Get Healthy!

• Posted October 31, 2025

Gene Test Can Predict Risk For Gout Medicine Side Effects

A new gene test might be able to predict which gout patients will have a bad skin reaction to a common medication for the condition, researchers say.

A newly discovered gene combined with an already known genetic factor could explain the risk of skin side effects in more than 80% of U.S. gout patients prescribed allopurinol, researchers reported Oct. 29 in JAMA Dermatology.

“We found a new genetic association, HLA-A*34:02, which appears very important as a risk factor in U.S. allopurinol severe cutaneous adverse reactions patients,” lead researcher Dr. Elizabeth Phillips said in a news release. She’s a professor of clinical research, medicine, dermatology, pharmacology and pathology, microbiology and immunology at Vanderbilt University Medical Center in Nashville, Tennessee.

Gout occurs when the kidneys are not able to filter out excess levels of uric acid from a person’s bloodstream. The uric acid forms needle-like crystals that lodge in joints, causing sudden and severe pain and swelling among gout patients.

Allopurinol reduces the production of uric acid in the body, but it also is associated with severe skin reactions in some patients.

One side effect, called Stevens-Johnson syndrome/toxic epidermal necrolysis, causes skin to rash, blister and peel. Most who develop this syndrome from allopurinol use are hospitalized, and as many as 30% die, researchers said in background notes.

A gene called HLA-B*58:01 already has been associated with skin side effects of allopurinol, researchers said. It accounts for nearly all cases of skin reactions in Southeast Asian patients, and it has long been used to screen there.

However, that gene misses more than one-third of patients at risk in the U.S., including up to 45% of Black patients, researchers said.

For the new study, researchers examined 16 patients with skin side effects caused by allopurinol. They found that HLA-B*58:01 was strongly associated with the side effects, but remained absent in a significant number of cases.

However, the patients also carried another gene, HLA-A*34:02, that filled in many of the gaps left by analysis using the first gene, the study found.

“The combination of HLA-A*34:02 and HLA-B*58:01 would help explain risk in over 80% of patients,” Phillips said.

The American College of Rheumatology currently recommends that screening for HLA-B*58:01 take place before prescribing allopurinol to Asian and Black patients in the U.S., researchers noted. Black patients are five times more likely than white patients to carry the gene.

Adding the new gene to screening recommendations might open up such testing to a wider population, researchers said.

However, gaps still remain, and caution is warranted when counseling any gout patient about allopurinol’s skin-related side effects, researchers said.

“Ultimately we would like to develop drug hypersensitivity panels that could more comprehensively identify patients at risk for severe reactions to drugs regardless of their population of origin,” Phillips said.

More information

The Arthritis Foundation has more on gout.

SOURCE: Vanderbilt University Medical Center, news release, Oct. 27, 2025