The study showed that one of the risk variants reduces the expression of a gene -- ITPKC – on chromosome l9. Lower levels of ITPKC lead to over-activation of T cells -- white blood cells known as lymphocytes that play a central role in immunity.

Lead author, Dr. Yoshi Onouchi, SNP Research Center, RIKEN, in Yokohama, Japan, said the findings may help researchers understand how genetic regulators of the immune system respond to inflammation.

Scientists found this genetic variation also influences the response to treatment such as intravenous immunoglobulin, and the risk of developing a coronary artery aneurysm, a swelling of the artery that can result in blood clots and heart attack. These are all complications of KD -- a pediatric illness characterized by fever and rash.

Onouchi used DNA from hundreds of U.S. children and their parents collected through the Kawasaki Disease Research Center, at the University of California, San Diego School of Medicine.

"This was a wonderful collaboration," co-author, Dr. Jane Burns of UCSD said in a statement. "Dr. Onouchi used our DNA to make this observation. Now we are building on that observation."