Identification of KCNN2 as a susceptibility locus for coronary artery aneurysms in Kawasaki disease using genome-wide association analysis.

Kawasaki disease (KD) is often complicated by coronary artery lesions (CALs), including aneurysms. Because of the complications associated with KD, this disorder is the leading cause of acquired heart disease in children from developed countries. To identify genetic loci that confer a higher risk of developing CALs, we performed a case-control association study using previous genome-wide association study data for samples from KD cases only (n=186) by grouping KD patients without CALs (control: n=123) vs KD patients with extremely large aneurysms (diameter>5 mm) (case: n=17). Twelve loci with one or more sequence variants were found to be significantly associated with CALs (P<1 × 10(-5)). Of these, an SNP (rs17136627) in the potassium intermediate/small conductance calcium-activated channel, subfamily N, member 2 (KCNN2) at 5q22.3 was validated in 32 KD patients with large aneurysms (diameter>5 mm) and 191 KD patients without CALs (odds ratio (OR)=12.6, P(combined)=1.96 × 10(-8)). This result indicates that the KCNN2 gene can have an important role in the development of coronary artery aneurysms in KD.

Assessment of risk factors for Korean children with Kawasaki disease.

Kawasaki disease (KD) is the most common cause of acquired heart disease in children. Intravenous immunoglobulin (IVIG) is the standard therapy for KD, but more than 10% of KD patients do not respond to IVIG and are at high risk for the development of coronary artery lesions (CALs). To identify clinical and genetic risk factors associated with CAL development and IVIG nonresponsiveness, this study analyzed the clinical data for 478 Korean KD patients. Multivariate logistic regression analysis showed that incomplete KD, IVIG nonresponse, fever duration of 7 days or longer, and the CC/AC genotypes of the rs7604693 single nucleotide polymorphism (SNP) in the PELI1 gene were significantly associated with the development of CALs, with odds ratios (ORs) ranging from 2.06 to 3.04. The risk of CAL formation was synergistically increased by the addition of individual risk factors, particularly the genetic variant in the PELI1 gene. Multivariate analysis also showed that a serum albumin level of 3.6 g/dl or lower was significantly associated with nonresponsiveness to IVIG [OR, 2.76; 95% confidence interval (CI), 1.34-5.68; P = 0.006]. Conclusively, incomplete KD, IVIG nonresponsiveness, long febrile days, and the rs7604693 genetic variant in the PELI1 gene are major risk factors for the development of CALs, whereas low serum albumin concentration is an independent risk factor for IVIG nonresponsiveness.

Distinct clinical courses according to presenting phenotypes and their correlations to ATP7B mutations in a large Wilson's disease cohort.

INTRODUCTION AND AIMS: Wide phenotypic and genotypic heterogeneities in Wilson's disease (WD) have been reported, hampering the study of their correlations. The goal of this study was to identify the factors related to these diversities. METHODS: Clinical courses and molecular genetic characteristics were analysed in 237 unrelated Korean WD families. The average follow-up period was 8.2 ± 5.8 years. RESULTS: Presenting phenotypes were classified as H1 (12.2%), H2 (42.4%), N1 (21.6%), N2 (0.4%), NX (0.4%), presymptomatic (22.4%) and other (0.4%), modifying the guidelines by Ferenci and colleagues. Age at presentation was youngest and cirrhosis was rarest in the presymptomatic group. Decompensated cirrhosis was the highest in the H1 group. Favourable outcome was rarest in the N1 group. Forty-seven (11 novel) ATP7B mutations were identified in 85% of the 474 alleles. Multiplex ligation-dependent probe amplification assays in ATP7B and analyses of ATOX1 and COMMD1 genes identified no additional mutations. Yeast complementation assays demonstrated functional perturbation of the seven novel missense mutants. Five major mutations, p.Arg778Leu, p.Ala874Val, p.Asn1270Ser, p.Lys838SerfsX35 and p.Leu1083Phe, accounted for 63% of the alleles. H1 was more common, age at presentation was younger and N1+N2+NX tended to be less common in patients with nonsense, frame shifting or splicing mutations than in those with missense mutations alone. Patients with both mutations in the transduction (Td) or the ATP hinge domain showed presymptomatic or hepatic manifestations but no neurological manifestation. CONCLUSIONS: The presenting phenotype strongly affects the clinical outcome of WD, and is related to the ATP7B mutation type and location, providing an evidence for genotype-phenotype correlations in WD.

A genome-wide association analysis reveals 1p31 and 2p13.3 as susceptibility loci for Kawasaki disease.

Kawasaki disease (KD) is an acute self-limited vasculitis of infants and children that manifests as fever and signs of mucocutaneous inflammation. Coronary artery aneurysms develop in approximately 15-25% of untreated children. Although the etiology of KD is largely unknown, epidemiologic data suggest the importance of genetic factors in the susceptibility to KD. In order to identify genetic variants that influence KD susceptibility, we performed a genome-wide association study (GWAS) using Affymetrix SNP array 6.0 in 186 Korean KD patients and 600 healthy controls; 18 and 26 genomic regions with one or more sequence variants were associated with KD and KD with coronary artery lesions (CALs), respectively (p < 1 × 10(-5)). Of these, one locus on chromosome 1p31 (rs527409) was replicated in 266 children with KD and 600 normal controls (odds ratio [OR] = 2.90, 95% confidence interval [CI] = 1.85-4.54, P (combined) = 1.46 × 10(-6)); and a PELI1 locus on chromosome 2p13.3 (rs7604693) was replicated in 86 KD patients with CALs and 600 controls (OR = 2.70, 95% CI = 1.77-4.12, P (combined) = 2.00 × 10(-6)). These results implicate a locus in the 1p31 region and the PELI1 gene locus in the 2p13.3 region as susceptibility loci for KD and CALs, respectively.

Genetic variants in the HLA-G region are associated with Kawasaki disease.

Kawasaki disease is an acute, self-limited vasculitis of infants and children, manifest as fever and signs of mucocutaneous inflammation. Treatment with high-dose immunoglobulin reduces systemic inflammation and prevents coronary artery lesions in Kawasaki disease. In this study, we investigated the possible association of the major histocompatibililty complex (MHC) region for the susceptibility to Kawasaki disease using an MHC panel of 2360 single nucleotide polymorphism (SNP) markers. Analysis of data obtained from screening MHC-specific SNP chips with 48 case and 90 control subjects revealed five candidate loci with significance levels of uncorrected p < 0.01. However, only one candidate locus (HLA-G) was confirmed to have a significant association with Kawasaki disease (rs2523790, odds ratio [OR] = 3.00, 95% confidence interval [95% CI] = 1.14-7.91, uncorrected p = 0.0263) in the replication study using 44 new case subjects and the previous 90 controls. In the fine mapping of the HLA-G locus, in particular, a nonsynonymous SNP (C/A) of the HLA-G gene (rs12722477, Leu134Ile) was significantly associated with Kawasaki disease (OR = 3.23, 95% CI = 1.12-9.32). A subgroup analysis showed that this association was more apparent in patients with coronary artery aneurysms (OR = 4.02, 95% CI = 1.23-13.19). Therefore, our results indicate that HLA-G may play a crucial role for the susceptibility to Kawasaki disease.