Genotype frequency and F ST analysis of polymorphisms in immunoregulatory genes in Chinese and Caucasian populations

Single nucleotide variants in microRNA biosynthesis genes in Mexican individuals

Background: MicroRNAs (miRNAs) are important regulators in a variety of biological processes, and their dysregulation is associated with multiple human diseases. Single nucleotide variants (SNVs) in genes involved in the processing of microRNAs may alter miRNA regulation and could present high allele heterogeneity in populations from different ethnic groups. Thus, the aim of this study was to genotype 15 SNVs in eight genes involved in the miRNA processing pathway in Mexican individuals and compare their frequencies across 21 populations from five continental groups.

Methods: Genomic DNA was obtained from 399 healthy Mexican individuals. SNVs in AGO2 (rs2293939 and rs4961280), DGCR8 (rs720012), DICER (rs3742330 and rs13078), DROSHA (rs10719 and rs6877842), GEMIN3 (rs197388 and rs197414), GEMIN4 (rs7813, rs2740349, and rs4968104), TNRC6B (rs9611280), and XP05 (rs11077 and rs34324334) were genotyped using TaqMan probes. The minor allele frequency of each SNV was compared to those reported in the 1,000 Genomes database using chi-squared. Sankey plot was created in the SankeyMATIC package to visualize the frequency range of each variant in the different countries analyzed.

Results: In Mexican individuals, all 15 SNVs were found in Hardy-Weinberg equilibrium, with frequencies ranging from 0.04 to 0.45. The SNVs rs4961280, rs2740349, rs34324334, and rs720012 in Mexican individuals had the highest minor allele frequencies worldwide, whereas the minor allele frequencies of rs197388, rs10719, rs197414, and rs1107 were among the lowest in Mexican individuals. The variants had high allele heterogeneity among the sub-continental populations, ranging from monomorphic, as was the case for rs9611280 and rs34324334 in African groups, to >0.50, which was the case for variants rs11077 and rs10719 in most of the populations. Importantly, the variants rs197388, rs720012, and rs197414 had FST values > 0.18, indicating a directional selective process. Finally, the SNVs rs13078 and rs10719 significantly correlated with both latitude and longitude.

Conclusion: These data indicate the presence of high allelic heterogeneity in the worldwide distribution of the frequency of SNVs located in components of the miRNA processing pathway, which could modify the genetic susceptibility associated with human diseases in populations with different ancestry.

Investigation of the incidence trend of follicular lymphoma from 2008 to 2017 in Taiwan and the United States using population-based data

Background

The incidence of follicular lymphoma (FL) in Taiwan has not been well investigated since its inclusion as a histological subtype in the Taiwan Cancer Registry in 2008. The purpose of this study was to describe the incidence patterns of FL in Taiwan and compare the trends with those in other racial groups in the United States.

Materials and methods

We conducted an epidemiological study using population-based data from the Taiwan Cancer Registry, Ministry of Health and Welfare, and the 18 Surveillance, Epidemiology, and End Results (SEER) registries to evaluate the FL incidence from 2008 to 2017. We calculated the annual percent change (APC) to describe the trends in the incidence of FL in subpopulations defined by race and sex over time.

Results

The annual age-adjusted incidence rate of FL in Taiwan increased significantly from 0.59 per 100,000 persons in 2008 to 0.82 per 100,000 persons in 2017, with an APC of 3.2. By contrast, the incidence rate in whites in the United States during the same period decreased from 3.42 to 2.74 per 100,000 persons, with an APC of −2.1. We found no significant change for the blacks (APC, −1.5%), Hispanics (APC, −0.7%), and Asians or Pacific Islanders (APC, +0.7%). The temporal trend was similar between the males and females. The relative frequency of FL among the incident non-Hodgkin lymphoma (NHL) cases also increased significantly in Taiwan from 7.64% in 2008 to 11.11% in 2017 (APC = 3.8). The relative frequency of FL among the incident NHL cases in the whites decreased from 2008 to 2012 (APC, −3.8%) and then stabilized after 2012 (APC, −0.2%). By contrast, little change in relative frequency of FL among the incident NHL cases was observed in the blacks, Hispanics, and APIs between 2008 and 2017.

Conclusion

We found increases in the incidence of FL and the relative frequency of FL among the incident NHL cases in both males and females in Taiwan from 2008 to 2017. The FL incidence rates were unchanged for all races and sex groups in the United States, except for the decreases in the whites.

Association and interaction of the FTO rs1421085 with overweight/obesity in a sample of Pakistani individuals

PURPOSE

Genetic variants determine the predisposition of an individual to obesity in a given environment. The present study was conducted to seek an association of the FTO variant rs1421085 with overweight/obesity and related traits in 612 Pakistani subjects in a case-control manner (overweight/obese = 306 and non-obese = 306). Moreover, interaction effects of the rs1421085 and overweight/obesity on multiple metabolic traits were also investigated, which were never explored before in Pakistani as well as in any other population.

MATERIALS AND METHODS

Anthropometric traits were measured by standard procedures, while metabolic parameters were determined by biochemical assays. Genotyping of the rs1421085 was carried out by TaqMan allelic discrimination assay. The data were analysed using SPSS software version 19.

RESULTS

The study revealed a significant association of the rs1421085 with overweight/obese phenotype with respect to over-dominant model indicated by h-index. The CT genotype of the rs1421085 was observed to increase the risk of being overweight/obese by 1.583 times (95% CI 1.147-2.185, p = 0.005). The CT genotype was also found to be associated with higher values of all anthropometric variables (except height and waist-to-hip ratio). Moreover, the interaction between the CT genotype of the rs1421085 and overweight/obesity was found to influence several metabolic parameters (raised blood pressure, product of triglyceride and glucose index, triglyceride levels, LDL-C, VLDL-C, coronary risk index, atherogenic index, and triglyceride-to-HDL-C ratio).

CONCLUSION

In conclusion, the rs1421085 was found to be associated with overweight/obesity and related anthropometric traits independent of age and gender in Pakistani population. Moreover, this variant was found to influence various metabolic traits in the presence of overweight/obesity.

LEVEL OF EVIDENCE

Level III, case-control analytic study.

SCD rs41290540 single-nucleotide polymorphism modifies miR-498 binding and is associated with a decreased risk of coronary artery disease

Background

Atherosclerosis is the primary cause of coronary artery disease (CAD), and stearoyl‐CoA desaturase (SCD) is associated with atherosclerosis. However, the associations between variants of SCD and CAD have not yet been decided.

Methods

This study analyzed SCD rs41290540 single‐nucleotide polymorphism (SNP) in the 3′‐untranslated region for an association with a risk of CAD among the Chinese Han population. CAD patients and controls were genotyped for SNP rs41290540 in SCD by SNaPshot. The binding affinity of miR‐498 to rs41290540 was determined by a luciferase assay, and SCD expression was assessed using Western blot.

Results

A total of 969 CAD patients and 1,095 control subjects were involved in this study. The SCD rs41290540CC genotype is associated with a decreased risk of CAD compared with the AA genotype. Furthermore, the CC genotype is associated with lower serum total cholesterol (TC). Western blot analysis demonstrated that miR‐498 suppressed the expression of SCD. A luciferase assay confirmed that rs41290540 A>C variation in the SCD 3′UTR inhibits miR‐498 binding.

Conclusion

This study demonstrates that the SCD rs41290540 may be associated with a decreased risk of CAD, lower serum TC, and decreased miR‐498 binding.

The Association Between Schizophrenia Risk Variants and Creativity in Healthy Han Chinese Subjects

Although previous evidence has suggested that there is a genetic link between schizophrenia and creativity, the specific genetic variants that underlie the link are still largely unknown. To further explore the potential genetic link between schizophrenia and creativity, in a sample of 580 healthy Han Chinese subjects, this study aimed to (1) validate the role of Neuregulin 1 (NRG1) rs6994992 (one schizophrenia risk variant that has been previously linked to creativity in the European population) in the relationship between schizophrenia and creativity and (2) explore the associations between 10 other schizophrenia risk variants and creativity. For NRG1 rs6994992, the result validated its association with creativity measures. However, since NRG1 rs6994992 is not a schizophrenia risk variant in the Han Chinese population, the validated association suggested that ethnic difference may exist in the relationship between NRG1 rs6994992, schizophrenia and creativity. For other schizophrenia risk variants, the result only demonstrated a nominal association between ZNF536 rs2053079 and creativity measures which would not survive correction for multiple testing. No association between polygenic risk score for these 10 schizophrenia risk variants and creativity measures was observed. In conclusion, this study provides limited evidence for the associations between these schizophrenia risk variants and creativity in healthy Han Chinese subjects. Future studies are warranted to better understand the potential genetic link between schizophrenia and creativity.

A haplotype variant of the human chromogranin A gene (CHGA) promoter increases CHGA expression and the risk for cardiometabolic disorders

The acidic glycoprotein chromogranin A (CHGA) is co-stored/co-secreted with catecholamines and crucial for secretory vesicle biogenesis in neuronal/neuroendocrine cells. CHGA is dysregulated in several cardiovascular diseases, but the underlying mechanisms are not well established. Here, we sought to identify common polymorphisms in the CHGA promoter and to explore the mechanistic basis of their plausible contribution to regulating CHGA protein levels in circulation. Resequencing of the CHGA promoter in an Indian population (n = 769) yielded nine single-nucleotide polymorphisms (SNPs): G-1106A, A-1018T, T-1014C, T-988G, G-513A, G-462A, T-415C, C-89A, and C-57T. Linkage disequilibrium (LD) analysis indicated strong LD among SNPs at the -1014, -988, -462, and -89 bp positions and between the -1018 and -57 bp positions. Haplotype analysis predicted five major promoter haplotypes that displayed differential promoter activities in neuronal cells; specifically, haplotype 2 (containing variant T alleles at -1018 and -57 bp) exhibited the highest promoter activity. Systematic computational and experimental analyses revealed that transcription factor c-Rel has a role in activating the CHGA promoter haplotype 2 under basal and pathophysiological conditions (viz. inflammation and hypoxia). Consistent with the higher in vitro CHGA promoter activity of haplotype 2, individuals carrying this haplotype had higher plasma CHGA levels, plasma glucose levels, diastolic blood pressure, and body mass index. In conclusion, these results suggest a functional role of the CHGA promoter haplotype 2 (occurring in a large proportion of the world population) in enhancing CHGA expression in haplotype 2 carriers who may be at higher risk for cardiovascular/metabolic disorders.

Tumor necrosis factor-308 polymorphism with the risk and prognosis of non-Hodgkin lymphomas: a meta-analysis study

Background

Tumor necrosis factor-308 (TNF-308) was implied to be associated with the development of non-Hodgkin lymphoma (NHL). The aim of this meta-analysis study was to investigate the association of TNF-308A polymorphism with the susceptibility to, and prognosis of, NHL.

Methods

PubMed, Web of Science, Elsevier, HighWire, Scopus, and Google Scholar were searched up to May 2015. The association of TNF-308 polymorphism with the risk of NHL and prognosis was assessed by odds ratio and hazard ratio, respectively.

Results

Overall, TNF-308G>A polymorphism increased the risk of NHL, B-cell lymphomas (BCL), and T-cell lymphomas and decreased the risk of follicular lymphomas. In stratified analysis, increased risk of BCL and diffuse large B-cell lymphomas (DLBCL) were observed in Caucasians and population-based studies, whereas decreased risk of NHL, BCL, and DLBCL were detected in Asians and hospital-based studies. Furthermore, pooled results of 1,192 patients with NHL from five studies suggested that TNF-308A was correlated with shorter progression-free survival and overall survival in patients with NHL, BCL, and DLBCL.

Conclusion

Current evidence indicated that TNF-308A polymorphism was significantly associated with the risk and prognosis of NHL. Future studies should further confirm these associations in other NHL subtypes and ethnicities.

JAK-STAT and G-protein-coupled receptor signaling pathways are frequently altered in epitheliotropic intestinal T-cell lymphoma

Epitheliotropic intestinal T-cell lymphoma (EITL, also known as type II enteropathy-associated T-cell lymphoma) is an aggressive intestinal disease with poor prognosis and its molecular alterations have not been comprehensively characterized. We aimed to identify actionable easy-to-screen alterations that would allow better diagnostics and/or treatment of this deadly disease. By performing whole-exome sequencing of four EITL tumor-normal pairs, followed by amplicon deep sequencing of 42 tumor samples, frequent alterations of the JAK-STAT and G-protein-coupled receptor (GPCR) signaling pathways were discovered in a large portion of samples. Specifically, STAT5B was mutated in a remarkable 63% of cases, JAK3 in 35% and GNAI2 in 24%, with the majority occurring at known activating hotspots in key functional domains. Moreover, STAT5B locus carried copy-neutral loss of heterozygosity resulting in the duplication of the mutant copy, suggesting the importance of mutant STAT5B dosage for the development of EITL. Dysregulation of the JAK-STAT and GPCR pathways was also supported by gene expression profiling and further verified in patient tumor samples. In vitro overexpression of GNAI2 mutants led to the upregulation of pERK1/2, a member of MEK-ERK pathway. Notably, inhibitors of both JAK-STAT and MEK-ERK pathways effectively reduced viability of patient-derived primary EITL cells, indicating potential therapeutic strategies for this neoplasm with no effective treatment currently available.

Soluble levels of CD27 and CD30 are associated with risk of non-Hodgkin lymphoma in three Chinese prospective cohorts

Prospective studies conducted in Western populations have suggested that alterations in soluble CD27 (sCD27) and soluble CD30 (sCD30), two markers indicative of B-cell activation, are associated with risk of non-Hodgkin lymphoma (NHL). Given that the characteristics of NHL in East Asia differ from the West and mechanistic commonalities between these populations with respect to the role of intermediate endpoint biomarkers in lymphomagenesis have not been explored, we conducted a pooled nested case-control study from three prospective studies of Chinese men and women including 218 NHL cases and 218 individually matched controls. Compared with the lowest quartile, ORs (95% CIs) for the second, third and fourth quartiles of sCD27 were 1.60 (0.83-3.09), 1.94 (0.98-3.83) and 4.45 (2.25-8.81), respectively (p(trend) = 0.000005). The corresponding ORs for sCD30 were 1.74 (0.85-3.58), 1.86 (0.94-3.67) and 5.15 (2.62-10.12; p(trend) = 0.0000002). These associations remained statistically significant in individuals diagnosed with NHL 10 or more years after blood draw. Notably, the magnitude of the associations with NHL risk was very similar to those in Western populations in previous studies. These findings of the similar association between sCD27 or sCD30 and NHL risk across different populations support an important underlying mechanism of B-cell activation in lymphomagenesis.

Inter-ethnic differences in genetic variants within the transmembrane protease, serine 6 (TMPRSS6) gene associated with iron status indicators: a systematic review with meta-analyses

Transmembrane protease, serine 6 (TMPRSS6), is likely to be involved in iron metabolism through its pleiotropic effect on hepcidin concentrations. Recently, genome-wide association studies have identified common variants in the TMPRSS6 gene to be linked to anaemia and low iron status. To get a more precise evaluation of identified TMPRSS6 single nucleotide polymorphism associations with iron status in cohorts of differing continental ancestry, we conducted a systematic review with meta-analyses. We searched the literature using HuGE Navigator, Pubmed and Scopus databases for primarily genome-wide association studies using TMPRSS6 as a free term. Fixed-effects meta-analysis was used to obtain summary estimates of associations. Eleven studies comprised Caucasian populations, four included an Asian population and one study included an African-American population. Differences in minor allele frequencies of 8 TMPRSS6 SNPs (rs855791, rs4820268, rs2111833, rs1421312, rs228921, rs228918, rs228919 and rs575620) across ethnic groups were observed, with the MAF of rs855791 significantly higher in Asian populations than in Caucasians (0.55 vs 0.42, P < 0.0001). In the meta-analysis, the A allele of rs855791 was associated with lower Hb and ferritin concentrations in all populations. This allele was also associated with increased serum transferrin receptor and transferrin concentrations. We observed similar associations for the G allele in rs4820268. Clear disparities in associations were found for the African-American population, although not statistically significant. Associations between TMPRSS6 SNPs and anaemia are consistent across Caucasian and Asian populations. This study highlights the need to conduct studies in African populations where iron deficiency is of utmost public health significance.

IL10 and TNF variants and risk of non-Hodgkin lymphoma among three Asian populations

Genetic variation in immune-related genes, such as IL10 and TNF, have been associated with the development of non-Hodgkin lymphoma (NHL) in Caucasian populations. To test the hypothesis that IL10 and TNF polymorphisms may be associated with NHL risk in Asian populations, we genotyped 20 single nucleotide polymorphisms (SNPs) within the IL10 and TNF/LTA loci in three independent case-control studies (2635 cases and 4234 controls). IL10 rs1800871, rs1800872, and rs1800896 were genotyped in all three studies, while 5 of the remaining SNPs were genotyped in two studies, and 12 in a single study. IL10 rs1800896 was associated with B cell lymphoma [per-allele odds ratio (OR) = 1.25, 95 % confidence interval (CI) 1.08-1.45; p trend = 0.003], specifically diffuse large B cell lymphoma (DLBCL) (per-allele OR = 1.29, 95 % CI 1.08-1.53; p trend = 0.004), as well as T cell lymphoma (per-allele OR = 1.44, 95 % CI 1.13-1.82; p trend = 0.003). TNF rs1800629, which was genotyped in only two of our studies, was also associated with B cell lymphoma (per-allele OR = 0.77, 95 % CI 0.64-0.91; p trend = 0.003), specifically DLBCL (per-allele OR = 0.69, 95 % CI 0.55-0.86; p trend = 0.001). Our findings suggest that genetic variation in IL10 and TNF may also play a role in lymphomagenesis in Asian populations.

Type II EATL (epitheliotropic intestinal T-cell lymphoma): a neoplasm of intra-epithelial T-cells with predominant CD8αα phenotype

In this multicentre study, we examined 60 cases of Type II enteropathy-associated T-cell lymphoma (EATL) from the Asia-Pacific region by histological review, immunohistochemistry and molecular techniques. Patients were mostly adult males (median age: 58 years, male:female 2.6:1), presenting with abdominal pain (60%), intestinal perforation (40%) and weight loss (28%). None had a history of coeliac disease and the median survival was only 7 months. Histologically, these tumours could be divided into (i) central tumour zone comprising a monotonous population of neoplastic lymphocytes, (ii) peripheral zone featuring stunted villi and morphologically atypical lymphocytes showing epitheliotropism, and (iii) distant mucosa with normal villous architecture and cytologically normal intra-epithelial lymphocytes (IELs). Characterized by extensive nuclear expression of Megakaryocyte-associated tyrosine kinase (MATK) (87%) and usually a CD8(+)CD56(+) (88%) cytotoxic phenotype, there was frequent aberrant expression of CD20 (24%). T-cell receptor (TCR) expression was silent or not evaluable in 40% but of the remainder, there was predominant expression of TCRαβ over TCRγδ (1.6:1). In keeping with the normal ratio of IEL subsets, CD8(+) cases showed predominant CD8αα homodimer expression (77%), regardless of TCR lineage. These tumours constitute a distinct entity from classical EATL, and the pathology may reflect tumour progression from IEL precursors, remnants of which are often seen in the distant mucosa.

An association study between polymorphisms of the fractalkine receptor gene, CX3CR1, and cerebral infarction in the Han Chinese population

OBJECTIVE

The aim of this study was to investigate the association between polymorphisms of CX3CR1 and the occurrence, neurological rehabilitation and 3-month outcome of cerebral infarction in the Han Chinese population.

METHODS

We investigated the V249I and T280M mutations of CX3CR1 in 308 consecutive Han Chinese patients that were diagnosed with cerebral infarction and 294 age- and gender-matched healthy control subjects. The patients were classified with Oxfordshire Community Stroke Project (OCSP) classification, evaluated with a National Institute of Health Stroke Scale (NIHSS) score for an acute stage of stroke and assessed with a Barthel Index (BI) score 3months after stroke. Polymorphic genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP).

RESULTS

We found no statistically significant difference in the V249I and T280M polymorphisms between the patients and controls. The I249 and M280 allele frequencies of CX3CR1 were not significantly different between the patients and controls. No differences were observed in the genotype distributions and allele frequencies of CX3CR1 among the OCSP stroke subtypes. No statistically significant association was found between the polymorphisms of CX3CR1 and NIHSS scores of cerebral infarction at the acute stage or with the 3-month BI scores obtained after cerebral infarction.

CONCLUSION

Our results demonstrated that the polymorphisms of CX3CR1 might not associate with the occurrence, neurological rehabilitation and 3-month outcome of cerebral infarction in the Han Chinese population.

Worldwide genetic structure in 37 genes important in telomere biology

Telomeres form the ends of eukaryotic chromosomes and are vital in maintaining genetic integrity. Telomere dysfunction is associated with cancer and several chronic diseases. Patterns of genetic variation across individuals can provide keys to further understanding the evolutionary history of genes. We investigated patterns of differentiation and population structure of 37 telomere maintenance genes among 53 worldwide populations. Data from 898 unrelated individuals were obtained from the genome-wide scan of the Human Genome Diversity Panel (HGDP) and from 270 unrelated individuals from the International HapMap Project at 716 single-nucleotide polymorphism (SNP) loci. We additionally compared this gene set to HGDP data at 1396 SNPs in 174 innate immunity genes. The majority of the telomere biology genes had low to moderate haplotype diversity (45-85%), high ancestral allele frequencies (>60%) and low differentiation (FST<0.10). Heterozygosity and differentiation were significantly lower in telomere biology genes compared with the innate immunity genes. There was evidence of evolutionary selection in ACD, TERF2IP, NOLA2, POT1 and TNKS in this data set, which was consistent in HapMap 3. TERT had higher than expected levels of haplotype diversity, likely attributable to a lack of linkage disequilibrium, and a potential cancer-associated SNP in this gene, rs2736100, varied substantially in genotype frequency across major continental regions. It is possible that the genes under selection could influence telomere biology diseases. As a group, there appears to be less diversity and differentiation in telomere biology genes than in genes with different functions, possibly due to their critical role in telomere maintenance and chromosomal stability.

The APOA1/C3/A4/A5 cluster and markers of allostatic load in the Boston Puerto Rican Health Study

BACKGROUND AND AIMS

The APOA1/C3/A4/A5 cluster encodes key regulators of plasma lipids. Interactions between dietary factors and single nucleotide polymorphisms (SNPs) in the cluster have been reported. Allostatic load, or physiological dysregulation in response to stress, has been implicated in shaping health disparities in ethnic groups. We aimed to determine the association between polymorphisms in the APOA1/C3/A4/A5 cluster with allostatic load parameters, alone, and in interaction with dietary fat intake in Puerto Ricans adults.

METHODS AND RESULTS

Data on demographic and anthropometric measures, lifestyle behaviors, and medication use, as well as blood and urine samples for biomarker analysis, were obtained from participants of the Boston Puerto Rican Health Study (n=821, age 45-75 y). The 12 polymorphisms analyzed were not associated with allostatic load parameters. Significant interactions were observed between dietary fat intake and APOA1-75 in association with waist circumference (WC), (P=0.005), APOC3-640 with diastolic blood pressure (DBP), (P=0.003), and APOA4 N147S and APOA5 S19W with systolic blood pressure (SBP), (P=0.001 and P=0.002, respectively). Puerto Ricans homozygous for the common allele of APOA1-75, APOA4 N147S and APOA5 S19W had lower WC and SBP when consuming <31% of total fat from energy, than participants with the minor allele. Participants heterozygous for APOC3-640 had lower DBP at total fat intake ≥31% from energy.

CONCLUSION

SNPs in APOA1/C3/A4/A5, as modulated by dietary fat intake, appear to influence allostatic load parameters in Puerto Ricans.

Variants of the CD36 gene and metabolic syndrome in Boston Puerto Rican adults

OBJECTIVE

Puerto Ricans experience a high prevalence of several chronic conditions, including metabolic syndrome. Genetic variants of the CD36 gene have been associated with metabolic syndrome. We aimed to determine the association between 6 single nucleotide polymorphisms (SNPs) for CD36 and metabolic syndrome and its components in Puerto Ricans (45-75 year) living in the Greater Boston area.

METHODS

Associations between each SNP, metabolic syndrome and its components were examined using multivariate logistic regression models. Haplotype trend regression analysis was used to determine associations between haplotypes and metabolic syndrome.

RESULTS

For two SNPs of CD36 (rs1049673 and rs3211931), homozygous subjects of the minor allele (G and T, respectively) were associated with a higher likelihood of metabolic syndrome (odds ratio (OR) (95% confidence interval (CI)): 1.89 (1.0, 3.5) and 1.77 (1.0, 3.1), respectively) relative to carriers of the major allele. Although CD36 haplotypes were not significantly associated with metabolic syndrome overall (global significance, P=0.23), one haplotype (G-C-C vs. C-C-C (reference haplotype)) was marginally associated (P=0.049).

CONCLUSION

SNPs of CD36 were associated with metabolic syndrome in Puerto Ricans. Prospective studies should further explore the role of CD36 variants in the development of this condition.

Apolipoprotein A5 polymorphisms interact with total dietary fat intake in association with markers of metabolic syndrome in Puerto Rican older adults

APOA5 -1131T > C and S19W single nucleotide polymorphisms (SNP) have been consistently associated with plasma lipid concentration and metabolic syndrome (MetS), alone and in modulation by dietary factors. Puerto Ricans have a high prevalence of metabolic conditions and high minor allele frequency for these SNP, suggesting a possible role in disease for this population. We aimed to determine the association of APOA5 -1131T > C and S19W with plasma lipids and markers of MetS, alone and in interaction with total fat intake, as a percent of total energy intake, in Puerto Ricans. Anthropometric and demographic data, FFQ, and blood samples were collected at baseline from participants in the Boston Puerto Rican Health Study (n = 802, 45-75 y). APOA5 S19W was associated with plasma HDL cholesterol (HDL-C) (P = 0.044); minor allele carriers had lower HDL-C [1.12 +/- 0.03 (mean +/- SE)] than those with the common variant (1.18 +/- 0.01 mmol/L), even after adjustment for plasma triglycerides (TG) (P = 0.012). Neither polymorphism was associated with TG or other lipids. Interaction of the -1131T > C SNP with total fat energy intake was observed for plasma TG (P = 0.032) and total cholesterol (P = 0.034). APOA5 S19W interacted with total fat intake in association with systolic (P = 0.002) and diastolic (P = 0.007) blood pressure. Neither SNP was associated with MetS in the overall analysis or after stratifying by total energy intake as fat. In conclusion, Puerto Ricans present a distinctive lipid profile in association with APOA5 polymorphisms. Dietary fat intake seems to modulate these associations. The results contribute to the understanding of health disparities in this population.

Disparities in allele frequencies and population differentiation for 101 disease-associated single nucleotide polymorphisms between Puerto Ricans and non-Hispanic whites

Background

Variations in gene allele frequencies can contribute to differences in the prevalence of some common complex diseases among populations. Natural selection modulates the balance in allele frequencies across populations. Population differentiation (F_ST) can evidence environmental selection pressures. Such genetic information is limited in Puerto Ricans, the second largest Hispanic ethnic group in the US, and a group with high prevalence of chronic disease. We determined allele frequencies and population differentiation for 101 single nucleotide polymorphisms (SNPs) in 30 genes involved in major metabolic and disease-relevant pathways in Puerto Ricans (n = 969, ages 45–75 years) and compared them to similarly aged non-Hispanic whites (NHW) (n = 597).

Results

Minor allele frequency (MAF) distributions for 45.5% of the SNPs assessed in Puerto Ricans were significantly different from those of NHW. Puerto Ricans carried risk alleles in higher frequency and protective alleles in lower frequency than NHW. Patterns of population differentiation showed that Puerto Ricans had SNPs with exceptional F_ST values in intronic, non-synonymous and promoter regions. NHW had exceptional F_ST values in intronic and promoter region SNPs only.

Conclusion

These observations may serve to explain and broaden studies on the impact of gene polymorphisms on chronic diseases affecting Puerto Ricans.

Association of MIF promoter polymorphisms with psoriasis in a Han population in northeastern China

BACKGROUND

Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that plays an important part in the pathogenesis of autoimmune diseases. A high level of MIF has been detected in plaques of psoriasis and the sera of patients with psoriasis. Polymorphisms associated with autoimmune and inflammatory diseases exist in the promoter region of MIF and alter its expression.

OBJECTIVE

The aim of this study was to evaluate the potential relationship between functional polymorphisms of MIF and psoriasis in a Han population in northeastern China.

METHODS

Two-hundred-and-forty psoriasis patients and a control group of 269 healthy volunteers were included in this study. We genotyped MIF-173G/C using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). MIF-794CATT(5-8) microsatellite polymorphism was genotyped by polyacrylamide gel electrophoresis (PAGE).

RESULTS

No significant difference in the distributions of alleles, genotypes and haplotypes was observed between patients and controls. When patients were divided into subtypes according to sex, family history and age of onset, distribution of the MIF-173C allele between male and female patients was significantly different (P=0.04). MIF-173C allelic distribution between late onset psoriasis patients and controls was also different (P=0.02), as well as late onset patients and early onset subjects (P=0.04).

CONCLUSIONS

These results suggested a preliminary association between the MIF-173C allele and male psoriasis and late onset psoriasis in the studied population. In addition, the distributions of the two polymorphisms in Asian populations were quite different from the other continental populations.