Researchers, using a method called genome-wide association study, have illuminated the genetic underpinnings of high serum urate, the blood condition that brings on gout. The study, co-led by scientists at the Johns Hopkins Bloomberg School of Public Health, will inform efforts to develop screening tests for gout risk as well as potential new treatments.
The paper was published October 2 in Nature Genetics.
For their analysis, the researchers combined DNA and serum urate data from 457,690 individuals participating in 74 studies, and revealed 183 sites, or “loci,” in the genome where DNA variations are strongly associated with high urate levels. The vast majority of these loci had not been identified in prior studies. The researchers mapped many of the loci to specific genes and found that a large proportion are active in liver and kidney cells, sites of urate generation and excretion, respectively. They also showed that the 183 urate-associated loci could be used to predict gout risk in an independent group of more than 300,000 people.
Gout occurs when urate (also called uric acid) becomes too concentrated in the blood and precipitates into solid crystals, most frequently in the joints. Urate is a breakdown product of purine molecules, which are found much more in meat- or shellfish-heavy diets than in vegetarian diets. Alcoholic beverages, particularly beer, are also high in purine content. Gout has been increasing in prevalence around the world as many countries’ diets have grown richer.
Of the 183 loci on the human genome where DNA variations are strongly linked to high serum urate levels, only 36 had been revealed in prior studies.Friday Letter Submission, Publish on October 11