Shiguo Liu

Genetic analysis of ABCG2 gene C421A polymorphism with gout disease in Chinese Han male population

Gout is the most frequent inXammatory joint disease in men above 40 years of age (Luk and Simkin 2005). Recently, a genome-wide association study identiWed substantial associations between single nucleotide polymorphism (SNPs), rs2231142, in the ATP-binding cassette, sub-family G (WHITE), member 2 (ABCG2) and uric acid concentration and gout in both white and black individuals and may be a causal candidate variant (Dehghan et al. 2008). To clarify the global relevance of the variant rs2231142 (c. C421A), the association needs to be conWrmed by independent studies in diVerent ethnic groups. The objective of this study is to assess the genetic association of SNP in ABCG2 gene with gout in a Chinese Han male population. A total of 200 gout patients and 235 gout-free control were recruited in this study from Qingdao University. The diagnosis of gout was based on the preliminary criteria which was published by the American College of Rheumatology in 1977 for the classiWcation of gout for use in either clinical settings or population-based epidemiologic studies (Wallace et al. 1977). The rs2231142 and nearby regions were ampliWed by polymerase chain reaction (PCR) (PCR primers were shown on supplementary Table 1) and PCR product was sequenced by ABI 3730XL (Applied Biosystems, Foster City, CA) to perform mutational analysis. The associations between biochemical data and gout are listed in Table 1. There were signiWcant diVerence in rs2231142 genotypic and allelic frequencies between gout cases and controls (shown in Table 2). Compared with controls, there was a higher A/A genotype and A allele frequency of rs2231142 in the gout cases (21.8 vs. 8.4% by genotype; 44.9 vs. 32.3% by allele). And the association to gout reached signiWcance ( 2 = 15.91, P < 0.001, crude OR = 3.02, 95% CI 1.36–4.90 and OR (adjusted by age) = 1.80, 95% CI 1.32–2.45 by dominant mode; 2 = 6.82, P = 0.009, OR = 1.67 95% CI 1.54–2.27 by recessive mode). Compared with C/C genotype carriers, there was higher uric acid level in A allele carriers in the gout cases. However, the diVerence did not reach signiWcance (P = 0.066). Rs2231142, the missense SNP in ABCG2 (Q141 K) was associated with uric acid concentration and gout in both white and black individuals and may be a causal candidate variant also for Chinese Han people. The eVects of the polymorphism on the functions of ABCG2 in vitro have been revealed using transfectants that the individuals with the C/C genotype are presumed to have the highest transporter activity (Imai et al. 2002; Kondo et al. 2004; Mizuarai et al. 2004; Woodward et al. 2009). C421A also aVects the B. Wang and Z. Miao contributed equally to the work.

Genome-wide association analysis identifies three new risk loci for gout arthritis in Han Chinese

Gout is one of the most common types of inflammatory arthritis, caused by the deposition of monosodium urate crystals in and around the joints. Previous genome-wide association studies (GWASs) have identified many genetic loci associated with raised serum urate concentrations. However, hyperuricemia alone is not sufficient for the development of gout arthritis. Here we conduct a multistage GWAS in Han Chinese using 4,275 male gout patients and 6,272 normal male controls (1,255 cases and 1,848 controls were genome-wide genotyped), with an additional 1,644 hyperuricemic controls. We discover three new risk loci, 17q23.2 (rs11653176, P=1.36 × 10−13, BCAS3), 9p24.2 (rs12236871, P=1.48 × 10−10, RFX3) and 11p15.5 (rs179785, P=1.28 × 10−8, KCNQ1), which contain inflammatory candidate genes. Our results suggest that these loci are most likely related to the progression from hyperuricemia to inflammatory gout, which will provide new insights into the pathogenesis of gout arthritis.

Teratocarcinoma-derived growth factor 1 (TDGF1) sequence variants in patients with congenital heart defect

The goal of our study was to identify potential pathogenic mutations in the TDGF1 gene in Chinese people with isolated CHD, particularly those with VSD, and to provide further insight into the etiology of CHD. A total of 500 CHD Chinese patients were investigated for mutations in the TDGF1 gene. Thirteen variants were found among the 500 isolated VSD patients and 250 controls, including one non-synonymous variant identified in patients but not in controls. This work firstly provides human genetic evidence of TDGF1 involved in the pathogenesis of VSD, expanding our knowledge of the causative mutations of congenital heart defects, in particular, the causative mutations of VSD.

Genetic variations in IL1A and IL1RN are associated with the risk of preeclampsia in Chinese Han population

Preeclampsia (PE) is an excessive systemic inflammation response with dysfunction of endothelial. Our study was to investigate the association between genetic variations in IL-1 and the susceptibility to PE in Chinese Han population. 402 PE patients and 554 normal pregnant women of third trimester were enrolled. The polymorphisms of rs315952 in IL1RN and rs17561 in IL1A were genotyped by TaqMan allelic discrimination real-time PCR. Obviously statistic difference of the genotypic frequencies were found in both of IL1RN rs315952 and IL1A rs17561 between cases and controls (for rs315952, P = 0.001; for rs17561, P = 0.021.). For rs315952, the C allele was associated with development of PE (P = 0.003, OR = 1.319, 95%CI 1.099–1.583). Patients with CC or CT genotype were less likely to develop severe PE than patients carrying TT genotype(P < 0.001, OR = 0.24, 95%CI 0.15–0.40). For rs17561, the C allele was the risk factor for predisposition to PE (P = 0.012, OR = 1.496, 95%CI 1.089–2.055). Our results suggest IL1RN and IL1A may involve in the development of PE in Chinese Han population.

Genotypes and phenotypes of congenital goitre and hypothyroidism caused by mutations in dual oxidase 2 genes.

The aim of this study was to screen for DUOX2, TPO and TG mutations in Chinese patients with congenital hypothyroidism (CH) and goitre and to define the relationships between DUOX2 genotypes and clinical phenotypes.

Screening of PAX8 mutations in Chinese patients with congenital hypothyroidism.

Background: Congenital hypothyroidism (CH) is a neonatal endocrine disease with an incidence of 1:2000 to 1:4000 worldwide. In about 85% of patients CH is secondary to thyroid dysgenesis, but its pathogenesis remains unclear. Thyroid transcription factors, such as paired box transcription factor 8 (PAX8), play an important role in thyroid organogenesis and development. Aim: To screen PAX8 mutations in Chinese CH patients and characterize the features of PAX8 mutations in China. Materials and methods: Blood samples were collected from 300 CH patients in Shandong Province, China, and genomic DNA was extracted from peripheral blood leukocytes. Using PCR and direct sequencing, exon 3 and exon 4 of PAX8 were analyzed. Results: Analysis of PAX8 in 300 CH patients revealed heterozygous missense mutations or variations in two unrelated patients; one was a known missense mutation G92A, resulting in an arginine to histidine substitution at codon 31, the other was a missense variation G122T, resulting in the substitution of a glycine at position 41 by a valine residue. The patient with the R31H mutation had CH with thyroid hypoplasia, while the patient with the G41V variation had CH with a eutopic and normal-sized thyroid gland. Conclusion: We report a heterozygous missense mutation and a variation in PAX8 in two out of 300 unrelated Chinese CH patients, showing that the PAX8 mutation rate is very low in CH patients in China.

IL-8 –251T/A and IL-12B 1188A/C polymorphisms are associated with gout in a Chinese male population

Objectives: Gout is caused by monosodium urate (MSU) crystal-induced inflammation of the joints and periarticular tissues. MSU crystals activate NALP3 and mediate interleukin (IL)-1β generation from its inactive pro-form, resulting in cellular activation and an IL-8-mediated neutrophil influx into the joint. IL-8 and IL-12 are important chemokines related to the initiation and amplification of acute and chronic inflammatory processes. In this study, we investigated whether the IL-8 –251T/A and IL-12 1188A/C polymorphisms are associated with susceptibility to gout in a Chinese Han male population. Methods: Overall, 387 patients with gout and 576 controls were included in this study. Genotyping was performed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). An association analysis was carried out using the χ2 test. A genotype–phenotype analysis was also conducted. Results: The T allele of IL-8 –251 was associated with risk of gout [p = 0.031 (odds ratio (OR) 1.229, 95% confidence interval (CI) 1.019–1.483]. There was a clear link between the IL-12 1188 AA and AC genotypic and A allelic frequencies between gout cases and controls (p < 0.001, df = 2 by genotype; p < 0.001, OR 1.404, 95% CI 1.165–1.691 by allele). Conclusions: Our results suggest that the IL-8 –251T/A and IL-12B 1188A/C polymorphisms may be relevant host susceptibility factors for the development of gout.

Polymorphisms in the Presumptive Promoter Region of the SLC2A9 Gene Are Associated with Gout in a Chinese Male Population

Background Glucose transporter 9 (GLUT9) is a high-capacity/low-affinity urate transporter. To date, several recent genome-wide association studies (GWAS) and follow-up studies have identified genetic variants of SLC2A9 associated with urate concentrations and susceptibility to gout. We therefore investigated associations between gout and polymorphisms and haplotypes in the presumptive promoter region of GLUT9 in Chinese males. Methodology/Principal Findings The approximately 2000 bp presumptive promoter region upstream of the start site of exon 1 of GLUT9 was sequenced and subjected to genetic analysis. A genotype-phenotype correlation was performed and polymorphisms-induced changes in transcription factor binding sites were predicted. Of 21 SNPs identified in GLUT9, five had not been previously reported. Two of the SNPs (rs13124007 and rs6850166) were associated with susceptibility to gout (p = 0.009 and p = 0.042, respectively). The C allele of rs13124007 appeared to be the risk allele for predisposition to gout (p = 0.006, OR 1.709 [95% CI 1.162–2.514]). For rs6850166, an increased risk of gout was associated with the A allele (p = 0.029, OR 1.645 [95% CI 1.050–2.577]). After Bonferroni correction, there was statistically difference in rs13124007 allele frequencies between gout cases and controls (P = 0.042). Haplotype analyses showed that haplotype GG was a protective haplotype (p = 0.0053) and haplotype CA was associated with increased risk of gout (p = 0.0326). Genotype-phenotype analysis among gout patients revealed an association of rs13124007 with serum triglycerides levels (P = 0.001). The C to G substitution in polymorphism rs13124007 resulted in a loss of a binding site for transcription factor interferon regulatory factor 1 (IRF-1). Conclusions/Significance Polymorphisms rs13124007 and rs6850166 are associated with susceptibility to gout in Chinese males.

Interleukin-1β-31C/T and -511T/C Polymorphisms Were Associated with Preeclampsia in Chinese Han Population

Objective The purpose of our study is to investigate the relationship between IL-1β -31C/T (rs1143627) and -511T/C (rs16944) polymorphisms and the preeclampsia (PE), and analyze the Linkage disequilibrium (LD) and haplotype frequency of the two polymorphism loci. Methods Polymorphisms at -31C/T and -511T/C of IL-1β were genotyped with the method of polymerase chain reaction-restriction fragment length polymorphism (PCR- RFLP) in 232 PE and 447 control subjects. Genotype and allele frequencies between case-control groups were compared by chi-square(X2) tests. Two-point LD and haplotype frequency analyses were done with the software Haploview4.2. Results Significant statistical differences were found between PE and control groups regarding genotype and allele frequencies of the two polymorphisms of IL-1β (For IL-1β -31C/T: X2 = 11.478, P = 0.003; For IL-1β-511T/C: X2 = 9.687, P = 0.008). LD analysis revealed that the IL-1β -31C/T SNP was in high LD with the IL-1β-511C/T SNP(D′ = 0.92, r2 = 0.79). Both CT and TC haplotypes showed significant differences between case and control groups. Only the plasma level of Prothrombin Time had a significantly statistical difference among TT, CT and CC groups of the preeclamptic two polymorphisms of IL-1β-31C/T and -511T/C (for IL-1β-31C/T, F = 1.644, P = 0.01; F = 1.587, P = 0.016). Conclusion Our results revealed IL-1β was associated with the PE in Chinese Han population. The CT haplotype may increase the risk of PE, while haplotype TC could be considered as a protective haplotype of PE.

CFC1 mutations in Chinese children with congenital heart disease

BACKGROUND Congenital heart disease (CHD) is one of the most common human birth defects. Over the last few decades, a variety of CHD-causing gene mutations have been identified. The aim of this study was to identify potential pathological mutations in the Cryptic (CFC1) gene in 500 Chinese children with CHD and to gain insight into the etiology of CHD. METHOD Sequence analysis of CFC1 in 500 non-syndromic CHD patients and 250 healthy controls. RESULT We identified three novel non-synonymous variants (c. G506T p. Gly169Val; c. G517A p. Gly173Arg; c. G658T p. Leu219Phe). These variants were not observed in 250 controls. All of the non-synonymous variants were located in or very close to the hydrophobic C-terminus. CONCLUSIONS To our knowledge, this is the first study to suggest that CFC1 may be involved in the etiology of non-syndromic CHD in a Chinese population.