Study reveals new genetic clues associated with asthma in African-descendant populations

CU Anschutz scientists discover areas of chromosomes badociated with asthma, a complex disease with striking disparities between racial / ethnic groups

In the largest study of its kind, researchers at the Anschutz Medical Campus of the University of Colorado have uncovered new clues to parts of the human genome badociated with higher asthma rates among those in the United States. African origin.

The study was published today in the journal Nature Communications.

By using new advanced technology, scientists were able to identify loci or locations on a specific chromosome that could increase the risk of asthma in people of African descent.

They also discovered four chromosomal regions generally present in Whites and Asians badociated with asthma. One of these chromosomal regions is known as the 17q12-21 region.

Despite the high incidence of asthma among people of African descent, it has always been underrepresented in the genome-wide badociation studies (GWAS) even though the African genome is the most diversified on the planet.

"In the largest GWAS of asthma ever observed in populations of African descent, we found strong evidence of badociation at four previously reported asthma loci whose discovery was based on largely on non-African populations.We also identified two new loci on chromosome 8 that could be: Michelle Daya, PhD, badistant professor in the Division of Biomedical Informatics and Personalized Medicine at the CU School of Medicine, explains the risk of asthma in populations of African descent.

According to Kathleen Barnes, PhD, lead author of the study and director of CU Anschutz's Colorado Center for Personal Medicine, people of African descent living in the Americas and elsewhere face a disproportionate burden of disability, illness and death due to to common chronic diseases such as asthma and diabetes.

Yet, the group has been little studied.

To better understand this population and its genetic impact, Barnes collaborated with the National Institutes of Health's National Institute of Heart, Blood and Lung (NHLBI) to create the "Consortium on Population Asthma." of African descent in the Americas ", or CAAPA.

They sequenced the genome of 642 people of African descent from 15 populations in North America, Central and South America, and the Caribbean, as well as Yoruba-speaking individuals and natives of the United States. Ibadan in Nigeria.

"NHLBI encourages basic research to understand the genetic contribution to the disparities of asthma among racial and ethnic groups, and CAAPA is one of our major investments in this area," said James Kiley, director of the NHLBI Division of Pulmonary Diseases. NIH.

In this latest study, researchers examined 7,009 cases of asthma and 7,645 controls.

"From this study, we can say that the 17q chromosome is important for the development of asthma, not only in populations of European or Asian origin, but also in those of the US. African origin, "said Barnes. "It's a big step forward in resolving what's happening in this place."

The researchers were able to draw these conclusions from new technologies, such as the development of the African diaspora chip in partnership with Illumina Inc., which improves the tagging and coverage of genetic variation in African descent.

"We need to understand what causes asthma in these populations," Barnes said. "We now have a better genetic foundation to continue on this path."

Daya agreed.

"Ultimately, we hope that a better understanding of the genetic risk factors for asthma in populations of African descent will lead to the development of better therapeutic interventions," he said. she said.