Study links asthma gene to ethnicity or race

A study supported by the National Heart, Lung, and Blood Institute (NHLBI) suggests that the importance of certain genes linked to asthma susceptibility or asthma-associated traits may vary by race or ethnicity.

In the study published in the April issue of Nature Genetics, researchers examined data on 380 individuals with asthma — 117 African Americans, 215 caucasians, and 48 hispanics. During the course of the study, the researchers located six previously unidentified chromosomal regions thought to be linked to asthma susceptibility genes. Five additional regions are thought to be linked to asthma-associated traits, such as bronchial hyper-responsivity.

Researchers found that 10 of the 11 chromosomal regions were specific to a single racial or ethnic group. That suggests "that the relative importance of specific asthma-susceptibility genes and the effects of environmental exposure may vary by race or ethnicity," according to NHLBI.

Asthma is more common among African Americans than whites (6.1% compared with 5%). Among hispanics, the prevalence of asthma ranges widely, from a high of 11.2% for Puerto Rican children in New York City to a low of 2.7% among Mexican American children in the Southwest, according to the NHLBI. Hospitalization and death rates from asthma are almost three times greater for African Americans than for whites.