RIKEN’s Yukinori Okada on rheumatoid arthritis: ‘Genetic research has the potential to advance our understanding of the disease’

A research institution in Japan has found new genetic risk factors for rheumatoid arthritis that could help in new treatments for the autoimmune disease.

Researchers for RIKEN conducted a “large genetic study” of “five different ancestral backgrounds” that “identified 124 genetic markers, 34 of which are novel, that can influence the risk of developing rheumatoid arthritis,” a news release said. RIKEN was founded in 1917 in Tokyo as a private research foundation, according to its website.

“While there have been some recent advances in the treatment of rheumatoid arthritis, these medications don’t work for everyone—and a cure has yet to be identified,” Yukinori Okada of the RIKEN Center for Integrative Medical Sciences said in the release. “Genetic research has the potential to advance our understanding of the disease, revealing new clues that could inspire effective novel treatment strategies.”

The immune system of a person who has rheumatoid arthritis mistakenly attacks the person’s joint tissues, which causes inflammation and pain, the release said. Genetic and environmental factors interact to cause the complex disease.

“Many genes are involved in determining a person’s susceptibility to rheumatoid arthritis, with each contributing a small amount to the overall risk of developing the disease,” the release said. “A better understanding of the genetics of the condition could help advance new treatments for it.”

Scientists identify genetic markers associated with rheumatoid arthritis by comparing genomes from healthy people with people who have the condition in genome-wide association studies, according to the release. The largest studies previously focused “on people of European or East Asian ancestral background.”

“Now, Okada and his colleagues have conducted a large multi-ancestry GWAS that analyzed the genomic data of more than 275,000 people, 65% of whom had non-European ancestry,” the release said. “In participants with European, East Asian, African, South Asian and Arab ancestries, the analysis identified 34 genetic markers associated with rheumatoid arthritis that had never been found before. Candidate genes at these new locations are involved in the immune system and joint tissues, revealing novel insights into the causes of the disease.”

Okada said in the release that the “study is one of the largest and most ancestrally diverse GWAS of rheumatoid arthritis to date, revealing several new insights into the biology of the disease.”

“The study highlights the importance of further efforts to diversify studies and increase sample sizes from underrepresented ancestries to improve the power of these analyses—and the accuracy of polygenic risk scores, especially in non-European ancestral groups,” Okada concluded.