After studying the genetic sequences of more than 100,000 people, researchers across the country set out to uncover the root causes of inflammatory bowel disease (IBD), Crohn’s disease, and ulcerative colitis. But those studies have a stark flaw: They are based mostly on genetic data almost exclusively from individuals of European ancestry.
Now researchers at the University of Miami Miller School of Medicine are trying to change that. Maria Abreu, MD, director of the Miller School’s Crohn’s and Colitis Center, and Jacob McCauley, director of the Center for Genome Technology and Biostorage Facility, have been awarded a $2.9 million grant from the National Institutes of Health (NIH) to spend the next five years collecting and analyzing genomic data. to more than 3,000 Hispanic individuals, in order to better understand inflammatory bowel disease in this community.
Hispanics have much lower rates of IBD than people in the US or Europe, but Dr. Abreu began seeing Latin Americans develop IBD rapidly after moving to the US and she wanted to study these changes, but with very few genetic sequences. Hispanics available for the study, Dr. Abreu knew she needed to expand the pool.
Officials at the National Institutes of Health felt the same, writing in the grant announcement that there was an “urgent need” to increase the diversity of genetic sequences.
The NIH now recognizes that Hispanics and Blacks, who are a very important percentage of our country, are underrepresented in all of these studies.”
Dr. Maria Abreu, MD, director of the Crohn’s and Colitis Center at the Miller School
“More statistical power in numbers”
Dr.. Abreu and McCauley have already collected the DNA of nearly 2,000 Hispanic individuals from South Florida. The NIH grant allows them to raise an additional $3,000 for the IBD study.
Dr. McCauley says these large numbers are important. Humans share 99% of their genes, but he said, “That one percent is a lot.” If a study contains very few genetic sequences, the differences between them may be random or insignificant. More genetic sequences allow scientists to identify clearer patterns and focus on specific genes that may contribute to disease and other diseases.
“There is more statistical power in the numbers,” he said. “We have to change the process of recruiting and enrolling and letting those patients who have not been contacted in the past know about these studies, and trying to enroll them to help us with these discoveries.”
This is a far cry from the days when geneticists purposefully sought out genetic sequences from people of similar ancestral backgrounds, believing that such an approach would make it easier to identify changes in their genetic sequence that cause disease. Now, geneticists are scrambling to diversify these gene pools after realizing that a more diverse gene pool actually helps them better understand disease biology.
“A large number of genes have been described as increasing the risk of IBD, but they have all been described in Europeans. But what if the same genes are also found across the different breeds? Well, that means these genes must be very important,” he said. Dr. Abreu: “We’d like to explode the way we study these diseases.”
Cuban immigrants have begun to appear early in recent years
Dr. Abreu doesn’t want to predict any outcomes, but her colleague Oriana Damas, MD, found that people of Hispanic descent may develop IBD after arriving in the United States due to the drastic change in their diets, and the ever-increasing number of food additives used in the United States. , and other environmental factors that lead to broad changes in the intestinal microflora.
A study conducted by Dr. Damas at the Crohn’s and Colitis Center found that Cuban immigrants developed IBD an average of seven years after immigrating, compared to an average of 30 years for the disease several decades ago. The NIH study will allow her to extend these findings to immigrants from Mexico, Central America, South America, and the Caribbean.
“We think the real change that’s happening is diet and gut bacteria,” she said.
Dr.. Abreu and McCauley are working with six other universities selected to participate in the NIH grant as genetic research centers within the Inflammatory Bowel Disease Genetics Consortium (IBDGC) to conduct the study. They expect to begin recruiting volunteers to donate blood and saliva samples in early 2023, hoping to attract enough Hispanics with IBD-; and without it -; To obtain a complete set of genetic sequences for study.
For Dr. McCauley, the NIH study represents another step in his ongoing efforts to diversify the pool of genes available to scientists. In addition to the work that he and Dr. Abreu have done both locally and within the IBDGC, Dr. McCauley is also a founding member of the Hispanic Multiple Sclerosis Research Alliance, which seeks to expand knowledge of another complex disease, multiple sclerosis, in Hispanic communities. It’s also involved in the National Institutes of Health’s All Among Us Research Program, which is trying to collect one million genetic sequences across the country that researchers can use in large-scale research projects.
McCauley said the diversity of genes available for study is particularly important in Miami, because the community is made up of many immigrants and people from Latin America.
“This is the community we serve in South Florida,” he said. “We are one of the most diverse communities in the country. I think this is a huge value for the research we do.”