NEW YORK – A recent study led by researchers at Mount Sinai in New York found that informing patients of genetic testing results immediately, using members of their community — rather than outside genetic counselors — led to significant lifestyle changes.
The study, published in JAMA Network Open earlier this month, assessed the effects of telling patients with risk variants in the apolipoprotein L1 (APOL1) gene the results of genetic testing. High-risk variants of the genotype are common in people with African ancestry and indicate a higher risk of kidney failure and hypertension.
Girish Nadkarni, a professor of medicine at Mount Sinai's Icahn School of Medicine and the study's first author, said that while there are a lot of systemic factors that lead to the disproportionate rate of kidney disease in people of color, the APOL1 gene leads to a "fivefold increase in risk."
Regardless of what the test is for, the results of the study suggest that using community resources to explain the results of any genetic test to patients are beneficial to them.
According to the JAMA paper, blood pressure control can reduce kidney function deterioration, but "people of African ancestry have the highest age-adjusted prevalence of hypertension and the lowest rates of blood pressure control." In addition, kidney function tests can help clinicians risk-stratify patients, but they "are underused among patients at high risk of [chronic kidney disease], especially patients of African ancestry," the researchers wrote.
The study's aim was to find out whether testing patients for APOL1 would affect clinical care processes, such as kidney disease screening, and improve outcomes, the researchers wrote. Nadkarni noted that there has been "a lot of interest" around the gene, making it a "prime candidate" to be the subject of the study.
In the Genetic testing to Understand and Address Renal Disease Disparities (GUARDD) study, 2,050 African American patients with hypertension, but without existing chronic kidney disease, from two health systems in New York were assigned to an interventional or delayed group, which dictated when they would receive genetic testing results. The interventional group and their clinicians received results immediately, while delayed group patients received their results after 12 months.
The study, which monitored patients between 2014 and 2018, found that patients in the interventional group had increased improvement in blood pressure, increased the frequency of urine testing for kidney function, and had more lifestyle changes, Nadkarni said. Patients in this group also reported that they were "happy to get tested" and would get tested again, he said.
Although the average blood pressure for all patients dropped three months after enrollment in the study, high-risk APOL1 patients saw a greater drop in blood pressure than those with low-risk APOL1 variants and those who had not received results.
A key component of the study, said Carol Horowitz, a professor of population health science and policy at Mount Sinai and the study's senior author, was that patients received their results from trained laypersons instead of genetic counselors. Having clinical research coordinators who belonged to the same community provide results in person to patients with high-risk APOL1 genotypes ensured that patients understood the information being given. Coordinators would ask patients to repeat the explanation in the patients' own words and would repeat or reframe the explanation until they understood, the researchers wrote.
The study was performed in collaboration with the Genomics Stakeholder Board, which included local patients, clinicians, advocates, and health system leaders. In working with the board, the researchers "tried to figure out what was most important to patients" when genetic testing results were being communicated, Nadkarni said. What they found, he added, was that patients wanted "the ability to know their own risk so something can be done."
There are a variety of factors that keep people of color, particularly African Americans, from utilizing genetic testing, including socioeconomic issues and distrust in the medical system, Nadkarni said, so engaging individuals that are trusted in Black communities was essential.
Minoli Perera, an associate professor of pharmacology at Northwestern University's Feinberg School of Medicine who was not involved in the study, noted that there are also disparities in which patients get referred for genetic testing, with a preference toward those who are being seen at large academic medical centers and patients with cancer.
Clinicians in other subspecialties beyond oncology, including nephrology, are significantly less likely to utilize genetic testing and might not be as familiar with it, she added. A lack of physician education is "still a big stumbling block" when it comes to getting patients genetic testing, she said.
There are also a lot of regulations and restrictions on which labs can perform which types of genetic tests, and many labs in smaller settings may not be able to meet those requirements, she said. All of these factors can contribute to minority patients not receiving genetic testing, she said.
But this study, along with other efforts and initiatives to disseminate genetic testing beyond academic medical centers, is a step in the right direction, she said. Although studies like this — ones specific to a particular ethnicity — aren't "commonplace," Perera said there's a "real importance in doing this specific work for a specific community."
It "has a direct impact," she said.
Similar studies that look at genetic testing and its effects among people of color are becoming more prevalent, however. A recent study of BRCA1/2 testing patterns among triple-negative breast cancer patients showed that African American women are facing more barriers in accessing genetic testing, while research published in the New England Journal of Medicine in 2016 showed that lack of diversity in genetic studies can result in misdiagnoses of heart disease for patients with African ancestry.
The Mount Sinai researchers are now conducting a national multicenter trial, GUARDD-US, which is enrolling 5,000 patients, including those with chronic kidney disease, Nadkarni said. It will be looking at a variety of outcomes, including clinical and psycho-behavioral factors, such as blood pressure and patient satisfaction, he added.
The study's authors are hopeful that the results from the original GUARDD study could improve access to genetic testing. The results "may support an approach of broad implementation of genetic medicine in primary care," they wrote. That implementation "will benefit racial and ethnic minority groups that have been traditionally underrepresented in both clinical trials and genetic studies."