Asthma hits African-Americans particularly hard, and the healthcare system often fails them, reports STAT.

An estimated 15.3% of black children have the disease compared with 7.1% of white children, according to the CDC. Overall, African-Americans are nearly three times as likely to die from asthma as white people.

The development of a genetic test for asthma would mark another example of the potential of precision medicine—treatments tailored to patients’ genetic profiles and unique physiological characteristics.

But it won’t be easy. Many factors besides genes and ancestry—including environmental exposures, stress, and social forces such poverty and racism—influence asthma incidence and the effectiveness of treatments.