hemochromatosis is iron studies? Shame on them.
Lastly, the unknown.
Now that I know this risk, how do I use it clinically. There is no study showing that metformin or a PPAR gamma here will prevent the onset of diabetes in this risk group. What I am saying is....before we go down this road 3 things need to be done

  1. A 3 generation family history
  2. Research on prevention in this high risk group
  3. Companies looking to make a quick buck off of you on testing without clinical utility need to be punished. Or at least I can lead you away from that confusing and dangerous path.

If you do wish to do in home testing without the help of a TRAINED genetic specialist who examines you and takes a full family history, then you risk the difficulty of test interpretation, appropriate follow up, and possibly improper care as a result. I hope you choose wisely.

Tuesday, April 3, 2007

Genes for Heart Attack Risk/Prostate Cancer Risk

This week in the American Journal of Human Genetics 2 articles about genetic risk for heart attack are published. The findings raise hope of future therapeutic targets and identification of risks. The first study implicates the KALRN gene and an intronic(noncoding) SNP. This polymorphism(change in a gene) was found in almost all Caucasians with early heart attack. What does this mean? Very little so far. The results need to be replicated... But more importantly this gene operates in a totally different system than cholesterol in creating atherosclerotic plaques! The second study is more limited in scope and is less important for pan-ethnicity and only applies to French Canadians.

The news is just as exciting for African Americans as new studies implicated and corroborate other findings that a gene polymorphism could be responsible for up to 2/3rds of prostate cancer in this ethnic group. This set of data may lead to early detection or even prevention. This is the goal of all Personalized Medicine specialists....including myself!