Johns Hopkins scientists out a gene for gout – ABCG2 gene mutation is responsible for causing the joint inflammation and pain that are symptoms of gout.
Having partnered last year with an international team that surveyed the genomes of 12,000 individuals to find a genetic cause for gout, Johns Hopkins scientists now have shown that the malfunctioning gene they helped uncover can lead to high concentrations of blood urate that forms crystals in joint tissue, causing inflammation and pain – the hallmark of this disease.
The ABCG2 gene, they found, makes a protein that normally transports urate out of the kidney and into urine before the waste product does any harm.
In studies using frog egg cells genetically engineered with human DNA, the Hopkins researchers established the role of the ABCG2 gene as a cause of gout, lending credence to suspicions that metabolic deficiencies, in addition to too much rich food and alcohol, are mostly to blame for this painful type of arthritis that affects 3 million Americans.
The gene, they believe, may be responsible for some 10 percent of gout in Caucasians.
A report on the research, funded by the National Institutes of Health, was published June 8 in the online Early Edition PNAS.
By analyzing associations between blood uric acid levels and genotypes, the researchers identified the gene known as ABCG2 and specifically a certain mutation as a candidate for causing the joint inflammation and pain that are symptoms of gout.
“As the first major gene identified to cause gout, we believe that ABCG2 also represents an attractive new drug target,” says Michael Kottgen, M.D., a biological chemistry research associate in the Johns Hopkins University School of Medicine. “We anticipate that activation of ABCG2 with a drug may help to promote excretion of urate.”
Source: Johns Hopkins Medical Institutions, USA