Genetic polymorphism of SMAD5 is associated with Kawasaki disease.

Mothers against decapentaplegic homolog (SMAD) proteins are intracellular mediators of members of the transforming growth factor-β (TGF-β) superfamily, which are activated by bone morphogenetic proteins (BMPs). On activation, SMAD5 forms heterometric SMAD complexes, which are translated to the nucleus where they regulate gene transcription. TGF-β induces T cell activation and cardiovascular disease, two important features of Kawasaki disease (KD), whereas BMP is associated with coronary artery disease. In this study, we hypothesized that single nucleotide polymorphisms (SNPs) of SMAD5 may be associated with KD and coronary arterial lesions (CALs). Genotyping for 15 SNPs of the SMAD5 gene (rs3764941, rs10085013, rs6596284, rs7356756, rs13179769, rs13166063, rs1109158, rs4585442, rs4146185, rs12719481, rs6865297, rs3206634, rs6871224, rs1057898, and rs7031) was performed by direct sequencing of 105 KD patients and 303 healthy adult controls. We also compared the allele frequencies between a CAL group (n = 31) and a normal coronary group (n = 74). Results showed that among the 15 SNPs, rs3206634 was significantly associated with KD in a recessive model (odds ratio = 2.31, p = 0.019), whereas there was no association between any of the 15 SNPs and CALs. These findings may be used as a risk factors development of KD or for future generations of therapeutic treatments for KD.