Association of DCDC2 Polymorphisms with Normal Variations in Reading Abilities in a Chinese Population

The doublecortin domain-containing 2 (DCDC2) gene, which is located on chromosome 6p22.1, has been widely suggested to be a candidate gene for dyslexia, but its role in typical reading development over time remains to be clarified. In the present study, we explored the role of DCDC2 in contributing to the individual differences in reading development from ages 6 to 11 years by analysing data from 284 unrelated children who were participating in the Chinese Longitudinal Study of Reading Development (CLSRD). The associations of eight single nucleotide polymorphisms (SNPs) in DCDC2 with the latent intercept and slope of children’s reading scores were examined in the first step. There was significant support for an association of rs807724 with the intercept for the reading comprehension measure of reading fluency, and the minor “G” allele was associated with poor reading performance. Next, we further tested the rs807724 SNP in association with the reading ability at each tested time and revealed that, in addition to significant associations with the two main reading measures (reading fluency and Chinese character reading) over multiple testing occasions, this SNP also showed associations with reading-related cognitive skills, including morphological production, orthographic judgment and phonological processing skills (rapid number naming, phoneme deletion, and tone detection). This study provides support for DCDC2 as a risk gene for reading disability and suggests that this gene is also operative for typical reading development in the Han population.     

Association of RAC1 Gene Polymorphisms with Primary End-Stage Renal Disease in Chinese Renal Recipients

Background/Objective

RAC1 gene could influence susceptibility to renal failure by altering the activity and expression of Rac1, which is a member of the Rho family of small GTP-binding proteins. In clinical practice, renal transplantation provides the optimal treatment for people with end-stage renal disease (ESRD). The objective of this present study was to determine whether the RAC1 gene polymorphisms were associated with primary ESRD susceptibility in Chinese renal recipients.

Methods

Six single nucleotide polymorphisms (SNPs) of RAC1 gene, including rs836488 T>C, rs702482 A>T, rs10951982 G>A, rs702483 A>G, rs6954996 G>A, and rs9374 G>A, were genotyped in 300 renal transplant recipients (cases) and 998 healthy Chinese subjects (controls) by using TaqMan SNP genotyping assay. Allele, genotype, and haplotype frequencies of the six SNPs were compared between cases and controls. Odds ratios (OR) and 95% confidence intervals (CI) were calculated in logistic regression models to evaluate the associations of the six SNPs with ESRD risk.

Results

The genotype distributions for the six SNPs in controls were consistent with Hardy-Weinberg equilibrium (P > 0.05). Association analysis revealed that three SNPs were significantly associated with ESRD risk. Positive associations with ESRD risk were found for the rs836488, rs702482, and rs702483 in the co-dominant model (minor allele homozygotes versus major allele homozygotes); specifically, the frequencies of the minor allele homozygotes and the minor allele for the three SNPs were higher in the cases than in the controls. In addition, these three SNPs also had associations with increased ESRD risk under the additive model (P < 0.05), and positive associations were also found for the rs836488 in the dominant model (P < 0.05) and for the rs702483 in the recessive model (P < 0.05). All these associations were independent of confounding factors. The other three SNPs (rs10951982, rs6954996, and rs9374), in all comparison models, were not associated with ESRD risk (P > 0.05). In haplotype analysis, carriers with "C-T-G-G-G-G" haplotype had a significantly higher risk of ESRD compared with the most common haplotype "T-A-G-A-G-G" (P = 0.011, OR = 1.46, 95% CI = 1.09–1.94).

Conclusion

This study suggested that polymorphisms of RAC1 gene might influence the susceptibility to ESRD in Chinese Han population. Further studies are necessary to confirm our findings.     

Association of Genetic Markers in the BCL-2 Family of Apoptosis-Related Genes with Endometrial Cancer Risk in a Chinese Population

BackgroundIn vitro studies have demonstrated the role of the BCL-2 family of genes in endometrial carcinogenesis. The role of genetic variants in BCL-2 genes and their interactions with non-genetic factors in the development of endometrial cancer has not been investigated in epidemiological studies.ResultsSignificant associations with endometrial cancer risk were found for 9 SNPs in the BCL2 gene (P trend<0.05 for all). For SNPs rs17759659 and rs7243091 (minor allele for both: G), the associations were independent. The odds ratio was 1.27 (95% CI: 1.04–1.53) for women with AG genotype for the SNP rs17759659 and 1.82 (95% CI: 1.21–2.73) for women with the GG genotype for the SNP rs7243091. No interaction between these two SNPs and established non-genetic risk factors of endometrial cancer was noticed.ConclusionGenetic polymorphisms in the BCL2 gene may be associated with the risk of endometrial cancer in Chinese women.     

Genetic Variation in NFKB1 and NFKBIA and Susceptibility to Coronary Artery Disease in a Chinese Uygur Population

Objectives

Coronary artery disease (CAD) is the most common chronic inflammatory disease worldwide. NF-κB, a central regulator of inflammation, is involved in various inflammatory diseases. The aim of this study was to investigate the association between NFKB1 and NFKBIA polymorphisms and the susceptibility to CAD and their impact on plasma levels of IL-6 in a Chinese Uygur population.

Methods

We genotyped NFKB1-94ins/del ATTG (rs28362491) and NFKBIA3’ UTR A/G (rs696) using TaqMan SNP genotyping assays in 960 Uygur CAD cases and Uygur 1060 CAD-negtive controls. IL-6 plasma levels were measured in 360 stable angina pectoris (SAP) cases and 360 controls using ELISA method.

Results

There was no significant difference in the distribution of the genotypes and alleles of rs696 polymorphism in CAD cases and controls. Significant difference in the frequency of genotypes (P = 0.001) and alleles (P = 0.001) of rs28362491 polymorphism was observed in CAD cases compared to controls. In multivariate logistic regression analysis, SNP rs28362491 was consistently associated with CAD risk in a recessive model after adjustment for cardiovascular risk factors (OR = 1.581, 95% CI 1.222 to 2.046, P<0.001). SAP cases had significantly higher plasma levels of IL-6 compared to controls (P<0.001). General linear model analysis showed rs28362491 was independently associated with increased IL-6 levels by analyses of a recessive model (P<0.001) after adjustment for covariates.

Conclusions

Our study indicates that NFKB1-94 ins/del ATTG polymorphism may play a role in CAD susceptibility in Chinese Uygur population and is functionally associated with IL-6 expression, suggesting a mechanistic link between NFKB1-94 ins/del ATTG polymorphism and CAD susceptibility.     

Polymorphism of rs873308 near the transmembrane protein 57 gene is associated with serum lipid levels

SNP (single-nucleotide polymorphism) of rs10903129 near the TMEM (transmembrane protein) 57 locus has been associated with TC (total cholesterol) in a previous GWAS (genome-wide association study), but the association of TMEM57 rs873308 SNP and serum lipid levels has not been previously reported. The current study was undertaken to detect the association of the TMEM57 rs873308 SNP and several environmental factors with serum lipid profiles in the Han Chinese and Mulao populations. The genotypes of the TMEM57 rs873308 SNP in 865 individuals of Han Chinese and 902 participants of Mulao nationality were determined by PCR and RFLP (restriction-fragment-length polymorphism) combined with gel electrophoresis and then confirmed by direct sequencing. The T allele frequency of TMEM57 rs873308 SNP was not different between Han and Mulao (23.18% versus 25.72%, P>0.05), but different between males and females in the two ethnic groups (P<0.05). The T allele carriers had lower serum TC, Apo (apolipoprotein) B, HDL-C (high-density lipoprotein cholesterol) levels, ApoA1/ApoB ratio in Han; and lower TAG (triacylglycerol), LDL-C (low-density lipoprotein cholesterol), ApoA1 levels and the ApoA1/ApoB ratio and higher HDL-C levels in Mulao than the T allele non-carriers. There was also different association of the TMEM57 rs873308 SNP and serum lipid profiles between males and females in the both ethnic groups. Serum lipid parameters in the two ethnic groups were also associated with several environmental factors. The association of the TMEM57 rs873308 SNP and serum lipid levels was different in the Han Chinese and Mulao populations and between males and females in the both ethnic groups. There may be a sex-specific association of the TMEM57 rs873308 SNP and serum lipid levels in our study populations.     

Evaluating GWAS-Identified SNPs for Age at Natural Menopause among Chinese Women

Background

Age at natural menopause (ANM) is a complex trait with high heritability and is associated with several major hormonal-related diseases. Recently, several genome-wide association studies (GWAS), conducted exclusively among women of European ancestry, have discovered dozens of genetic loci influencing ANM. No study has been conducted to evaluate whether these findings can be generalized to Chinese women.

Methodology/Principal Findings

We evaluated the index single nucleotide polymorphisms (SNPs) in 19 GWAS-identified genetic susceptibility loci for ANM among 3,533 Chinese women who had natural menopause. We also investigated 3 additional SNPs which were in LD with the index SNP in European-ancestry but not in Asian-ancestry populations. Two genetic risk scores (GRS) were calculated to summarize SNPs across multiple loci one for all SNPs tested (GRSall), and one for SNPs which showed association in our study (GRSsel). All 22 SNPs showed the same association direction as previously reported. Eight SNPs were nominally statistically significant with P≤0.05: rs4246511 (RHBDL2), rs12461110 (NLRP11), rs2307449 (POLG), rs12611091 (BRSK1), rs1172822 (BRSK1), rs365132 (UIMC1), rs2720044 (ASH2L), and rs7246479 (TMEM150B). Especially, SNPs rs4246511, rs365132, rs1172822, and rs7246479 remained significant even after Bonferroni correction. Significant associations were observed for GRS. Women in the highest quartile began menopause 0.7 years (P = 3.24×10⁻⁹) and 0.9 years (P = 4.61×10⁻¹¹) later than those in the lowest quartile for GRSsel and GRSall, respectively.

Conclusions

Among the 22 investigated SNPs, eight showed associations with ANM (P<0.05) in our Chinese population. Results from this study extend some recent GWAS findings to the Asian-ancestry population and may guide future efforts to identify genetic determination of menopause.     

Study of Five Pubertal Transition-Related Gene Polymorphisms as Risk Factors for Premature Coronary Artery Disease in a Chinese Han Population

Background

Recently, single nucleotide polymorphisms (SNPs) (DLK-rs10144321, SIX6-rs1254337, MKRN3-rs12148769, LIN28B-rs7759938, and KCNK9-rs1469039) were found to be strongly associated with age at menarche. Recent studies also suggested that age at menarche is a heritable trait and is associated with risks for obesity, type 2 diabetes mellitus (T2DM), cardiovascular disease, and all-cause mortality. Since an association between these five SNPs and premature coronary artery disease (CAD) has never been reported, we investigated whether these SNPs are associated with premature CAD and its severity in a Chinese Han population.

Methods

We enrolled 432 consecutive patients including 198 with premature CAD (<55 years in men and <65 years in women) and 234 controls. All subjects were genotyped for the five SNPs by the PCR-ligase detection reaction method. The associations between these SNPs and premature CAD and its severity were analyzed.

Results

The following genotypes were identified: GG, AG, and AA at rs10144321 and rs12148769; TT, AT, and AA at rs1254337; CC, CT, and TT at rs1469039; and TT and CT at rs7759938. Significant differences in genotype distribution frequencies at rs1254337 were found between controls and patients with premature CAD (P<0.05). No associations were found between the five SNPs and the severity of coronary lesions (all P>0.05). Compared with controls, patients with premature CAD had a higher prevalence of T2DM and dyslipidemia, and the proportion of patients with T2DM rose significantly with an increase in the number of stenosed coronary vessels (all P<0.05). After adjustment for the clinical parameters in multivariable analysis, three factors were identified that significantly increased the risk of premature CAD: the AA genotype at rs1254337 (OR: 2.388, 95% CI: 1.190–4.792, P = 0.014), male gender (OR: 1.565, 95% CI: 1.012–2.420, P = 0.044), and T2DM (OR 2.252, 95% CI: 1.233–4.348, P = 0.015).

Conclusions

Among the five pubertal transition-related gene polymorphisms, we identified an association between rs1254337 and premature CAD in a Chinese Han population.     

A Newfound Association between MDC1 Functional Polymorphism and Lung Cancer Risk in Chinese

Mediator of DNA damage checkpoint protein 1 (MDC1) plays an early and core role in Double-Strand Break Repair (DDR) and ataxia telangiectasia-mutated (ATM) mediated response to DNA double-strand breaks (DSBs), and thus involves the pathogenesis of several DNA damage-related diseases such as cancer. We hypothesized that the single nucleotide polymorphisms (SNPs) of MDC1 which have potencies on affecting MDC1 expression or function were associated with risk of lung cancer. In a two-stage case-control study, we tested the association between 5 putatively functional SNPs of MDC1 and lung cancer risk in a southern Chinese population, and validated the promising association in an eastern Chinese population. We found the SNP rs4713354A>C that is located in the 5′-untranslated region of MDC1 was significantly associated with lung cancer risk in both populations (P = 0.024), with an odds ratio as 1.23(95% confidence interval  = 1.35–1.26) for the rs4713354C (CA+CC) genotypes compared to the rs4713354AA genotype. However, no significant association was observed between other SNPs and lung cancer risk. The gene-based analysis rested with these SNPs suggested the MDC1 as a susceptible gene for lung cancer (P = 0.009). Moreover, by querying the gene expression database, we further found that the rs4713354C genotypes confer a significantly lower mRNA expression of MDC1 than the rs4713354AA genotype in 260 cases of lymphoblastoid cells (P = 0.002). Our data suggested that the SNP rs4713354A>C of MDC1 may be a functional genetic biomarker for susceptibility to lung cancer in Chinese.     

Targeting 160 Candidate Genes for Blood Pressure Regulation with a Genome-Wide Genotyping Array

The outcome of Genome-Wide Association Studies (GWAS) has challenged the field of blood pressure (BP) genetics as previous candidate genes have not been among the top loci in these scans. We used Affymetrix 500K genotyping data of KORA S3 cohort (n = 1,644; Southern-Germany) to address (i) SNP coverage in 160 BP candidate genes; (ii) the evidence for associations with BP traits in genome-wide and replication data, and haplotype analysis. In total, 160 gene regions (genic region±10 kb) covered 2,411 SNPs across 11.4 Mb. Marker densities in genes varied from 0 (n = 11) to 0.6 SNPs/kb. On average 52.5% of the HAPMAP SNPs per gene were captured. No evidence for association with BP was obtained for 1,449 tested SNPs. Considerable associations (P<10⁻³) were detected for the genes, where >50% of HAPMAP SNPs were tagged. In general, genes with higher marker density (>0.2 SNPs/kb) revealed a better chance to reach close to significance associations. Although, none of the detected P-values remained significant after Bonferroni correction (P<0.05/2319, P<2.15×10⁻⁵), the strength of some detected associations was close to this level: rs10889553 (LEPR) and systolic BP (SBP) (P = 4.5×10⁻⁵) as well as rs10954174 (LEP) and diastolic BP (DBP) (P = 5.20×10⁻⁵). In total, 12 markers in 7 genes (ADRA2A, LEP, LEPR, PTGER3, SLC2A1, SLC4A2, SLC8A1) revealed considerable association (P<10⁻³) either with SBP, DBP, and/or hypertension (HYP). None of these were confirmed in replication samples (KORA S4, HYPEST, BRIGHT). However, supportive evidence for the association of rs10889553 (LEPR) and rs11195419 (ADRA2A) with BP was obtained in meta-analysis across samples stratified either by body mass index, smoking or alcohol consumption. Haplotype analysis highlighted LEPR and PTGER3. In conclusion, the lack of associations in BP candidate genes may be attributed to inadequate marker coverage on the genome-wide arrays, small phenotypic effects of the loci and/or complex interaction with life-style and metabolic parameters.     

Pathway-Based Genome-Wide Association Studies for Plasma Triglycerides in Obese Females and Normal-Weight Controls

Pathway-based analysis as an alternative approach can provide complementary information to single-marker genome-wide association studies (GWASs), which always ignore the epistasis and does not have sufficient power to find rare variants. In this study, using genotypes from a genome-wide association study (GWAS), pathway-based association studies were carried out by a modified Gene Set Enrichment Algorithm (GSEA) method (GenGen) for triglyceride in 1028 unrelated European-American extremely obese females (BMI≥35kg/m²) and normal-weight controls (BMI<25kg/m²), and another pathway association analysis (ICSNPathway) was also used to verify the GenGen result in the same data. The GO0009110 pathway (vitamin anabolism) was among the strongest associations with triglyceride (empirical P<0.001); the result remained significant after FDR correction (P = 0.022). MMAB, an obesity-related locus, included in this pathway. The ABCG1 and BCL6 gene was found in several triglyceride-related pathways (empirical P<0.05), which were also replicated by ICSNPathway (empirical P<0.05, FDR<0.05). We also performed single-marked GWAS using PLINK for TG levels (log-transformed). Significant associations were found between ASTN2 gene SNPs and plasma triglyceride levels (rs7035794, P = 2.24×10⁻¹⁰). Our study suggested that vitamin anabolism pathway, BCL6 gene pathways and ASTN2 gene may contribute to the genetic variation of plasma triglyceride concentrations.     

Interferon-Inducible Transmembrane Protein 3 Genetic Variant rs12252 and Influenza Susceptibility and Severity: A Meta-Analysis

BackgroundThe pandemic influenza A (H1N1) pdm09 virus, avian influenza A (H5N1) virus, and influenza A (H7N9) virus induced severe morbidity and mortality throughout the world. Previous studies suggested a close association between the interferon-induced transmembrane protein-3 (IFITM3) genetic variant rs12252 and influenza. Here, we explored the correlation between the rs12252 and influenza susceptibility and severity using meta-analysis.MethodsRelevant studies published before May 22, 2014 were retrieved from PubMed, ISI web of knowledge, EBSCO, and Cochrane central register of controlled trials databases. Association between rs12252 and influenza susceptibility and severity were determined using statistical analysis of odds ratios (ORs).ResultsA total of four studies consisting of 445 cases and 4180 controls were included in our analysis. Generally, there is increased risk of influenza in subjects carrying rs12252 in the recessive model (CC vs. CT+TT: OR = 2.35, 95% CI: 1.49-3.70, P<0.001), the dominant model (CC+CT vs. TT: OR=1.60, 95% CI: 1.18–2.22, P=0.003), the homozygote comparison (CC vs. TT: OR=4.11, 95% CI: 2.15–7.84, P<0.001), and the allele contrast (C vs. T: OR=1.67, 95% CI: 1.32–2.13, P<0.001). Stratification analysis of ethnicity and severity revealed a significant increase in influenza susceptibility by IFITM3-SNP rs12252 among both Asian and Caucasian population. SNP rs12252 shows significant impact on severe infections (P<0.05), but not on mild influenza. Besides, our result also associated rs12252 with influenza severity (severe vs. mild: OR=2.37, 95% CI: 1.32–4.25, P=0.004), (severe vs. control: OR=2.70, 95% CI: 1.85–3.94, P<0.001).ConclusionOur meta-analysis suggests a significant association between a minor IFITM3 allele (SNP rs12252-C) with severe influenza susceptibility, but not in mild influenza subjects, in both UK Caucasians and Han Chinese population. The rs12252-C allele causes a 23.7% higher chance of infection and also constitutes a risk factor for more severe influenza.     

APOBEC3G Variants and Protection against HIV-1 Infection in Burkina Faso

Studies on host factors, particularly the APOBEC3G gene, have previously found an association with AIDS progression in some populations and against some HIV-1 strains but not others. Our study had two main objectives: firstly, to screen a population from Burkina Faso for three variants of APOBEC3G previously described, and secondly to analyze the effect of these three variants and their haplotypes on HIV-1 infection with Circulating Recombinant Forms (CRFs) present in Burkina Faso. This case control study involved 708 seropositive and seronegative individuals. Genotyping was done by the TaqMan allelic discrimination method. Minor allele frequencies of rs6001417 (p<0.05), rs8177832 (P<0.05), and rs35228531 (P<0.001) were higher in seronegative subjects. The rs6001417 and rs8177832 SNPs were associated with HIV-1 infection in an additive model (P<0.01). Furthermore the SNP rs35228531 was also associated with HIV-1 infection in a dominant model (P<0.001). Odds ratio analysis of genotypes and alleles of the different APOBEC3G variants showed that there is a strong association between the minor genetic variants, genotype of the three SNPs, and HIV-1 status. Haplotype analysis demonstrated that rs6001417, rs8177832, and rs35228531 are in linkage disequilibrium. The haplotype GGT from the rs6001417, rs8177832 and rs35228531 respectively has a protective effect OR = 0.54 [0.43–0.68] with P<0.001. There was also associations between the haplotypes GGC OR = 1.6 [1.1;-2.3] P<0.05, and CGC OR = 5.21 [2.4–11.3] P<0.001, which increase the risk of infection by HIV-1 from almost two (2) to five (5) fold. This study demonstrates an association of rs6001417, rs8177832, and rs35228531 of APOBEC3G with HIV-1 infection in a population from Burkina Faso.     

Age- and Sex-Dependent Association between FTO rs9939609 and Obesity-Related Traits in Chinese Children and Adolescents

Background

The associations between common variants in the fat mass- and obesity-associated (FTO) gene and obesity-related traits may be age-dependent and may differ by sex. The present study aimed to assess the association of FTO rs9939609 with body mass index (BMI) and the risk of obesity from childhood to adolescence, and to determine the age at which the association becomes evident.

Methods

Totally 757 obese and 2,746 non-obese Chinese children aged 6–18 years were genotyped for FTO rs9939609. Of these, a young sub-cohort (n = 777) aged 6–11 years was reexamined 6 years later. Obesity was defined using the sex- and age-specific BMI cut-offs recommended by the International Obesity Task Force.

Results

The associations of FTO rs9939609 with BMI and obesity did not appear until children reached 12–14 years. The variant was associated with an increased BMI in boys (β = 1.50, P = 0.004) and girls (β = 0.97, P = 0.018), respectively. Thereafter, the magnitude of association increased in girls at ages 15–18 years (β = 2.02, P<0.001), but not boys (β = 0.10, P>0.05). Age was found to interact with the variant on BMI (P<0.001) and obesity (P = 0.042) only in girls. In the sub-cohort, the associations of FTO rs9939609 with BMI (β = 1.07, P = 0.008) and obesity (OR = 2.09, 95% CI: 1.12, 3.91) were only observed 6 years later (ages 12–18 years) in girls, even after adjusting for baseline BMI.

Conclusions

The association between FTO rs9939609 and obesity-related traits may change from childhood to adolescence in Chinese individuals, and the association may start as early as age 12 years, especially in girls.     

Single Nucleotide Polymorphism 8q24 rs13281615 and Risk of Breast Cancer: Meta-Analysis of More than 100,000 Cases

Background

The onset and progression of breast cancer (BC) is influenced by many factors, including the single nucleotide polymorphism (SNP) rs13281615 at 8q24. However, studies of the potential association between rs13281615 at 8q24 and risk of BC have given inconsistent results. We performed a meta-analysis to address this controversy.

Methods

PubMed, EMBASE and the Chinese National Knowledge Infrastructure databases were systematically searched to identify relevant studies. Two curators independently extracted data, and odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated to assess the strength of the association between rs13281615 at 8q24 and risk of BC.

Results

Fourteen studies are included in the meta-analysis, involving 44,283 cases (5,170 Chinese and 39,113 mixed) and 55,756 controls (5,589 Chinese and 50,167 mixed). The GG and G-allele genotypes of rs13281615 at 8q24 are significantly associated with increased risk of BC (GG vs. AG+AA, OR 1.13, 95% CI 1.08–1.19, P<0.001; G-allele vs. A-allele, OR 1.10, 95% CI 1.06–1.14, P<0.001; GG vs. AA, OR 1.20, 95% CI 1.12–1.29, P<0.001). Conversely, the AA genotype is significantly associated with decreased risk of BC (AA vs. AG+GG, OR 0.89, 95% CI 0.84–0.93, P<0.001).

Conclusion

G-allele genotypes of rs13281615 at 8q24 polymorphism are a risk factor for developing BC, while the AA genotype is a protective factor. Further large and well-designed studies are required to confirm this conclusion.     

Ancestry-Shift Refinement Mapping of the C6orf97-ESR1 Breast Cancer Susceptibility Locus

We used an approach that we term ancestry-shift refinement mapping to investigate an association, originally discovered in a GWAS of a Chinese population, between rs2046210[T] and breast cancer susceptibility. The locus is on 6q25.1 in proximity to the C6orf97 and estrogen receptor α (ESR1) genes. We identified a panel of SNPs that are correlated with rs2046210 in Chinese, but not necessarily so in other ancestral populations, and genotyped them in breast cancer case∶control samples of Asian, European, and African origin, a total of 10,176 cases and 13,286 controls. We found that rs2046210[T] does not confer substantial risk of breast cancer in Europeans and Africans (OR = 1.04, P = 0.099, and OR = 0.98, P = 0.77, respectively). Rather, in those ancestries, an association signal arises from a group of less common SNPs typified by rs9397435. The rs9397435[G] allele was found to confer risk of breast cancer in European (OR = 1.15, P = 1.2×10⁻³), African (OR = 1.35, P = 0.014), and Asian (OR = 1.23, P = 2.9×10⁻⁴) population samples. Combined over all ancestries, the OR was 1.19 (P = 3.9×10⁻⁷), was without significant heterogeneity between ancestries (P_het = 0.36) and the SNP fully accounted for the association signal in each ancestry. Haplotypes bearing rs9397435[G] are well tagged by rs2046210[T] only in Asians. The rs9397435[G] allele showed associations with both estrogen receptor positive and estrogen receptor negative breast cancer. Using early-draft data from the 1,000 Genomes project, we found that the risk allele of a novel SNP (rs77275268), which is closely correlated with rs9397435, disrupts a partially methylated CpG sequence within a known CTCF binding site. These studies demonstrate that shifting the analysis among ancestral populations can provide valuable resolution in association mapping.     

Candidate Gene Association Analysis of Neuroblastoma in Chinese Children Strengthens the Role of LMO1

Neuroblastoma (NB) is the most common extra-cranial solid tumor in children and the most frequently diagnosed cancer in the first year of life. Previous genome-wide association studies (GWAS) of Caucasian and African populations have shown that common single nucleotide polymorphisms (SNPs) in several genes are associated with the risk of developing NB, while few studies have been performed on Chinese children. Herein, we examined the association between the genetic polymorphisms in candidate genes and the risk of NB in Chinese children. In total, 127 SNPs in nine target genes, revealed by GWAS studies of other ethnic groups and four related lincRNAs, were genotyped in 549 samples (244 NB patients and 305 healthy controls). After adjustment for gender and age, there were 21 SNPs associated with NB risk at the two-sided P < 0.05 level, 11 of which were located in LMO1. After correction for multiple comparisons, only rs204926 in LMO1 remained significantly different between cases and controls (OR = 0.45, 95% CI: 0.31–0.65, adjusted P = 0.003). In addition, 16 haplotypes in four separate genes were significantly different between case and control groups at an unadjusted P value < 0.05, 11 of which were located in LMO1. A major haplotype, ATC, containing rs204926, rs110420, and rs110419, conferred a significant increase in risk for NB (OR = 1.82, 95% CI: 1.41–2.36, adjusted P < 0.001). The major finding of our study was obtained for risk alleles within the LMO1 gene. Our data suggest that genetic variants in LMO1 are associated with increased NB risk in Chinese children.     

Comprehensive Linkage and Association Analyses Identify Haplotype, Near to the TNFSF15 Gene, Significantly Associated with Spondyloarthritis

Spondyloarthritis (SpA) is a chronic inflammatory disorder with a strong genetic predisposition dominated by the role of HLA-B27. However, the contribution of other genes to the disease susceptibility has been clearly demonstrated. We previously reported significant evidence of linkage of SpA to chromosome 9q31–34. The current study aimed to characterize this locus, named SPA2. First, we performed a fine linkage mapping of SPA2 (24 cM) with 28 microsatellite markers in 149 multiplex families, which allowed us to reduce the area of investigation to an 18 cM (13 Mb) locus delimited by the markers D9S279 and D9S112. Second, we constructed a linkage disequilibrium (LD) map of this region with 1,536 tag single-nucleotide polymorphisms (SNPs) in 136 families (263 patients). The association was assessed using a transmission disequilibrium test. One tag SNP, rs4979459, yielded a significant P-value (4.9×10⁻⁵). Third, we performed an extension association study with rs4979459 and 30 surrounding SNPs in LD with it, in 287 families (668 patients), and in a sample of 139 cases and 163 controls. Strong association was observed in both familial and case/control datasets for several SNPs. In the replication study, carried with 8 SNPs in an independent sample of 232 cases and 149 controls, one SNP, rs6478105, yielded a nominal P-value<3×10⁻². Pooled case/control study (371 cases and 312 controls) as well as combined analysis of extension and replication data showed very significant association (P<5×10⁻⁴) for 6 of the 8 latter markers (rs7849556, rs10817669, rs10759734, rs6478105, rs10982396, and rs10733612). Finally, haplotype association investigations identified a strongly associated haplotype (P<8.8×10⁻⁵) consisting of these 6 SNPs and located in the direct vicinity of the TNFSF15 gene. In conclusion, we have identified within the SPA2 locus a haplotype strongly associated with predisposition to SpA which is located near to TNFSF15, one of the major candidate genes in this region.     

The correlation of microRNA-499 rs3746444 T>C locus with the susceptibility of gastric cancer: from a case–control study to a meta-analysis

The relationship between rs3746444 T>C single-nucleotide polymorphism (SNP) in microRNA (mir)-499 and risk of gastric cancer (GC) has been widely investigated. However, the association was still unconfirmed. Here, we first recruited 490 GC patients and 1476 controls, and conducted a case-control study. And we did not find any association between rs3746444 T>C SNP polymorphism and risk of GC. Subsequently, we conducted a meta-analysis to explore the association of mir-499 rs3746444 polymorphism with GC development. Two authors searched the PubMed and EMBASE databases up to October 15, 2019 independently. Finally, nine literatures involving 12 independent studies were included. In total, 3954 GC cases and 9745 controls were recruited for meta-analysis. The results suggested that allele model, homozygote model and recessive model could increase the risk of overall GC (P = 0.002, 0.009 and 0.013, respectively). When we excluded the studies violated HWE, this association was also found in allele model (P = 0.020) and dominant model (P= 0.044). In subgroup analyses, we identified that rs3746444 SNP in mir-499 increased the risk of GC in Asians and gastric cardiac adenocarcinoma (GCA) subgroups. No significant bias of selection was found (all P>0.1). Test of sensitivity analysis indicated that our findings were stable. Additionally, we found that the power value was 0.891 in the allele model, suggesting the reliability of our findings. In summary, our analysis confirmed the association between rs3746444 and the risk of GC, especially in Asians and in patients with GCA.