Identification of a shared genetic risk locus for Kawasaki disease and immunoglobulin A vasculitis by a cross-phenotype meta-analysis.

OBJECTIVES: Combining of genomic data of different pathologies as a single phenotype has emerged as a useful strategy to identify genetic risk loci shared among immune-mediated diseases. Our study aimed to increase our knowledge of the genetic contribution to Kawasaki disease (KD) and IgA vasculitis (IgAV) by performing the first comprehensive large-scale analysis on the genetic overlap between them. METHODS: A total of 1190 vasculitis patients and 11 302 healthy controls were analysed. First, in the discovery phase, genome-wide data of 405 KD patients and 6252 controls and 215 IgAV patients and 1324 controls, all of European origin, were combined using an inverse variance meta-analysis. Second, the top associated polymorphisms were selected for replication in additional independent cohorts (570 cases and 3726 controls). Polymorphisms with P-values ≤5 × 10-8 in the global IgAV-KD meta-analysis were considered as shared genetic risk loci. RESULTS: A genetic variant, rs3743841, located in an intron of the NAGPA gene, reached genome-wide significance in the cross-disease meta-analysis (P = 8.06 × 10-10). Additionally, when IgAV was individually analysed, a strong association between rs3743841 and this vasculitis was also evident [P = 1.25 × 10-7; odds ratio = 1.47 (95% CI 1.27, 1.69)]. In silico functional annotation showed that this polymorphism acts as a regulatory variant modulating the expression levels of the NAGPA and SEC14L5 genes. CONCLUSION: We identified a new risk locus with pleiotropic effects on the two childhood vasculitides analysed. This locus represents the strongest non-HLA signal described for IgAV to date.

Association of an IGHV3-66 gene variant with Kawasaki disease.

In a meta-analysis of three GWAS for susceptibility to Kawasaki disease (KD) conducted in Japan, Korea, and Taiwan and follow-up studies with a total of 11,265 subjects (3428 cases and 7837 controls), a significantly associated SNV in the immunoglobulin heavy variable gene (IGHV) cluster in 14q33.32 was identified (rs4774175; OR = 1.20, P = 6.0 × 10-9). Investigation of nonsynonymous SNVs of the IGHV cluster in 9335 Japanese subjects identified the C allele of rs6423677, located in IGHV3-66, as the most significant reproducible association (OR = 1.25, P = 6.8 × 10-10 in 3603 cases and 5731 controls). We observed highly skewed allelic usage of IGHV3-66, wherein the rs6423677 A allele was nearly abolished in the transcripts in peripheral blood mononuclear cells of both KD patients and healthy adults. Association of the high-expression allele with KD strongly indicates some active roles of B-cells or endogenous immunoglobulins in the disease pathogenesis. Considering that significant association of SNVs in the IGHV region with disease susceptibility was previously known only for rheumatic heart disease (RHD), a complication of acute rheumatic fever (ARF), these observations suggest that common B-cell related mechanisms may mediate the symptomology of KD and ARF as well as RHD.

Hygiene Hypothesis as the Etiology of Kawasaki Disease: Dysregulation of Early B Cell Development.

Kawasaki disease (KD) is an acute systemic vasculitis that occurs predominantly in children under 5 years of age. Despite much study, the etiology of KD remains unknown. However, epidemiological and immunological data support the hygiene hypothesis as a possible etiology. It is thought that more sterile or clean modern living environments due to increased use of sanitizing agents, antibiotics, and formula feeding result in a lack of immunological challenges, leading to defective or dysregulated B cell development, accompanied by low IgG and high IgE levels. A lack of B cell immunity may increase sensitivity to unknown environmental triggers that are nonpathogenic in healthy individuals. Genetic studies of KD show that all of the KD susceptibility genes identified by genome-wide association studies are involved in B cell development and function, particularly in early B cell development (from the pro-B to pre-B cell stage). The fact that intravenous immunoglobulin is an effective therapy for KD supports this hypothesis. In this review, I discuss clinical, epidemiological, immunological, and genetic studies showing that the etiopathogenesis of KD in infants and toddlers can be explained by the hygiene hypothesis, and particularly by defects or dysregulation during early B cell development.

Identification of SAMD9L as a susceptibility locus for intravenous immunoglobulin resistance in Kawasaki disease by genome-wide association analysis.

Kawasaki disease (KD) is a systemic vasculitis affecting infants and children; it manifests as fever and signs of mucocutaneous inflammation. Intravenous immunoglobulin (IVIG) treatment effectively attenuates the fever and systemic inflammation. However, 10-20% patients are unresponsive to IVIG. To identify genetic variants influencing IVIG non-response in KD, a genome-wide association study (GWAS) and a replication study were performed using a total of 148 IVIG non-responders and 845 IVIG-responders in a Korean population. rs28662 in the sterile alpha motif domain-containing protein 9-like (SAMD9L) locus showed the most significant result in the joint analysis of GWAS and replication samples (odds ratio (OR) = 3.47, P = 1.39 × 10-5). The same SNP in the SAMD9L locus was tested in the Japanese population, and it revealed a more significant association in a meta-analysis with Japanese data (OR = 4.30, P = 5.30 × 10-6). These results provide new insights into the mechanism of IVIG response in KD.

Association of the IL16 Asn1147Lys polymorphism with intravenous immunoglobulin resistance in Kawasaki disease.

Kawasaki disease (KD) is an acute, self-limited vasculitis, mainly affecting children younger than 5 years old, with accompanying fever and signs of mucocutaneous inflammation. Intravenous immunoglobulin (IVIG) is the standard treatment for KD; however, ~15% of patients are resistant to IVIG treatment. To identify protein coding genetic variants influencing IVIG resistance, we re-analyzed our previous genome-wide association study (GWAS) data from 296 patients with KD, including 101 IVIG non-responders and 195 IVIG responders. Five nonsynonymous SNPs (nsSNPs) in five immune-related genes, including a previously reported SAMD9L nsSNP (rs10488532; p.Val266Ile), were associated with IVIG non-response (odds ratio [OR] = 1.89-3.46, P = 0.0109-0.0035). In a replication study of the four newly-identified nsSNPs, only one in the interleukin 16 (IL16) gene (rs11556218, p.Asn1147Lys) showed a trend of association with IVIG non-response (OR = 1.54, P = 0.0078). The same IL16 nsSNP was more significantly associated with IVIG non-response in combined analysis of all data (OR = 1.64, P = 1.25 × 10-4). Furthermore, risk allele combination of the IL16 CT and SAMD9L TT nsSNP genotypes exhibited a very strong effect size (OR = 9.19, P = 3.63 × 10-4). These results implicate IL16 as involved in the mechanism of IVIG resistance in KD.

Are Genetic Variants Associated with the Location of Cerebral Arterial Lesions in Stroke Patients?

BACKGROUND: Genetic variants may play a role in determining the location of cerebral atherosclerosis. We aimed to investigate the association between RNF213, MMP2, and genetic polymorphisms linked to vascular tortuosity with the location of cerebral arterial atherosclerosis. METHODS: A prospective case-control study was conducted on patients with ischemic stroke and age- and sex-matched stroke-free controls. The stroke patients were categorized into those with intracranial artery atherosclerosis (ICAS), extracranial artery atherosclerosis (ECAS), and small vessel occlusion (SVO). Six single nucleotide polymorphisms (SNPs) including rs2118181 (FBN1), rs2179357 (SLC2A10), rs1036095 (TGFBR2), rs243865 (MMP2), rs1800470 (TGFB1), and rs112735431 (RNF213) were analyzed with the TaqMan Genotyping Assay, and the distribution of genotypes across groups was compared. RESULTS: None of the 6 SNPs were associated with stroke on comparing the 449 stroke patients (71 with ECAS, 169 with ICAS, and 209 with SVO) to the 447 controls. In the subgroup analysis, the adjusted odds ratios (aORs) for age and sex indicated a significant association between rs112735431 and ICAS in the allele comparison analysis and in the additive and dominant model analyses. rs112735431 was associated with anterior circulation involvement and increased burden of cerebral atherosclerosis. rs2179357 was significantly associated with ICAS in the recessive model analysis, and rs1800470 was significantly associated with ECAS in the recessive model analysis when compared to controls. CONCLUSION: rs112735431 was associated with ICAS and increased atherosclerosis burden in Korean stroke patients. Further studies are needed to elucidate the role of rs112735431 and to confirm the association of rs2179357 and rs1800470 with cerebral atherosclerosis.

Identification of the TIFAB Gene as a Susceptibility Locus for Coronary Artery Aneurysm in Patients with Kawasaki Disease.

Kawasaki disease (KD) is a self-limiting systemic vasculitis of unknown etiology. KD is often complicated by coronary artery aneurysms (CAAs), which develop in about 20-25% of untreated children and 3-5% of children treated with intravenous immunoglobulin therapy. To identify the risk loci for CAA susceptibility in patients with KD, we performed a genome-wide association study (GWAS) using our previous Illumina HumanOmni1-Quad BeadChip data (296 KD patients) and a new replication study in an independent sample set (713 KD patients) by grouping KD patients without CAA (control) versus KD patients with extremely large aneurysms (diameter ≥ 5 mm) (case). Among 44 candidate single -nucleotide polymorphisms (SNPs) selected from the initial GWAS data (33 cases vs. 215 controls), a SNP (rs899162) located 7 kb upstream of the TIFAB gene on chromosome five was replicated in an independent sample (12 cases vs. 532 controls). In the combined analysis (45 cases vs. 747 controls), the SNP (rs899162) showed a highly significant association with CAA formation (diameter ≥ 5 mm) in patients with KD (odds ratio = 3.20, 95% confidence interval = 2.02-5.05, Pcombined = 1.95 × 10-7). These results indicate that the TIFAB gene may act as a CAA susceptibility locus in patients with KD.

A genome-wide association analysis identifies NMNAT2 and HCP5 as susceptibility loci for Kawasaki disease.

Kawasaki disease (KD), a systemic vasculitis of infants and children, manifests as fever and mucocutaneous inflammation. Although its etiology is largely unknown, the epidemiological data suggest that genetic factors are important in KD susceptibility. To identify genetic variants influencing KD susceptibility, we performed a genome-wide association study (GWAS) and replication study using a total of 915 children with KD and 4553 controls in the Korean population. Six single-nucleotide polymorphisms (SNPs) in three loci were associated significantly with KD susceptibility (P<1.0 × 10-5), including the previously reported BLK locus (rs6993775, odds ratio (OR)=1.52, P=2.52 × 10-11). The other two loci were newly identified: NMNAT2 on chromosome 1q25.3 (rs2078087, OR=1.33, P=1.15 × 10-6) and the human leukocyte antigen (HLA) region on chromosome 6p21.3 (HLA-C, HLA-B, MICA and HCP5) (rs9380242, rs9378199, rs9266669 and rs6938467; OR=1.33-1.51, P=8.93 × 10-6 to 5.24 × 10-8). Additionally, SNP rs17280682 in NLRP14 was associated significantly with KD with a family history (18 cases vs 4553 controls, OR=6.76, P=5.46 × 10-6). These results provide new insights into the pathogenesis and pathophysiology of KD.

Associations between the neuron-specific glucocorticoid receptor (NR3C1) Bcl-1 polymorphisms and suicide in cancer patients within the first year of diagnosis.

BACKGROUND: Cancer diagnosis is associated with an increased suicide risk, particularly within the first 1 year after diagnosis of cancer. Abnormal function of the hypothalamic-pituitary-adrenal axis has been implicated in the pathophysiology of depression and suicide. We examined genetic associations of the functional Bcl-1 polymorphism of (rs41423247) neuron-specific glucocorticoid receptor (NR3C1) gene, with death by suicide in cancer patients. Suicides occurring within a year of cancer diagnosis ('early suicide') were considered separately from those suicides during the second or subsequent year ('late suicide') after cancer diagnosis. METHODS: The subjects consisted of 343 cancer patients admitted to a general hospital in Seoul, South Korea from 1996 to 2009, of which 182 had died by suicide and 161 were alive on December 31, 2009. Genomic DNA was extracted from formalin-fixed paraffin-embedded tissue sample of patients with cancer. We conducted a case-control association analysis of Bcl-1 polymorphism of NR3C1 gene. RESULTS: Subjects carrying the GG genotype of Bcl-1 polymorphism were at increased risk of early suicide when compared to those carrying the CC genotype (OR 3.80, 95 % CI 1.02-14.16, p = .047). Similarly, those individuals carrying the GG genotype (recessive mode) had an increased risk of early suicide relative to the CC or CG genotype (OR 3.71, 95 % CI 1.03-13.43, p = .045). However, there were no differences in the genotype distributions of the NR3C1 Bcl-1 polymorphism between late suicide cases and controls. CONCLUSIONS: Our findings suggest that the NR3C1 Bcl-1 polymorphisms may be involved in the susceptibility to suicide within the first year after cancer diagnosis among cancer patients in Korean population.

JAK2 V617F, MPL, and CALR Mutations in Korean Patients with Essential Thrombocythemia and Primary Myelofibrosis.

Mutations in the calreticulin gene, CALR, have recently been discovered in subsets of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). We investigated Korean patients with ET and PMF to determine the prevalence, and clinical and laboratory correlations of CALR/JAK2/MPL mutations. Among 84 ET patients, CALR mutations were detected in 23 (27.4%) and were associated with higher platelet counts (P=0.006) and lower leukocyte counts (P=0.035) than the JAK2 V617F mutation. Among 50 PMF patients, CALR mutations were detected in 11 (22.0%) and were also associated with higher platelet counts (P=0.035) and trended to a lower rate of cytogenetic abnormalities (P=0.059) than the JAK2 V617F mutation. By multivariate analysis, triple-negative status was associated with shorter overall survival (HR, 7.0; 95% CI, 1.6-31.1, P=0.01) and leukemia-free survival (HR, 6.3; 95% CI, 1.8-22.0, P=0.004) in patients with PMF. The type 1 mutation was the most common (61.1%) type among all patients with CALR mutations, and tended toward statistical predominance in PMF patients. All 3 mutations were mutually exclusive and were never detected in patients with other myeloid neoplasms showing thrombocytosis. CALR mutations characterize a distinct group of Korean ET and PMF patients. Triple-negative PMF patients in particular have an unfavorable prognosis, which supports the idea that triple-negative PMF is a molecularly high-risk disease.

Common variants in the CRP promoter are associated with a high C-reactive protein level in Kawasaki disease.

Kawasaki disease (KD) is an acute self-limiting form of vasculitis that afflicts infants and children and manifests as fever and signs of mucocutaneous inflammation. Children with KD show various laboratory inflammatory abnormalities, such as elevations in their white blood cell (WBC) count, C-reactive protein (CRP) level, and erythrocyte sedimentation rate (ESR). We here performed a genome-wide association study (GWAS) of 178 KD patients to identify the genetic loci that influence 10 important KD laboratory markers: WBC count, neutrophil count, platelet count, CRP, ESR, hemoglobin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, and total protein. A total of 165 loci passed our arbitrary stage 1 threshold for replication (p < 1 × 10(-5)). Of these, only 2 SNPs (rs12068753 and rs4786091) demonstrated a significant association with the CRP level in replication study of 473 KD patients (p < 0.05). The SNP located at the CRP locus (rs12068753) demonstrated the most significant association with CRP in KD patients (beta = 4.73 and p = 1.20 × 10(-6) according to the stage 1 GWAS; beta = 3.65 and p = 1.35 × 10(-8) according to the replication study; beta = 3.97 and p = 1.11 × 10(-13) according to combined analysis) and explained 8.1% of the phenotypic variation observed. However, this SNP did not demonstrate any significant association with CRP in the general population (beta = 0.37 and p = 0.1732) and only explained 0.1% of the phenotypic variation in this instance. Furthermore, rs12068753 did not affect the development of coronary artery lesions or intravenous immunoglobulin resistance in KD patients. These results indicate that common variants in the CRP promoter can play an important role in the CRP levels in KD.

Sex-Specific Susceptibility Loci Associated With Coronary Artery Aneurysms in Patients With Kawasaki Disease.

BACKGROUND AND OBJECTIVES: Kawasaki disease (KD) is an acute vasculitis that primarily affects children under age 5 years. Approximately 20-25% of untreated children with KD and 3-5% of those treated with intravenous immunoglobulin therapy develop coronary artery aneurysms (CAAs). The prevalence of CAAs is much higher in male than in female patients with KD, but the underlying factors contributing to susceptibility to CAAs in patients with KD remain unclear. This study aimed to identify sex-specific susceptibility loci associated with CAAs in KD patients. METHODS: A sex-stratified genome-wide association study (GWAS) was performed using previously obtained GWAS data from 296 KD patients and a new replication study in an independent set of 976 KD patients by comparing KD patients without CAA (controls) and KD patients with aneurysms (internal diameter ≥5 mm) (cases). RESULTS: Six male-specific susceptibility loci, PDE1C, NOS3, DLG2, CPNE8, FUNDC1, and GABRQ (odds ratios [ORs], 2.25-9.98; p=0.00204-1.96×10-6), and 2 female-specific susceptibility loci, SMAD3 (OR, 4.59; p=0.00016) and IL1RAPL1 (OR, 4.35; p=0.00026), were significantly associated with CAAs in patients with KD. In addition, the numbers of CAA risk alleles additively contributed to the development of CAAs in patients with KD. CONCLUSIONS: A sex-stratified GWAS identified 6 male-specific (PDE1C, NOS3, DLG2, CPNE8, FUNDC1, and GABRQ) and 2 female-specific (SMAD3 and IL1RAPL1) CAA susceptibility loci in patients with KD.

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.

Identification of B-cell-related HSPG2 and CDSN as susceptibility loci for Kawasaki disease.

Kawasaki disease (KD) is an acute pediatric vasculitis that predominantly affects children under the age of 5 years. To date, genome-wide association studies (GWAS) have identified several KD susceptibility genes (e.g., BLK, CD40, FCGR2A, BCL2L11, and IGHV), which are mainly involved in B cell immunity. In this study, we aimed to identify additional KD susceptibility genes mainly involved in B cell development and functions by analyzing our previous GWAS data and conducting a replication study using new sample. Initially, we selected 30 single nucleotide polymorphisms (SNPs) in B-cell-related genes that were significantly (P < 0.01) associated with KD in our previous GWAS analysis of 247 KD cases with complete type and 1,000 healthy controls. Replication study was performed by genotyping the new 837 KD case samples with Fluidigm system and comparing them with 3,553 control genotypes. Among the 30 candidate SNPs, two were significantly associated with KD (P < 0.001) in the replication study. An even greater association between these SNPs and KD was observed in the combined analysis of GWAS and replication samples: odds ratio (OR) = 1.97 (P = 8.61 × 10-6) for rs2270699 (nonsynonymous SNP: c.10588C > T, p.Arg3530Trp) in the heparan sulfate proteoglycan 2 (HSPG2) gene and OR = 1.28 (P = 1.34 × 10-6) for rs3130992 (intronic SNP) in both the corneodesmosin (CDSN) and psoriasis susceptibility 1 candidate 1 (PSORS1C1) genes. These results suggest that the B-cell-related genes, HSPG2 and CDSN or PSORS1C1, play a role in the development of KD.

Exome sequencing and subsequent association studies identify five amino acid-altering variants influencing human height.

Height is a highly heritable trait that involves multiple genetic loci. To identify causal variants that influence stature, we sequenced whole exomes of four children with idiopathic short stature. Ninety-five nonsynonymous single-nucleotide polymorphisms (nsSNPs) were selected as potential candidate variants. We performed association analysis in 740 cohort individuals and identified 11 nsSNPs in 10 loci (DIS3L2, ZBTB38, FAM154A, PTCH1, TSSC4, KIF18A, GPR133, ACAN, FAM59A, and NINL) associated with adult height (P < 0.05), including five novel loci. Of these, two nsSNPs (TSSC4 and KIF18A loci) were significant at P < 0.05 in the replication study (n = 1,000) and five (ZBTB38, FAM154A, TSSC4, KIF18A, and FAM59A loci) were significant at P < 0.01 in the combined analysis (n = 1,740). Together, the five nsSNPs accounted for approximately 2.5% of the height variation. This study demonstrated the utility of next-generation sequencing in identifying genetic variants and loci associated with complex traits.

Comparison between aniridia with and without PAX6 mutations: clinical and molecular analysis in 14 Korean patients with aniridia.

PURPOSE: To describe clinical and molecular characteristics of Korean patients with aniridia and to compare the clinical phenotype between those having an identifiable PAX6 mutation and those not. DESIGN: Comparative case series. PARTICIPANTS: A total of 14 Korean patients from 10 families with aniridia. METHODS: Complete ophthalmologic examinations were performed for all patients. PAX6 analysis included direct sequencing of all coding regions and multiplex ligation-dependent probe amplification (MLPA) to detect large deletions when the sequencing was negative. If the PAX6 analysis failed to reveal any identifiable mutations, genomic copy number variation analysis via array comparative genomic hybridization (CGH) and candidate gene PITX3 and FOXE3 sequencing were then performed. MAIN OUTCOME MEASURES: Severity of ocular abnormalities and genetic findings. RESULTS: Sequencing of PAX6 exhibited 5 different heterozygous mutations in 8 patients from 5 families; 2 (p.Ser43Phe, IVS8-9C>G) were novel, and 3 (p.Arg208Trp, p.Arg317X, and p.X423L) have been previously reported. Among the remaining 6 patients in whom the PAX6 sequencing was negative, MLPA identified large deletions in 2 sporadic patients. However, the array CGH and candidate gene sequencing found no genomic or genetic abnormalities. The mutation detection rate was therefore 70%. Patients harboring an identifiable mutation in PAX6 had either a severe or a mild variant phenotype depending on the type of mutations. Likewise, among patients without an identifiable PAX6 mutation, their phenotypes varied widely from severe to very mild. CONCLUSIONS: This study adds 2 novel PAX6 mutations to those previously reported, providing further evidence for genetic and phenotypic heterogeneity in aniridic ocular malformation. There was no difference in the clinical phenotype between patients with and without detectable mutations in the PAX6 gene. The wide variability of ocular phenotype regardless of the presence or absence of PAX6 mutations calls for a further appreciation of the complexity in the molecular diagnosis of aniridia and suggests that this ocular malformation may be better regarded as a group of heterogeneous disorders, rather than a single disease entity, associated with mutations in PAX6 and/or other genes located elsewhere in the human genome. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article.

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.

Variations in the number of CCL3L1 gene copies and Kawasaki disease in Korean children.

High-dose intravenous immunoglobulin (IVIG) therapy is the highly effective and standard treatment for Kawasaki disease (KD). However, ~20 % of KD patients have persistent fever or recurrence of fever after the initial IVIG treatment, which increases the risk for coronary artery lesions (CALs). Furthermore, the mechanism of IVIG resistance in KD patients still is unknown. The number of CC chemokine ligand 3-like 1 (CCL3L1) gene copies is reported to be associated with KD and IVIG resistance in Japanese patients. In addition, the authors observed significant upregulation of the CCL3L1 gene expression after in vitro immunoglobulin treatment in B cell lines derived from KD patients. Therefore, this study of 459 KD patients and 496 healthy control subjects tested whether the number of CCL3L1 gene copies is associated with a risk of KD, CALs, and/or IVIG resistance in Korean KD patients. However, the number of CCL3L1 gene copies was not associated with KD (P = 0.18), CAL formation (P = 0.062), or the IVIG resistance (P = 0.90). Therefore, the results indicate that the number of CCL3L1 gene copies does not have a role in susceptibility to KD or CALs nor with IVIG resistance in Korean KD patients.

Whole Exome Sequencing in Patients with Phenotypically Associated Familial Intracranial Aneurysm.

OBJECTIVE: Familial intracranial aneurysms (FIAs) are found in approximately 6%-20% of patients with intracranial aneurysms (IAs), suggesting that genetic predisposition likely plays a role in its pathogenesis. The aim of this study was to identify possible IA-associated variants using whole exome sequencing (WES) in selected Korean families with FIA. MATERIALS AND METHODS: Among the 26 families in our institutional database with two or more IA-affected first-degree relatives, three families that were genetically enriched (multiple, early onset, or common site involvement within the families) for IA were selected for WES. Filtering strategies, including a family-based approach and knowledge-based prioritization, were applied to derive possible IA-associated variants from the families. A chromosomal microarray was performed to detect relatively large chromosomal abnormalities. RESULTS: Thirteen individuals from the three families were sequenced, of whom seven had IAs. We noted three rare, potentially deleterious variants (PLOD3 c.1315G>A, NTM c.968C>T, and CHST14 c.58C>T), which are the most promising candidates among the 11 potential IA-associated variants considering gene-phenotype relationships, gene function, co-segregation, and variant pathogenicity. Microarray analysis did not reveal any significant copy number variants in the families. CONCLUSION: Using WES, we found that rare, potentially deleterious variants in PLOD3, NTM, and CHST14 genes are likely responsible for the subsets of FIAs in a cohort of Korean families.

The association of a single-nucleotide polymorphism of the IL-2 inducible T-cell Kinase gene with asthma.

Asthma manifests as TH2-dominant airway inflammation regulated by inducible T-cell kinase (ITK). To investigate associations between genetic variants of the ITK gene and asthma, 31 single-nucleotide polymorphisms (SNPs) were genotyped in 303 normal controls and 498 asthmatics and the two groups were compared using logistic regression models. The functional effects of the ITK promoter SNP were assessed using pGL3 luciferase reporter systems and gel-shift assays. The minor allele-196C>T in the promoter region of the ITK gene was significantly more frequent in asthmatics than in controls. The luciferase activity of the PGL3-ITK-196T allele construct was higher than that of the -196C allele. In the gel-shift assay, -196T double-stranded oligonucleotides bound more strongly to Jurkat cell nuclear protein compared to the -196C double-stranded oligonucleotides. People with the -rare allele 196C>T may be more susceptible to asthma via transcriptional regulation of the ITK gene.