Cystic Fibrosis Might Be Deadlier for Hispanics, Study Suggests

Genetic differences may thwart response to latest treatments, researchers say

By Mary Elizabeth Dallas

Tuesday, June 30, 2015

TUESDAY, June 30, 2015 (HealthDay News) -- Cystic fibrosis is deadlier for Hispanic patients than others, and genetic differences may make Hispanics less likely to benefit from new treatments for the disease, researchers report.

"We need to ask if the care model for patients with [cystic fibrosis] is working for this minority group," study author Dr. MyMy Buu, an instructor in pediatric pulmonary medicine at Stanford University School of Medicine in Palo Alto, Calif., said in a university news release. "We want to make sure that what we are doing is not inadvertently causing disparities."

The findings reflect an urgent need to identify the factors that contribute to this health disparity, the researchers noted.

"This will be crucial to develop treatment regimens that guarantee that all children with [cystic fibrosis] can benefit from early diagnosis and the novel treatments being introduced," study co-senior author, Dr. Carlos Milla, director of the Stanford Cystic Fibrosis Center, said in the news release.

Cystic fibrosis is a genetic disease that causes serious lung and digestive problems. Using patient data from the patient registry of the Cystic Fibrosis Foundation, researchers examined all California residents diagnosed with the disease as children between 1991 and 2010. Overall, more than 1,700 patients were included in the study; 28 percent were Hispanic.

During the study, 9 percent of the Hispanic patients died, compared to slightly more than 3 percent of non-Hispanic patients, according to the study published online recently in the journal Chest. The risk for death was nearly three times greater for Hispanic patients, the researchers noted.

Some plausible explanations were ruled out, including later diagnosis and less access to health care.

The only key differences the researchers found between the two groups was that Hispanics developed cystic fibrosis complications earlier and tended to have less common mutations in their disease-causing gene, known as the CFTR gene.

"We are moving in the direction of gene mutation-directed therapy," Buu said. "The [cystic fibrosis] research community is trying to understand these mutations, and those that are most frequent in the [cystic fibrosis] population are being studied first."

In the past, most cystic fibrosis patients died during childhood, but dramatically improved treatments have improved survival rates. More than half of all cystic fibrosis patients in the United States now live beyond 40, the researchers said.

When it comes to current treatments, however, Hispanic patients with rare mutations are at a disadvantage. "It will take longer to get to them, but there are efforts to understand all the mutations of the CFTR gene," said Buu. "We hope to create awareness of this disparity, and we hope that it is modifiable."

SOURCE: Stanford University School of Medicine, news release, June 24, 2015

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