A pioneer in the field of human DNA testing, Genelex provides comprehensive DNA testing services. Our DNA Drug Sensitivity Testing and GeneMedRx software have helped physicians find the right drug and dose for their pateints since 2000.
Thursday, November 20, 2008
Friday, November 14, 2008
Warfarin DNA Testing Predicted to Save Over One Billion Dollars and Improve Patient Safety
The AEI-Brookings Joint Center for Regulatory Studies released a study in November, Health Care Savings from Personalizing Medicine Using Genetic Testing: The Case of Warfarin that confirms that DNA testing will dramatically improve the safety and effectiveness of Coumadin (warfarin).
Warfarin, brand name Coumadin, is a powerful medicine that saves hundreds of thousands of lives every year. It works by “thinning” the blood and preventing clots that would otherwise cause strokes, heart attacks, or other blood clotting disease. Every year as many as two million Americans start taking warfarin and at any given time there are four or five million on the medicine.
The amount of warfarin required for someone to reach their target INR, the measure of the effectiveness of warfarin, varies as much as forty-fold from person to person. This interpersonal variation in warfarin dose requirement makes it time consuming and dangerous to identify the optimal dose for patients. Dangerous because the therapeutic window, the difference between the effective dose and the toxic dose of warfarin, is exceedingly small. The consequences of warfarin over-dosing are also severe — resulting bruising and bleeding are the second most prevalent cause of emergency room visits and are responsible for thousands of deaths every year. There are some safer, replacement drugs in development, but they are still at least three or four years away from being ready for market.
During the last decade scientists have discovered that most of the individual variation in warfarin dose requirement is due to genetics or variation in the DNA of individual patients. This variation, for which genetic tests are now available at the initiation of warfarin therapy, occurs at two sites on the DNA. The most important, known as CYP2C9, controls the levels of the enzyme that’s responsible for the breakdown and elimination of warfarin. Approximately 35% of the population have variant forms of this enzyme that slow down the elimination of warfarin from the system. Instead of a person reaching their warfarin and INR steady state in four or five days, it can take two weeks or more. Genetic testing is the only reliable way to determine when steady state is reached.
The second most important site of genetic variation affecting warfarin maintenance dose is the vitamin K receptor (VKORC1), the site of action of warfarin. This makes sense as it is well known that vitamin K intake affects the action of warfarin. Genetic variation is common at this site. Ninety percent of Asian-Americans have the "low-dose" variation: meaning they required a lower dose of warfarin, while most African-Americans have the "high-dose" variation requiring more drug to get adequately anticoagulated. Patients of European descent fall somewhere in the middle.
When people have DNA testing there are now computer programs that take into account their genetics, age, sex, weight and other factors, such as amiodarone or other medicines they may be taking to calculate their warfarin dose. This calculated dose is many times more accurate than the dose determined without the DNA testing.
Patients need to be proactive in obtaining this testing. Adoption of the testing by doctors and anticoagulation clinics is slow, despite endorsement by leading scientists, the FDA, and patients who have had the testing and credit it with saving them from the dire consequences of a warfarin overdose. Additionally, uptake has been slow because of the inherent conservatism of the medical establishment and lack-luster interest from pharmaceutical manufacturers.
Widespread adoption of DNA testing to predict warfarin dose will cut down on doctor and emergency room visits and save thousands of lives. A recent Brookings/American Enterprise Institute study estimates that routine use of DNA testing would save the healthcare system as much as $2 Billion per year. It will also help make warfarin therapy more accessible to the millions of people who are not now taking warfarin but who would benefit from it.
Warfarin, brand name Coumadin, is a powerful medicine that saves hundreds of thousands of lives every year. It works by “thinning” the blood and preventing clots that would otherwise cause strokes, heart attacks, or other blood clotting disease. Every year as many as two million Americans start taking warfarin and at any given time there are four or five million on the medicine.
The amount of warfarin required for someone to reach their target INR, the measure of the effectiveness of warfarin, varies as much as forty-fold from person to person. This interpersonal variation in warfarin dose requirement makes it time consuming and dangerous to identify the optimal dose for patients. Dangerous because the therapeutic window, the difference between the effective dose and the toxic dose of warfarin, is exceedingly small. The consequences of warfarin over-dosing are also severe — resulting bruising and bleeding are the second most prevalent cause of emergency room visits and are responsible for thousands of deaths every year. There are some safer, replacement drugs in development, but they are still at least three or four years away from being ready for market.
During the last decade scientists have discovered that most of the individual variation in warfarin dose requirement is due to genetics or variation in the DNA of individual patients. This variation, for which genetic tests are now available at the initiation of warfarin therapy, occurs at two sites on the DNA. The most important, known as CYP2C9, controls the levels of the enzyme that’s responsible for the breakdown and elimination of warfarin. Approximately 35% of the population have variant forms of this enzyme that slow down the elimination of warfarin from the system. Instead of a person reaching their warfarin and INR steady state in four or five days, it can take two weeks or more. Genetic testing is the only reliable way to determine when steady state is reached.
The second most important site of genetic variation affecting warfarin maintenance dose is the vitamin K receptor (VKORC1), the site of action of warfarin. This makes sense as it is well known that vitamin K intake affects the action of warfarin. Genetic variation is common at this site. Ninety percent of Asian-Americans have the "low-dose" variation: meaning they required a lower dose of warfarin, while most African-Americans have the "high-dose" variation requiring more drug to get adequately anticoagulated. Patients of European descent fall somewhere in the middle.
When people have DNA testing there are now computer programs that take into account their genetics, age, sex, weight and other factors, such as amiodarone or other medicines they may be taking to calculate their warfarin dose. This calculated dose is many times more accurate than the dose determined without the DNA testing.
Patients need to be proactive in obtaining this testing. Adoption of the testing by doctors and anticoagulation clinics is slow, despite endorsement by leading scientists, the FDA, and patients who have had the testing and credit it with saving them from the dire consequences of a warfarin overdose. Additionally, uptake has been slow because of the inherent conservatism of the medical establishment and lack-luster interest from pharmaceutical manufacturers.
Widespread adoption of DNA testing to predict warfarin dose will cut down on doctor and emergency room visits and save thousands of lives. A recent Brookings/American Enterprise Institute study estimates that routine use of DNA testing would save the healthcare system as much as $2 Billion per year. It will also help make warfarin therapy more accessible to the millions of people who are not now taking warfarin but who would benefit from it.
Monday, November 10, 2008
DNA & Godfather of Soul
The Godfather of Soul is also a father many times over. In addition to six children of record, three additional children have now been proven to have been fathered by the late soul singer, James Brown. About a dozen DNA tests have been performed since he died in December 2006 of heart failure at the age of 73. Some people have been ruled out as Brown's children, while other tests are still pending.
The emerging offspring are adding even more twists to the legal squabbling that emerged after the Sex Machine's death. The estate disputes between the singer's children already involves as many as two dozen lawyers.
The emerging offspring are adding even more twists to the legal squabbling that emerged after the Sex Machine's death. The estate disputes between the singer's children already involves as many as two dozen lawyers.
Friday, November 7, 2008
DID YOU KNOW?
It takes about eight hours for one of your cells to completely copy its DNA.
You could fit one million threads of DNA across the period at the end of this sentence.
If you were to start reciting the order of the ATCGs in your DNA tomorrow morning, at a rate of 100 each minute, 57 years would pass before you reached the end (provided that you did not stop to eat, drink, sleep, use the bathroom etc.)
Our genes are remarkably similar to those of other life forms. For example, we share 98% of our genes with chimpanzees, 90% with mice, 85% with zebra fish, 21% with worms, and 7% with a simple bacterium such as E. coli.
You could fit one million threads of DNA across the period at the end of this sentence.
If you were to start reciting the order of the ATCGs in your DNA tomorrow morning, at a rate of 100 each minute, 57 years would pass before you reached the end (provided that you did not stop to eat, drink, sleep, use the bathroom etc.)
Our genes are remarkably similar to those of other life forms. For example, we share 98% of our genes with chimpanzees, 90% with mice, 85% with zebra fish, 21% with worms, and 7% with a simple bacterium such as E. coli.
Tuesday, November 4, 2008
Friday, October 31, 2008
Mitochondrial DNA Tests—What Else Can They Reveal?
Mitochondrial DNA (mtDNA) testing is now commonly being used to trace female ancestry. MtDNA is passed only from a mother to her children so it gives us the unique ability to glance back in time at our female lineage; some people even use this test to confirm a suspected common female ancestor such as a great-great grandmother.
When genetic scientists examine mtDNA; they compare two portions called hypervariable region I and II to an agreed upon reference set called the Cambridge Reference Sequence. Everyone's DNA is almost identical in this portion; however, the differences are used to place you in one of 33 major “haplogroups” popularly called "clans." If you are in the same clan, you share a common female ancestor. There have been different maternal lines in existence in human
lines in existence in human history, history, but these are the only lines that can be found in existence today.
Typically a genetic testing lab will send you a report that shows how your DNA varies from the Cambridge Reference Sequence, your haplogroup designation, information about where and when your haplogroup originated, and where it exists today. Genelex offers the most in-depth haplogroup report available, but there is more information you can find if you are willing to dig a little deeper. For instance, if you happen to be in one of the haplogroups of Eurasion origins, you can read The Seven Daughters of Eve by Bryan Sykes who tells a story of what life was probably like for the original women who started the Eurasian lines.
Interested in finding your genetic cousins? If you go to www.mitosearch.org; you can enter in your mtDNA results to find genetic matches; people with an identical mtDNA signature are related to you in the more recent past. If you are interested in finding people in the same haplogroup, you can do a halpogroup search to find other members of your “clan.” Keep in mind that for haplogroup matches, your common ancestor may have walked the earth over 10,000 years ago or more.
To find out more about Ancestry DNA Testing visit:
http://www.healthanddna.com/ancestry-dna-testing/dna-testing.html
When genetic scientists examine mtDNA; they compare two portions called hypervariable region I and II to an agreed upon reference set called the Cambridge Reference Sequence. Everyone's DNA is almost identical in this portion; however, the differences are used to place you in one of 33 major “haplogroups” popularly called "clans." If you are in the same clan, you share a common female ancestor. There have been different maternal lines in existence in human
lines in existence in human history, history, but these are the only lines that can be found in existence today.
Typically a genetic testing lab will send you a report that shows how your DNA varies from the Cambridge Reference Sequence, your haplogroup designation, information about where and when your haplogroup originated, and where it exists today. Genelex offers the most in-depth haplogroup report available, but there is more information you can find if you are willing to dig a little deeper. For instance, if you happen to be in one of the haplogroups of Eurasion origins, you can read The Seven Daughters of Eve by Bryan Sykes who tells a story of what life was probably like for the original women who started the Eurasian lines.
Interested in finding your genetic cousins? If you go to www.mitosearch.org; you can enter in your mtDNA results to find genetic matches; people with an identical mtDNA signature are related to you in the more recent past. If you are interested in finding people in the same haplogroup, you can do a halpogroup search to find other members of your “clan.” Keep in mind that for haplogroup matches, your common ancestor may have walked the earth over 10,000 years ago or more.
To find out more about Ancestry DNA Testing visit:
http://www.healthanddna.com/ancestry-dna-testing/dna-testing.html
Wednesday, October 29, 2008
BREAST CANCER PATIENTS TAKE DNA TEST
Nearly one third of breast cancer patients prescribed tamoxifen currently fail treatment. According to the National Foundation for Cancer Research (NFCR), this failure rate can be reduced to less than ten percent, saving 20,000 lives each year, by having patients take a simple DNA test and properly managing their medications.
Recent research shows that tamoxifen has to be activated into endoxifen by the liver enzyme CYP2D6. Endoxifen is the medicine that prevents the recurrence of estrogen receptive positive cancers.
About ten percent of breast cancer patients prescribed tamoxifen are missing CYP2D6 because of their DNA, and will fail tamoxifen treatment. “Patients want to know that tamoxifen will definitely benefit them, before committing to take it for five years. DNA testing offers them the reassurance that their tamoxifen is effective," stated Dr. Michael Benjamin, oncologist and editor of the medical news website, InteractMD.com
Breast cancer patients can also fail tamoxifen treatment by unknowingly taking other prescription drugs, herbals preparations, or over-the-counter medicines that interfere with CYP2D6 activity. Many classes of drugs, including anti-depressants, prevent CYP2D6 from converting tamoxifen into endoxifen. That’s why Genelex includes password-protected access to their GeneMedRx software program with each test. Patients enter all of the drugs they take and produce a report to learn if any of the drugs they take might be defeating their endoxifen treatment.
“Patients and physicians need to be aware that DNA testing for tamoxifen effectiveness is available now. There is typically a 10-year gap between research and application in the clinical setting. We need to shorten that time when people’s lives are at stake- as they are with tamoxifen,” stated Genelex founder and CEO Howard Coleman.
For more information about the CYP2D6 DNA test, visit Genelex at http://www.healthanddna.com/. Genelex donates a portion of all tests purchased to the National Foundation for Cancer Research.
Recent research shows that tamoxifen has to be activated into endoxifen by the liver enzyme CYP2D6. Endoxifen is the medicine that prevents the recurrence of estrogen receptive positive cancers.
About ten percent of breast cancer patients prescribed tamoxifen are missing CYP2D6 because of their DNA, and will fail tamoxifen treatment. “Patients want to know that tamoxifen will definitely benefit them, before committing to take it for five years. DNA testing offers them the reassurance that their tamoxifen is effective," stated Dr. Michael Benjamin, oncologist and editor of the medical news website, InteractMD.com
Breast cancer patients can also fail tamoxifen treatment by unknowingly taking other prescription drugs, herbals preparations, or over-the-counter medicines that interfere with CYP2D6 activity. Many classes of drugs, including anti-depressants, prevent CYP2D6 from converting tamoxifen into endoxifen. That’s why Genelex includes password-protected access to their GeneMedRx software program with each test. Patients enter all of the drugs they take and produce a report to learn if any of the drugs they take might be defeating their endoxifen treatment.
“Patients and physicians need to be aware that DNA testing for tamoxifen effectiveness is available now. There is typically a 10-year gap between research and application in the clinical setting. We need to shorten that time when people’s lives are at stake- as they are with tamoxifen,” stated Genelex founder and CEO Howard Coleman.
For more information about the CYP2D6 DNA test, visit Genelex at http://www.healthanddna.com/. Genelex donates a portion of all tests purchased to the National Foundation for Cancer Research.
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