Using Genetic Technologies to Reduce Health Disparities

Genetics play an important role in the occurrence of common diseases, and advances in genetic technologies have a great potential to be used to advance treatments, especially through personalized medicine. However, there are concerns that disadvantaged groups do not have access to these advances, and that treatments growing from the new technologies might not be generalizable to minorities if research continues to include mainly non-Hispanic white subjects.

Writing in Health Affairs, Caren E. Smith, MS, DVM, of Tufts University, and colleagues note that existing disparities will only widen without efforts to integrate strategies to expand genetic research and make genetic technologies universally accessible.

For example, the Precision Medicine Initiative launched by President Barack Obama in 2015 will collect and analyze information from a million volunteers to generate data about how genetics, environment, and lifestyle contribute to disease. The authors cite the importance of the advancing study of epigenetics, which describes chemical modifications to DNA that may alter gene expression without altering the DNA sequence itself, and is in contrast to genetic mutations, which are fixed throughout a lifetime. Epigenetic changes can be affected by behaviors such as smoking, diet, and physical activity. The authors explain that we must guard against new genetic technologies, such as next-generation sequencing, being implemented in ways that perpetuate and possibly widen health disparities.

“Despite the impressive leaps forward in genetics, not all groups are positioned to benefit form discoveries in the field,” the authors wrote.

For example, breast cancer and chronic kidney disease are 2 common conditions for which knowledge about genetics have grown tremendously but for which racial and ethnic health disparities persist. People with non-European ancestries are underrepresented in genetic databases, limiting the ability to apply genetic knowledge to reduce disease in these groups.

The authors cite as an example of the issue hereditary breast cancer, caused by mutations in the BRCA1 or BRCA2 genes, which has led to intensive cancer screening and risk-reducing surgeries in women with the gene mutation. These efforts have reduced cancer and mortality in women who undergo the surgery. But African American and Hispanic women are much less likely than white women to get genetic counseling or testing for breast cancer. One-third of African American women at high risk for hereditary breast cancer have not been referred for counseling and testing.

The authors noted that with third-party insurers and Medicare and Medicaid paying for BRCA mutation testing, affordability does not appear to be the issue; rather the issue is social and educational. In minority communities, low awareness of familial cancer risk and social and cultural beliefs contribute to disparities in the use of genetic services.

Studies have also shown that compared with non-Hispanic white women, non-Hispanic black women were almost twice as likely to be diagnosed with triple negative tumors, which are less amenable to treatment and associated with a worse prognosis. Data suggest that women who have not breast-fed infants are at increased risk of such tumors and that promotion of lactation may be effective in reducing these kinds of cancers.

Research into epigenetic markers may be particularly informative about minority groups that are exposed to environmental risk, such as food deserts, stress, pollution, and unsafe streets. But small samples of tumors from minority women available for study and poor follow-up not only runs the risk or widening disparities on an increasing scale, it limits translation of genetic knowledge into clinical benefit for all individuals, the authors wrote. They recommend greater support for a more targeted approach, with minority-focused research, community-based participatory research, and studies of gene-environment interaction, as well as education.