Learning about Disparities from Genetics Data
Racial and ethnic disparities in disease incidence and outcome remain stubbornly entrenched in the US despite an abundance of biomedical advances and targeted public health interventions. This is likely due to the multifactorial nature of health disparities, where a combination of lifestyle, biological, and societal factors all act as contributors. A review article published in the Journal of Allergy and Clinical Immunology (link available here) illustrates how genetics data can not only shed light on the biological contributions to racial and ethnic health disparities, but also how this type of research can inform treatment decisions that will lead to the individualization of patient care.
The article describes disparities in asthma - African Americans and Puerto Ricans experience higher morbidity and mortality from the disease than non-Hispanic whites and Mexican Americans – and lays the groundwork for why these differences by ethnicity might exist. In brief, ancestry-linked genetic variation is associated with differences in both (a) baseline lung function, which influences asthma severity, and (b) response to asthma treatment. For example, individuals with African ancestry tend to have genetic variants that are associated with lower baseline lung function. This may help explain why African Americans, a group with high proportions of African ancestry, may experience more severe asthma than other ethnic groups. Similarly, the review also describes differences in response to treatment between African Americans and non-Hispanic whites receiving therapy for asthma. In some studies African Americans were found to be less responsive to treatment. This may result from genetic variation in the receptors targeted by the asthma treatments.
The studies highlighted in this review demonstrate the potential of genetics research to better understand and reduce health disparities. By examining genetic factors underlying disease severity and treatment responsiveness, researchers can develop more individualized treatments. As the authors’ note, this will require more in-depth study of African Americans and other racial and ethnic groups to gain a better understanding of how ancestry-linked genetic variation influences disease incidence and outcome.