Story URL: http://news.medill.northwestern.edu/chicago/news.aspx?id=99417
Story Retrieval Date: 5/26/2013 2:24:03 AM CST
A small, fist-sized organ has been one of the biggest causes of death in the African-American community, and for the first time, researchers have identified a genetic reason.
After studying the genomes of 190 African-Americans with FSGS, a form of kidney disease that leads to kidney failure in 10 years for more than half of those who have it, and 222 African-Americans without FSGS, researchers concluded that blacks carry variations of the MHY9 gene, which is strongly linked with kidney disease.
The study, by Johns Hopkins with the National Institutes of Health, notes that 60 percent of African-Americans carry variations of the MHY9 gene, in contrast to 4 percent of whites. Dr. George Bakris, a professor of medicine at the University of Chicago and director its Hypertension Center, says this study could be the explanation doctors have been searching for.
“If you take 100 African-Americans, all of whom have mild kidney disease, the probability that an African-American will go into dialysis in comparison to a white is six times higher. There’s got to be something driving that; it’s not just blood pressure,” he said.
“We’ve been looking for candidate genes for a number of years to help identify those more at risk, and this is the first of what I think will be many more studies."
Nonetheless, before even considering gene therapy to tackle the chronic kidney disease disparity, Chicago-based physicians believe that education and prevention are needed.
“This is an issue that starts with the primary care physician,” said Dr. Julio Vijil, an assistant professor of medicine at the University of Chicago. “I think if there’s any benefit from this knowledge, it’s to make primary care physicians more aware that these groups are more at risk and you need to be very vigilant about looking for the common causes of kidney disease.”
Dr. Bakris agreed, ssaying the possibility of additional prevention measures based on genetic markers is unlikely, and that the medical community should respond by first looking to the leading causes of the disease: diabetes and hypertension.
“Look at the percentage of people who are black who have their blood pressure controlled compared to whites,” Dr. Bakris said. “Whites at goal[120/80], it’s about 32 percent, 34 percent; blacks at goal [120/80] it’s about 11 percent. So we can do a lot better in terms of achieving blood pressure goal, that’s number one. Number two, in addition to that, the standard things – better glucose control, better lipid control, reduction in diabetes, all of those things play a factor.”
Of course, one of the other issues fueling the large number of blacks with kidney disease is a lack of access to a primary care physician, both Vijil and Bakris noted.
“If you have a physician, the job of the physician is to educate the patient about possible risks, and whether the patient follows the rules or not is up to them,” Bakris said. “But nevertheless, if they’re not educated, then it’s a non-issue, there’s nothing to follow. I think in high-risk groups there should be some mechanism to ensure that those people have a primary care physician, independent of insurance.”
Vijil sees the lack of access a concern that trumps genetic research at this stage. “Down the road, maybe something can be done about the gene problem, but I don’t think we’re anywhere near the gene therapy. Time is better spent on preventative care and identification of people with early stage kidney disease.”