...
EgyptSearch Forums Post New Topic  New Poll  Post A Reply
my profile | directory login | register | search | faq | forum home

  next oldest topic   next newest topic
» EgyptSearch Forums » Egyptology » OT: WHAT COLOR IS DNA

 - UBBFriend: Email this page to someone!    
Author Topic: OT: WHAT COLOR IS DNA
SEEKING
Member
Member # 10105

Rate Member
Icon 1 posted      Profile for SEEKING     Send New Private Message       Edit/Delete Post   Reply With Quote 
What color is DNA?

The Molecular Reinscription of Race in Medicine and Forensic Science

Speaker: Troy Duster, PhD
New York University

Genomics research is quietly re-incorporating some of the old racial concepts it initially tried to overturn.
Instead of patient-specific drugs, some pharmaceutical companies are now marketing race-specific drugs.
When studying racial differences, biologists must be especially cautious of leaping to conclusions.


What color is DNA?

In the summer of 2000, President Clinton held a press conference at the White House to announce the completion of the human genome sequence, an event whose importance depends on what your definition of the word "completion" is. But whether the project was really done at that point or a few years later, scientists at least appeared to agree on one of the fundamental findings: the genome is racially neutral.

Indeed, prominent researchers seemed to make a special effort to pronounce race a social concept, not a biological one, an argument bolstered by the 99.99% identity between the genomes of any two individuals' genomes. The genome sequence was also supposed to undergird a new form of individualized medicine, called pharmacogenomics, in which therapies are tailored to specific patients. Meanwhile, forensic DNA fingerprinting would get a boost from the more robust statistical base of a fully sequenced genome.

Old racial concepts may be creeping back into genomics.

Racial categorization of patients in a clinic, or suspects in a lineup, was supposed to go the way of the poll tax. With the old categories obsolete, the hope was that our biology could be judged not by the color of our skin, but by the content of our chromosomes.

As Troy Duster of New York University pointed out in his presentation, this idealistic gloss covers a much more complicated reality. Rather than being relegated to the biohazard bag, racial concepts could be creeping back into the core of genomics, a development with potentially troubling and far-reaching consequences.

Ask your doctor about segregation

The idea of a race-neutral genome is hard to square with developments like BiDil (hydralazine/ isosorbide) . Launched by the pharmaceutical company Nitromed at the beginning of 2005, BiDil is a treatment for heart disease—but only for black people. If DNA is colorblind and medicine is becoming truly individualized, why are patients still being separated on the basis of race?

When Nitromed tested BiDil in patients, the large-scale clinical trial showed the drug had no significant efficacy against heart disease. Based on those results, the U.S. Food and Drug Administration (FDA) denied Nitromed's approval application. Rather than going back to the drawing board, Nitromed returned to the data-mining software, and quickly discovered that a subset of patients—the African Americans in the trial—received some benefit from BiDil. The new interpretation persuaded the FDA to approve the drug for use in blacks.

BiDil targets nitric oxide metabolism, and Nitromed researchers now hypothesize that this process may differ slightly in people of African descent, making the drug more potent in that population. African Americans under the age of 65 suffer dramatically higher rates of heart disease than Caucasian Americans in the same age group. Perhaps some of the same biology that underlies the disparity in heart disease rates also underlies the disparity in BiDil response. In other words, maybe BiDil needs to be racialized because the biology of heart disease is racialized.

The FDA and Nitromed investors found that argument convincing, but Duster is skeptical. One problem is that the heart disease statistics vary internationally. Blacks outside the U.S. have heart disease at about the same rates as their white compatriots, strongly suggesting that the epidemiology is driven by culture, not biology. Furthermore, the heart disease disparity in the U.S. equalizes in people over 65, the age group that accounts for the overwhelming majority of the disease.

Non-Mendelian minorities

Unfortunately, public discussions of race tend to be as noisy as artillery battles, but with less nuance. The debate over racial genetics is no exception. Duster advocates reframing the question, so that instead of asking whether racial concepts are inherently good or bad, researchers should ask, "Under what conditions should we use race?"

Under what conditions should biology use racial concepts?

In the case of BiDil, for example, the results in black patients in the original trial could form the basis of a testable hypothesis, rather than a race-based prescription label. "The question for me is, is it nitric oxide deficiency? If this is the case it should be available to all those who have this deficiency; it should not be racialized. What I am opposed to ... is the notion that we can [get] a molecular understanding of race with this kind of research," says Duster.

Some scientists argue that race can be a surrogate marker for medically relevant traits. Sickle-cell disease, for example, correlates with black skin. However, as geneticists have known since the early 1900s, gene linkage is often imprecise, especially between complex genotypes. Even the single point mutation of the sickle-cell trait sometimes occurs in white patients. Diseases that involve multiple genes interacting with the environment are probably impossible to link reliably to racial markers.

The social context of race exacerbates the problem by preventing good experimental controls. Traditionally, social scientists control measurable factors such as income and social class, then look for differences between races. Some biologists skip the next link in the causal chain, assuming that class-controlled racial differences can only be explained by biology. "I think it's a mistake to leap from the outcome data back to genotype," says Duster.

That leap skips a vast territory of overt and covert racial differences that are entirely environmental, but not connected to income or class. "If you get stopped [by police] eight more times than whites on average, if you get followed around at Neiman-Marcus, if you get fewer bank loans from the Philadelphia banks ... you might develop hypertension, " says Duster.

Opinions of difference

When did genomics shift its emphasis from our similarities to our differences? Duster pinpoints a major transition in 1999, when prominent researchers began promoting the idea of cataloging racial polymorphisms across the genome. The initial effort, led by the public-private SNP Consortium, focused on mapping thousands of single nucleotide polymorphisms (SNPs) between individual genomes. When scientists found that these single-base differences tend to cluster together, the project evolved into the haplotype map, or HapMap.

Police are now developing racial profiles from DNA samples.

More recently, several pilot projects have shown, unsurprisingly, that certain haplotypes tend to be more common in particular races. Police forces are now testing SNP-based technologies to develop racial profiles from DNA samples at crime scenes. While that could lead to more solved crimes, it could also amplify the egregious racial disparities in everything from traffic stops to incarceration.

According to Duster, most of these recent developments in racialized genomics have occurred out of public sight. Only a hopeless idealist could expect genomics to solve racism completely, but with more open discussion of the technology's implications, it might at least avoid becoming part of the problem.

http://www.nyas. org/ebriefreps/ main.asp? intSubsectionID= 3580

Posts: 391 | Registered: Jan 2006  |  IP: Logged | Report this post to a Moderator
Supercar
Member
Member # 6477

Icon 1 posted      Profile for Supercar         Edit/Delete Post   Reply With Quote 
Much of this relates to what has already been spelt out in the following discussions:

Clyde Winters, you still believe biological race exists?

Races Exist: Global variation in copy number in the human genome

...and from an old posting, this may well relate to this subject:


quote:


TITLE: The Race to Prescribe
SOURCE: Science News 167 no16 247-8 Ap 16 2005

BEN HARDER


Drug for African Americans may debut amid debate


The second in a two-part series on race, biology, and medicine

Most modern medical research into race or ethnicity focuses on the disturbingly long list of health disparities among different groups. For example, compared with whites, blacks are 30 percent more likely to die of heart disease at any given age and 40 percent more likely to die of a stroke. Overall, blacks have an average life expectancy that's 5 years shorter than that of whites.

Has more to do with discrepencies in access to medical coverage, due to the general socio-economic disparities.

Studies: Blacks Have Less Access to Health Care Than Whites
Three major health studies published today show that African Americans continue to have less access to operations, tests, medications and other life-saving treatments than whites. The studies find that Black people remain much less likely to undergo heart bypasses, appendectomies and other common procedures. They receive fewer mammograms and basic tests and drugs for heart disease and diabetes.”
- Democracynow.org


"Black Americans still get far fewer operations, tests, medications and other life-saving treatments than whites, despite years of efforts to erase racial disparities in health care and help African Americans live equally long and healthy lives, according to three major studies being published today.

Blacks' health care has started to catch up to whites' in some ways, but blacks remain much less likely to undergo heart bypasses, appendectomies and other common procedures. They receive fewer mammograms and basic tests and drugs for heart disease and diabetes, and they have fallen even further behind whites in controlling those two major killers, according to the first attempts to measure the last decade's efforts to improve equality of care.

Together, the research paints a discouraging picture of the nation's progress in closing the gap for one of the fundamental factors that affect well-being -- health care -- during a period when blacks have made progress in areas such as income and education."
- Washington Post

 -

...and mentioned in more detail, here!


quote:

Cautious voices also warn that the wrong precedent by FDA in its handling of BiDil could contribute to, rather than reduce, health disparities between blacks and whites.

A possibility that cannot be ruled out!


quote:
"There's only one human race," says cardiologist Anne L. Taylor of the University of Minnesota in Minneapolis. "But within that race, there are subpopulations that have small variations. Those variations can have an impact, and we have to explore them."
True. While the variations among populations are acknowledged, there is only one human race. These variations that make up about .01% of the overall variation among humans, are best dealt with genetically, as rationalized later on in this article, rather than unscientific and even ambiguous social constructs.


quote:
But while the newer medicines were more effective than the older compounds in cutting heart failure deaths in whites, the disease remained a stubbornly persistent killer in blacks. Today, among 45-to 64-year-olds, blacks are nearly twice as likely as whites to have heart failure and are 2.5 times as likely to die from it...

Several studies have suggested that active nitric oxide tends to be less abundant in blacks than in whites. That could partially explain why heart failure is a more serious disease among the former group, says Taylor.

I think it has more to do with socio-economic disparities than the stated reason herein.


quote:
In 1999, University of Minnesota researchers reexamined the earlier data. They found that black people with heart failure had tended to benefit from the combination, while most whites hadn't.
What about people of mixed various ethnic backgroups, how predictable will they respond? Notice how it is said "most", which implies "not all". So again, genetic determination is the best approach, rather than imprecise social constructs (implying clearly defined biological boundaries) based on outer physical appearances, which can be misleading genetically speaking.


quote:
"Many differences in drug response associated with race or ethnicity are due to environmental [factors such as diet] rather than population genetic differences," they say. "In the case of BiDil, it is not currently known whether it works differently in African Americans and European Americans because of genetics, environment, or both."
Likely so!


quote:
Genetic traits do appear to underlie some differences in disease susceptibility and response to therapies. For example, researchers have noted for years that because of differences in enzyme activity, people of Asian descent metabolize cholesterol-lowering statin drugs more slowly than other people do. As a result, some studies suggest, Asians are more susceptible to side effects at a given dose of statins. FDA recently advised physicians not to administer the highest allowed dose of one such drug, rosuvastatin (Crestor), to people of Asian ancestry.
No reason to believe why this wouldn't be a case [with emphasis on the highlighted phrase]. It just becomes a problem when mere social contructs are used to pre-determine such genetic traits, as mentioned above, based on superficial outer physical appearances.

Case in point, is the following:


quote:
The biological mechanism remains opaque in other instances where medications have differential effects in various ethnic groups.

"Our understanding of race and drug response is at best very superficial," says Lesko....

Defining groups by the external cues used to indicate race is far from ideal, Lesko says.

quote:
Unearthing specific segments of DNA that explain individuals' differences in drug response would be ideal for patients, Clayton says, but economics might be working in just the opposite direction.
Now we are talking.

But...


quote:
Testing patients' genetic differences is more costly and time-consuming than is interviewing them about their ancestry. Furthermore, Lesko says, there's no point in approving a drug for genetics-based clinical use unless a test for the relevant genetic trait is widely available to doctors.
A chance most companies, being profit driven, don't want to take!

And case in point...

quote:
FDA has released guidelines on how pharmaceutical companies can develop such diagnostics, and last December, it approved the first commercial screening test for a gene that affects drug metabolism. That test can guide physicians in the dosages that they prescribe for certain antidepressants, antipsychotics, and chemotherapy drugs. However, relatively few drug companies see potential for profit from such products, Lesko says.

What's more, pharmaceutical firms may find it better for business to delve no deeper than racial differences.

Lesko says that information identifying which patients won't benefit from a drug might narrow, rather than expand, the number of people for whom the drug can be recommended.

quote:
On the other hand, he adds, both drug companies and patients would benefit from genetic tests that flag people--of any race--most likely to suffer drug-related side effects.
The way to go!


quote:
Given today's concern over drug safety, that improvement in treatment precision could make a difference in patients' lives and on companies' bottom lines, ultimately advancing the prospect of individualized medicine. One day, people may be treated not by the color of their skin but by the content of their genome.
The sooner that day comes, the better off we would be!

Initially posted here: Interesting article on race-based medicine...


Finally, from the intro article of this very thread:

Some scientists argue that race can be a surrogate marker for medically relevant traits. Sickle-cell disease, for example, correlates with black skin. However, as geneticists have known since the early 1900s, gene linkage is often imprecise, especially between complex genotypes. Even the single point mutation of the sickle-cell trait sometimes occurs in white patients. Diseases that involve multiple genes interacting with the environment are probably impossible to link reliably to racial markers.

^Hence, understanding bio-anthropology is the key.

'Nuff said!

Posts: 5964 | Registered: Jan 2005  |  IP: Logged | Report this post to a Moderator
yazid904
Member
Member # 7708

Rate Member
Icon 1 posted      Profile for yazid904     Send New Private Message       Edit/Delete Post   Reply With Quote 
Race based medicine, despite being a lie and an attempt to deceive, has always been practiced by the majority meaning when both blacks and whites (North American scenario) have the same symptoms, diagnoses and outcome, it is the white people who getter the better treatment or surgical options. That is race based medicine on that level!

The next level of 'race based medicine' is drugs for specific ethnicities but black are only recently been the target of research. Black were often left out or never treated (Tuskeegee experiment)! Tay-Sacks pertain to many with Jewish ethnicity but they never refer to that as 'race based' even though that group only suffers from that condition whilst hypertension runs through all ethnicities so it is not, in my opinion, race based medicine.

Posts: 1290 | From: usa | Registered: May 2005  |  IP: Logged | Report this post to a Moderator
   

Quick Reply
Message:

HTML is not enabled.
UBB Code™ is enabled.

Instant Graemlins
   


Post New Topic  New Poll  Post A Reply Close Topic   Feature Topic   Move Topic   Delete Topic next oldest topic   next newest topic
 - Printer-friendly view of this topic
Hop To:


Contact Us | EgyptSearch!

(c) 2015 EgyptSearch.com

Powered by UBB.classic™ 6.7.3