Much of the promise of future improvements in medical research is premised on better understanding of genetics and how certain genes lead to greater disease risks or react to certain treatments. 

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So it’s big news when a study in the New England Journal of Medicine found that African Americans were more likely to be diagnosed as at risk for a heart condition because of a flawed understanding of genetic traits. 

Certain mutations that black people were more likely to carry were mistakenly linked to hypertrophic cardiomyopathy, a relatively rare condition that affects only about 1 in 500 Americans. Later research that included an examination of a larger population of African Americans later determined the mutation had nothing to do with the disease. 

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The study suggested that doctors’ understanding of genetic traits are often based on research that does not include enough members of racial and ethnic minority groups. The sample size simply is not big enough to develop as comprehensive an understanding of common genetic traits in African Americans as for whites. 

Misdiagnoses lead to psychological distress for the patient receiving the false diagnosis as well as unnecessary medical expenses. A false diagnosis for a serious heart condition might lead to an expensive, invasive operation, including a chest implant. 

The good news, going forward, is that the cost of genetic research has become much cheaper. 

“The cost of gene sequencing is now tiny, so I think we have the luxury to be able to get good representative control samples of our population, to make sure our studies are diversely controlled,” Dr. Isaac S. Kohane, one of the study authors, told the New York Times. 

Genetic testing can help identify people more likely to get certain diseases, and help them take preventative measures to reduce their risk. Women identified as at a high risk of breast cancer may undergo a mastectomy, for instance. 

However, a recent study found that a significant percentage of health insurers refuse to cover genetic testing, a policy that the National Women’s Law Center, which conducted the research, said disproportionately harms women.