The incidence and prevalence of gout across indigenous groups from places like Europe, Asia, and Africa are different from what is seen in people from the United States, according to research. Studies suggest that genetics can significantly modulate risks for gout and for hyperuricemia—which usually precedes gout—after exposure to specific environmental or dietary factors. “Worldwide, there are significant health disparities in the prevalence of gout,” explains Youssef Roman, PharmD, PhD. “In addition, some people will develop gout rapidly and others can have more severe form of the disease. By gaining a better understanding of genetic and epigenetic risk factors for gout across ethnic groups, clinicians may be able to improve how specific populations are managed and can potentially reduce disparities in gout care.”

 

Comparing Patterns in Different Racial Groups

Dr. Roman and his group had a study published in the Journal of Personalized Medicine that estimated the frequency of risk alleles associated with elevated serum urate levels or gout in select racial groups when compared with Europeans. “Some of these risk alleles are of great interest because they may play a role in personalizing diet and treatment plans in gout,” Dr. Roman says. “We wanted to interrogate specific genes as contributing factors to racial health disparities in gout prevalence and clarify possible genetic sources of differential responses to urate-lowering therapies for patients in the US.”

For the study, investigators first conducted a literature review to determine the global prevalence of gout. They then compared the frequency of urate-related genetic risk alleles between Europeans and four major racial groups from the 1,000 Genomes Project: 1) Africans in the Southwest US, 2) Han-Chinese, 3) Japanese, and 4) Mexicans. “Using the 1,000 Genomes Project database, we compared the frequency of alleles of 11 single nucleotide polymorphisms across 11 genes that are physiologically involved and significantly associated with serum urate levels and gout risk,” says Dr. Roman (Figure). “Our goal was to identify similarities and differences in patterns of disease prevalence relative to risk allele frequencies.”

 

Gout: A Western World Phenomenon

According to the study, the prevalence of hyperuricemia and gout was higher in Western countries when compared with non-U.S. populations. “Gout appeared to be a western world phenomenon,” Dr. Roman says. “Asians had higher risks for hyperuricemia and gout than other populations assessed in our study.” When compared with Europeans, Han-Chinese and Japanese populations had the highest hyperuricemia or gout risk allele frequencies, followed by Mexicans and Africans in the Southwest US. Specifically, nine alleles in Han-Chinese populations and 11 alleles in Japanese populations were considered hyperuricemia or gout risk alleles.

Dr. Roman says the study results are consistent with previous reports that Asian subgroups have a higher prevalence of hyperuricemia and gout when compared with non-Asians. “Our findings suggest a strong genetic component to the development of hyperuricemia and gout in Asian populations when compared with the European population,” he says. “It’s likely that genetics interact with environment in Asian subgroups with gout risk.” The differences in allele frequencies could be responsible for the differential prevalence of hyperuricemia and gout across distinct racial groups.

 

Making the Case for Personalizing Approaches

The data provide evidence to support the use of polygenic risk assessments for gout to personalize approaches with robust assessments rather than relying on racial stratification for disease risk or treatment selection, according to Dr. Roman. “Evaluating each person’s genetic information may guide efforts to tailor diet and medication for patients,” he says. “Genomics can help clinicians design personalized risk-mitigation strategies for patient groups at high risk for developing hyperuricemia or gout. With the strong association between hyperuricemia and cardiovascular diseases, use of genomics could help prevent suboptimal medication selection and reduce risks for new disease onset.”

Genomics has potential to improve healthcare outcomes and could help address existing health disparities associated with hyperuricemia and gout across different racial populations, which in turn can improve health equity. “Over the years, the field of genomics has advanced considerably as genetic platforms have improved and as costs have decreased,” Dr. Roman says. “As efforts increase to personalize medicine, the hope is to empower clinicians with decision support tools and the knowledge to use genomics to help select the most appropriate treatment for patients.”

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