A variant in a gene called ITPKC is associated with increased susceptibility to Kawasaki disease, reports a paper to be published online in Nature Genetics. Kawasaki disease is characterized by acute inflammation of the vascular system in infants and children, and if left untreated can lead to lethal coronary artery aneurysms.
Kawasaki disease tends to run in families, suggesting that there are genetic components to disease risk. It is also 10-20 times more common in Japan than in Western countries. Yoshihiro Onouchi and colleagues identified a region on chromosome 19 that was linked with the disease, and in particular a series of variants across four genes in the region were found more frequently in individuals with the disease than in healthy controls. The authors focused on one of these genes, ITPKC, which they regarded as the best candidate. ITPKC encodes an enzyme that is part of a signaling pathway with a critical role in certain cells of the immune system (T-cells). The authors went on to show that one of the risk variants reduces the expression of ITPKC, and that lower levels of ITPKC promote activation of T-cells. This is consistent with the marked activation of the immune system seen in Kawasaki disease. ITPKC with Kawasaki disease may have immediate clinical implications. Approximately 10-20% of affected individuals are resistant to the standard treatment of intravenous immunoglobulins, but individuals with the ITPKC risk variant are 4-5 times more likely to fail to improve on the standard therapy. If these individuals could be identified with a genetic test, they could be offered alternative and more intensive therapies.
Yoshihiro Onouchi (SNP Research Center, RIKEN, Yokohama, Japan)
Abstract available online.
(C) Nature Genetics press release.
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