Impact of cognition-related single nucleotide polymorphisms on brain imaging phenotype in Parkinson’s disease

Multiple single nucleotide polymorphisms may contribute to cognitive decline in Parkinson’s disease. However, the mechanism by which these single nucleotide polymorphisms modify brain imaging phenotype remains unclear. The aim of this study was to investigate the potential effects of multiple single nucleotide polymorphisms on brain imaging phenotype in Parkinson’s disease. Forty-eight Parkinson’s disease patients and 39 matched healthy controls underwent genotyping and 7 T magnetic resonance imaging. A cognitive-weighted polygenic risk score model was designed, in which the effect sizes were determined individually for 36 single nucleotide polymorphisms. The correlations between polygenic risk score, neuroimaging features, and clinical data were analyzed. Furthermore, individual single nucleotide polymorphism analysis was performed to explore the main effects of genotypes and their interactive effects with Parkinson’s disease diagnosis. We found that, in Parkinson’s disease, the polygenic risk score was correlated with the neural activity of the hippocampus, parahippocampus, and fusiform gyrus, and with hippocampal-prefrontal and fusiform-temporal connectivity, as well as with gray matter alterations in the orbitofrontal cortex. In addition, we found that single nucleotide polymorphisms in α-synuclein(SNCA) were associated with white matter microstructural changes in the superior corona radiata, corpus callosum, and external capsule. A single nucleotide polymorphism in catechol-O-methyltransferase was associated with the neural activities of the lingual, fusiform, and occipital gyri, which are involved in visual cognitive dysfunction. Furthermore, DRD3 was associated with frontal and temporal lobe function and structure. In conclusion, imaging genetics is useful for providing a better understanding of the genetic pathways involved in the pathophysiologic processes underlying Parkinson’s disease. This study provides evidence of an association between genetic factors, cognitive functions, and multi-modality neuroimaging biomarkers in Parkinson’s disease.

Single nucleotide polymorphism C677T in the methylenetetrahydrofolate reductase gene might be a genetic risk factor for infertility for Chinese men with azoospermia or severe oligozoospermia

Aim： To analyze the distribution of the single nucleotide polymorphism （SNP） C677T in the methylenetetrahydrofolate reductase （MTHFR） gene in 355 infertile Chinese patients with idiopathic azoospermia or severe oligozoospermia and 252 fertile Chinese men as controls to explore the possible association of the SNP and male infertility. Methods： Using the polymerase chain reaction （PCR）-restriction fragment length polymorphism technique, the allele and genotype distribution of SNP C677T in the MTHFR gene were investigated in both patients and controls. Results： The frequencies of allele T （40.9% vs 30.4%, P = 0.002, odds ration [OR] = 1.58, 95% confidence interval [CI]： 1.24-2.02） and mutant homozygote （TT） （18.3% vs. 11.5%, P = 0.023, OR = 1.72, 95% CI： 1.07-2.76） as well as carrier with allele （TT ＋ CT） （63.4% vs. 49.2%, P = 0.0005, OR = 1.79, 95% CI： 1.29-2.48） in infertile patients were significantly higher than those in controls. After patient stratification, the significant differences in distribution of the SNP between each patient subgroup and control group still remained. Conclusion： Our findings indicate that there is an association of SNP C677T in the MTHFR gene with male infertility, suggesting that this polymorphism might be a genetic risk factor for male infertility in Chinese men.

Identification of a Regulatory Single Nucleotide Polymorphism in the Adiponectin (APM1) Gene Associated with Type 2 Diabetes in Han Nationality

Objective To identify the genetic defects of the the adiponectin （APM1） gene that contribute to the development of type 2 diabetes （T2DM） and determine the functional single nucleotide polymorphisms （SNPs） in the APMI gene associated with T2DM in Han nationality. Methods The APMI gene 5＇-UTR was screened by direct sequencing to identify common polymorphisms. Identified SNPs were genotyped in 585 nondiabetic controls, 278 subjects with impaired glucose intolerance （IGT） and 212 patients with T2DM. The functions of SNPs in the regulatory region were assessed by reporter gene assay. Possible association between SNPs and plasma APMI levels or metabolic parameters was statistically asses,sed. Results Three SNPs were identified in the APMI gene 5＇-UTR. A case-control study revealed that SNP -11377 G/C had significant differences in allele frequencies between T2DM patients and nondiabetic controls （G 0.314/C 0.686 vs. G 0.265/C 0.735, P=0.03）. Haplotype analysis of three SNPs in the APM1 gene showed that no significant association of haplotypes with T2DM. IGT was detected in the present study. Reporter gene assay showed that SNP did not influence the transcription efficiency in the 3T3-LI cell line. Conclusion SNP - 11377 G/C in the proximal promoter region of the APM 1 gene contributes to the development of T2DM in Han nationality but may not be a functional SNP in the APM1 gene.

Single Nucleotide Polymorphisms (SNPs) Discovery and Linkage Disequilib-rium (LD) in Forest Trees

With completion of the Populus genome sequencing project and the availability of many expressed sequence tags （ESTs） databases in forest trees, attention is now rapidly shifting towards the study of individual genetic variation in natural populations. The most abundant form of genetic variation in many eukaryotic species is represented by single nucleotide polymorphisms （SNPs）, which can account for heritable inter-individual differences in complex phenotypes. Unlike humans, the linkage disequilibrium （LD） rapidly decays within candidate genes in forest trees. Thus, SNPs-based candidate gene association studies are considered to be a most effective approach to dissect the complex quantitative traits in forest trees. The present study demonstrates that LD mapping can be used to identify alleles associated with quantitative traits and suggests that this new approach could be particularly useful for performing breeding programs in forest trees. In this review, we will describe the fundamentals, patterns of SNPs distribution and frequency, summarize recent advances in SNPs discovery and LD and comment on the application of LD in the dissection of complex quantitative traits in forest tress. We also put forward the outlook for future SNPs-based association analysis of quantitative traits in forest trees.

Expression analysis,single nucleotide polymorphisms within SIRT4 and SIRT7 genes and their association with body size and meat quality traits in Qinchuan cattle

Silent information regulator 2 （Sir2） proteins, or sirtuins, are nicotine adenine dinucleotide （NAD）-dependent deacetylases that connect metabolism with longevity in lower organisms. In mammals, there are seven Sir2 homologs, namely, silent information regulators （SIRT1-7）. SIRT4 and SIRT7 genes play a crucial role in regulating lipid metabolism, cellular growth and metabolism. This suggests that they are potential candidate genes for affecting body size and meat quality traits in animals. Hence, this study aimed to detect genetic variations of both SIRT4 and SIRT7 bovine genes in Qinchuan cattle, and to evaluate the effect of these variations on economically important body size and meat quality traits. Expression analysis using quantitative real-time PCR （qPCR） indicated that SIRT4 and SIRT7 were broadly expressed in all thirteen studied tissues. The expression of SIRT4 was higher in liver, muscle, and in subcutaneous fat tissue. In the case of SIRT7, the expression was higher in lung, abomasum, and subcutaneous fat. Using DNAsequencing, a total of three single nucleotide polymorphisms （SNPs） were identified within SIRT4 and SIRT7 genes in 468 Qinchuan cattle. These included one novel SNP within 3＇ untranslated regions （UTR） of SIRT4 （SNP1： g. 13915A〉G） and two novel synonymous substitutions in SIRT7 （SNP2： g.3587C〉T and SNP3： g.3793T〉C）. Statistical analyses indicated that all three SNPs could significantly influence some body size and meat quality traits in Qinchuan cattle. These novel findings will provide a background for application of bovine SIRT4 and SIRT7 genes in the selection program of Chinese cattle.

Association of three single nucleotide polymorphisms of ESR1 with breast cancer susceptibility:a meta-analysis

Expression of estrogen receptors is correlated with breast cancer risk,but inconsistent results have been reported.To clarify potential estrogen receptor（ESR）-related breast cancer risk,we analyzed genetic variants of ESR1 in association with breast cancer susceptibility.We performed a meta-analysis to investigate the association between rs2234693,rs1801132,and rs2046210（single nucleotide polymorphisms of ESR1）,and breast cancer risk.Our analysis included 44 case-control studies.For rs2234693,the CC genotype had a higher risk of breast cancer compared to the TT or CT genotype.For rs2046210,the AA,GA,or GA ＋ GG genotype had a much higher risk compared to the GG genotype.No significant association was found for the rs 1801132 polymorphism with breast cancer risk.This meta-analysis demonstrates association between the rs2234693 and rs2046210 polymorphisms of ESR1 and breast cancer risk.The correlation strength between rs2234693 and breast cancer susceptibility differs in subgroup assessment by ethnicity.

Tagging single nucleotide polymorphisms in the PPAR-γ and RXR-α gene and type 2 diabetes risk:a case-control study of a Chinese Han population

Peroxisome proliferator-activated receptor （PPAR-γ）,which is mainly involved in adipocyte differentiation, has been suggested to play an important role in the pathogenesis of insulin resistance and atherosclerosis. We investigated the frequencies of two common tagging polymorphisms of the PPAR-γ gene and two of PPAR-α with minor allele frequency （MAF）≥ 0.05 in the Chinese Han population and analyzed the correlation between the different genotypes and the risk of type 2 diabetes mellitus （T2DM）. TaqMan assay was performed to test the genotypes in T2DM patients （n = 1,105） and normal controls （n = 1,107）. Serum adiponectin concentration was measured by ELISA kit. The variant genotypes rs17817276GG, rs3856806CT and rs3856806CT/TT of PPAR-γ were associated with T2DM, P = 0.023,0.037 and 0.018, respectively. Furthermore, the prevalence of haplotype GT in PPAR-γ was less frequent in the case subjects （0.3%） than in the controls （1.9%） [P 0.001,OR（95%CI）=0.13 （0.06-0.31）]. Patients with genotype TT of rs3856806 had a higher serum level of adiponectin than those with the genotype CC and CT （P = 0.031 and 0.038, respectively）. There was no statistically significant difference between patients and controls in genotype distribution of rs6537944 and rs1045570 of the RXR-α gene. The present study suggests that the variant genotypes in the PPAR-γ gene could decrease the risk for the development of T2DM in the Chinese Han population.

Association of single nucleotide polymorphisms of brain-derived neurotrophic factor gene and multidrug resistance 1 gene to refractory epilepsy in Chinese Han children

BACKGROUND： There are two hypotheses for the underlying cause of refractory epilepsy： ＂target＂ and ＂transport＂. Studies have shown that brain-derived neurotrophic factor （BDNF） is over-expressed in refractory epilepsy. Multidrug resistance 1 （MDR1） gene encodes for P-glycoprotein, the primary ATP-binding cassette transporter in the human body. Some single nucleotide polymorphisms of the MDR1 gene have been associated with refractory epilepsy. OBJECTIVE： To investigate the association between BDNF gene C270T polymorphism and MDR1 T-129C polymorphism with refractory epilepsy in Chinese Han children through the use of polymerase chain reaction （PCR）-restriction fragment length polymorphism analysis. DESIGN, TIME AND SETTING： A case-control, genetic association study was performed at the Central Laboratory, Third Xiangya Hospital of Central South University from June 2005 to November 2007. PARTICIPANTS： A total of 84 cases of unrelated children with epilepsy, including 41 cases of refractory epilepsy and 43 cases of drug-responsive epilepsy, were enrolled. An additional 30 healthy, Chinese Han children, whose ages and gender matched the refractory epilepsy patients, were selected as normal controls. METHODS： Venous blood was collected and genomic DNA was extracted from the blood specimens. C270T polymorphism in BDNF gene and T-129C polymorphism in MDR1 gene were genotyped using PCR-restriction fragment length polymorphism analysis. Association analysis using the Ftest and Chi-square test was statistically performed between C270T polymorphism in BDNF gene and T-129C polymorphism in MDR1 gene and refractory epilepsy. MAIN OUTCOME MEASURES： The distribution of genotypes and allele frequencies of C270T polymorphism in BDNF gene and T-129C polymorphism in MDR1 gene. RESULTS： The distribution of CC, CT, and TT genotypes, as well as C and T allele frequencies, in the BDNF gene was not significantly different between the refractory epilepsy group, drug-responsive epilepsy group, or the normal control group （P 〉 0.05）. The distribution of TT genotype and T allele frequencies of the MDR1 gene was significantly different in the refractory epilepsy group compared with the drug-responsive epilepsy and normal control groups （P 〈 0.05）. Comparison of haplotype combinations demonstrated that there were no significant differences in combinations of TT＋CC, -FI-＋CT, TC＋CC, and TC＋CT among the three groups （P 〉 0.05）. CONCLUSION： C270T polymorphism of the BDNF gene was not associated with refractory epilepsy in Chinese Han children, but T-129C polymorphism in the MDR1 gene was associated with refractory epilepsy in Chinese Han children. The TT genotype and T allele frequencies could serve as susceptibility loci for refractory epilepsy. Interactions between C270T in BDNF gene and T-129C in MDR1 gene were not observed in refractory epilepsy in Chinese Han children.

Single Nucleotide Polymorphism of CYP3A4 Intron 2 and Its Influence on CYP3A4 mRNA Expression and Liver Enzymatic Activity in Human Liver

Summary： In adult liver, CYP3A4 plays an important role in the metabolism of a wide range of en- dogenous and exogenous compounds. To investigate whether there is a single nucleotide polymorphism （SNP） of CYP3A4 intron 2 in the liver and its effects on the mRNA expression and enzymatic activity of CYP3A4, genomic DNA was extracted from 96 liver tissue samples obtained from patients who had undergone liver surgery. An SNP of CYP3A4 intron 2 was identified by polymerase chain reaction （PCR）-single-strand confirmation polymorphism and DNA sequencing. The mRNA expression of CYP3A4 was determined by the fluorescence quantitative PCR technique. The enzymatic activity of CYP3A4 was measured using erythromycin and testosterone as probe substrates. Twelve patients were found to have the SNP/T4127G CYP3A4 within intron 2. The mRNA levels of CYP3A4 in wild-type and SNP/T4127G samples were 2.62±1.09 and 2.79±1.63, respectively （P〉0.05）. Erythromycin N-demethylase activity in wild-type and SNP/T4127G samples were 121.2±32.8 and 124.7±61.6 nmol·mg^-1min^-1, respectively （P〉0.05）. The activity of testosterone 613-hydroxylase was significantly different between wild-type （648±173 pmol·mg^-1·min^-1） and SNP/T4127G samples （540-4-196 pmol.mg-l-minl; P〈0.05）. In conclusion, the SNP/T4127G of CYP3A4 intron 2 exists in the liver. This SNP does not affect the mRNA expression of CYP3A4 but significantly decreases the hepatic micro- somal testosterone 613-hydroxylase activity of CYP3A4. Furthermore, this study indicates that the ap- propriate selection of probe substrates is very important in studying the relationship between the geno- type and phenotype of CYP3A4.

Isolation,expression and single nucleotide polymorphisms(SNPs) analysis of LACCASE gene(LkLAC8) from Japanese larch(Larix kaempferi)

Nucleotide diversity (pi) and linkage disequilibrium (LD) analysis based on SNP marker could provide a sound basis for choosing an association analysis method. Japanese larch (Larix kaempferi) is an important timber coniferous tree species for pulping and papermaking, but its high lignin content has significantly restricted it application potential. In this study, the LACCASE gene, that plays an important regulatory role for lignin biosynthesis, was selected as research target. The full-length cDNA and genomic sequences of the encoding LkLAC8 gene were isolated from the LACCASE expressed sequence tags of the Japanese larch transcriptome database using the rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). The cDNA was determined to be 1940 bp, with an open reading frame (ORF, 1734 bp) that encoded a protein of 577 AA. This protein contains four highly specific Cu2+ binding sites and 11 glycosylation sites, thus belonging to the LACCASE family. The deduced protein sequence shared an 89% identity with the PtaLAC from Pinus taeda. A real-time PCR analysis showed that the LkLAC8 transcript was expressed predominantly in mature xylem, with moderate levels in the immature xylem, cambium and mature leaves, the lowest in the roots. Lastly, the genomic sequences of LkLAC8 in 40 individuals from six naturally distributed populations of Japanese larch were amplified, and a total of 201 SNPs (103 and 98 mutation types of transition and transversion, respectively) were detected; the frequency of the SNPs was 1/19 bp. Nucleotide diversity among the six populations ranged from 0.0034 to 0.0053, which suggested that there were no significant differences among the populations. The LD analysis showed that the LD level decayed rapidly within the increasing length of the LkLAC8 gene. These results implied that LD mapping and association analysis based on candidate gene may be feasible for the marker-assisted breeding of new germplasms with low lignin in Japanese larch.

Relationship between Single Nucleotide Polymorphisms in -174G/C and -634C/G Promoter Region of Interleukin-6 and Prostate Cancer

The association between the single nucleotide polymorphisms （SNPs） in -174G/C and -634C/G of interleukin-6 （IL-6） promoter region and prostate cancer was examined in the population of Han people in Hubei region. TaqMan PCR was employed for the gene-typing of -174G/C and -634C/G in promoter region of IL-6 gene to compare the prostate cancer patients and normal controls in terms of genotype frequency, allele frequency and risk of prostate cancer. Enzyme-linked immu- nosorbent assay （ELISA） was used for the detection of IL-6 concentration in peripheral blood of the patients with prostate cancer and the relationship between the IL-6 level and the genotype was studied. Our results showed that in all the subjects, the genotype of genetic locus -174G/C was found to be GG and no CG and CC were observed. There was a significant difference in gene frequency of GG, CG and CC of -634C/G and allele frequency of G and C between prostate cancer patients and normal controls （P〈0.05） and the gene frequency of GG＋CG increased with the clinical stages and pathological grades of prostate cancer. The IL-6 level in GG＋CG group was significantly higher than that in CC group. It was concluded that no SNP in -174G/C IL-6 promoter region was found in the population of Han people in Hubei region. The SNP in -634C/G was, to some extent, associated with the development and progression of prostate cancer. The population with GG＋CG genetype has higher risk for prostate cancer.

A Novel Real-time Fluorescence Mutant-allele-specific Amplification Method for Rapid Single Nucleotide Polymorphism Analysis

Current methods for single nucleotide polymorphism （SNP） analysis are timeconsuming and complicated. We aimed at development of one-step real-time fluorescence mutant-allele-specific amplification （MASA） method for rapid SNP analysis. The method is a marriage of two technologies： MASA primers for target DNA and a double-stranded DNA-selective fluorescent dye, SYBR Green I. Genotypes are separated according to the different threshold cycles of the wild-type and mutant primers. K-ras oncogene was used as a target to validate the feasibility of the method. The experimental results showed that the different genotypes can be clearly discriminated by the assay. The real-time fluorescence MASA method will have an enormous potential for fast and reliable SNP analysis due to its simplicity and low cost.

A single nucleotide polymorphism in the IL1RL1 gene is associated with Behcet's disease in a Chinese Han population

AIM:To explore the association of single nucleotide polymorphisms(SNPs)in the IL33/IL1RL1 gene region with the susceptibility to Behcet’s disease(BD)in a Chinese Han population.METHODS:A total of eight SNPs in the candidate gene region(rs11792633,rs7025417,rs10975519 and rs1048274 in IL33;rs2310220,rs12712142,rs13424006 and rs3821204 in IL1RL1)were genotyped in783 BD patients and 701 healthy controls by the Sequenom Mass Array i PLEX platform.RESULTS:A statistically significant association was observed between IL1RL1 rs12712142 and BD patients.The frequency of IL1RL1 rs12712142 variant allele A was significantly lower in BD patients than that in controls(OR=0.8,95%CI:0.69-0.94,Pc=0.039);the genotype distribution(Pc=0.043)and additive and dominant genetic model analyses(OR=0.8,95%CI:0.69-0.94,Pc=0.040 and OR=0.72,95%CI:0.58-0.88,Pc=0.011)also indicated a strong association between rs12712142 and BD patients.CONCLUSION:This is the first study to reveal the association between IL1RL1 rs12712142 variant allele A and the decreased risk of BD in the Chinese Han population,indicating a protective role of IL1RL1 in the pathogenesis of BD.

Single Nucleotide Polymorphisms in a Male Infertility-Related Gene CatSper

Objective To identify single nucleotide polymorphisms (SNPs) of human CatSper gene, themouse homologous gene product, which plays a crucial role in mouse male sterility.Methods We demonstrated a systematic screening of SNPs in coding regions and flankingintronic regions of human CatSper gene in a sample subset from a total 210 male individuals byDNA sequencing. Then we used PCR single-strand conformation polymorphism (SSCP) analy-sis to determine the allele frequencies of the possible SNPs among the whole 210 Chinese Hanmale individuals.Results Three SNPs, including two novels, were identified and their allele frequencies weredetermined in the 210 Chinese Han male individuals. These SNPs were assembled into largeSNP database that promises to enable the dissection of the genetic basis of disease.

Development of organelle single nucleotide polymorphism (SNP) markers and their application for the identification of cytoplasmic inheritance patterns in Pyropia yezoensis (Bangiales,Rhodophyta)

The genus Pyropia contains several important cultivated species.Genetic research in nori species has mainly focused on the cell nucleus,with few studies on organelles(chloroplast and mitochondria).Due to the high copy numbers of organelles in cells,which influence the development and traits of algae,it is necessary to study their genetic mechanism.In this study,the marine red alga Pyropia yezoensis,an important economic macroalga,was selected as the study object.To investigate organelle(chloroplast and mitochondria)inheritance in P.yezoensis,the wild type RZ(maternal strain)was crossed with the red mutant HT(paternal strain)and 30 color-sectors from 11 F1 gametophytic blades were examined.The complete chloroplast and mitochondrial genomes of the red mutant(HT)were assembled for the first time.One reliable and stable single nucleotide polymorphism(SNP)loci filtrated by bioinformatics analysis was used as a molecular marker for chloroplast and mitochondrial DNA,respectively,in subsequent experiments.PCR amplification and sequence analysis showed that the haplotypes of color-sectors detected were consistent with those of the maternal parent,confirming that both chloroplast and mitochondrial genomes were inherited maternally in P.yezoensis.The inheritance pattern of organelles in P.yezoensis can be used to guide the hybridization and breeding of nori.Additionally,the organelle SNP markers developed in this study can be applied in subsequent genetic research.

Assessment of single nucleotide polymorphisms associated with steroid-induced ocular hypertension

AIM:To access the association of forty-eight single nucleotide polymorphisms(SNPs)identified from Caucasian population with steroid-induced ocular hypertension(OHT)in India population.METHODS:Fifty-four triamcinolone-acetonide(TA)and for ty-seven dexamethasone(Dex)administered subjects were enrolled in the study after a written consent.Intraocular pressure(IOP)values were recorded for a period of 6-month post steroid injections and patients were grouped as steroid-responders(SR:IOP≥21 mm Hg)and non-responders(NR:IOP≤20 mm Hg).Genomic DNA was isolated from peripheral venous blood.Forty-eight SNPs identified in TA treated Caucasian patients by genome wide association study(GWAS)were genotyped using iPLEXTM MassA RRAY among TA as well as Dex administered Indian patients.Genotyping data of 48 general subjects from a previous study were considered as reference controls for statistical analysis.Genotypic frequencies were calculated and P-value,Chi-square and odds ratio at 95%confidenceinterval of group A(steroid treated vs controls),group B(SR vs NR),group C(phenotype correlation:influence of time,severity and gender on IOP rise),were calculated.P<0.05 was considered to be statistically significant.RESULTS:OHT was observed in 50%of TA and 26%of Dex administered patients,respectively.IOP rise was mostly severe(>30 mm Hg)and immediate(<1 wk)among TA-SR patients while it was noticed to be mild(<30 mm Hg)and between 1-2 mo among Dex-SR patients.Logistic regression for risk factor correlation with OHT remained non-significant,hence these factors were not considered as confounding parameters for further analysis.rs133,rs34016742,rs274554,rs10936746,rs274547,rs804854,rs7751500,rs359498,and rs7547448 SNPs significantly varied even after Bonferroni corrections(P<0.0025;group A).rs1879370(TA)and rs6559662(Dex)were significantly(P<0.05)associated with OHT(group B).rs133(severe IOP rise),rs11047639 and rs1879370(male gender),and rs11171569(immediate IOP rise)significantly(P<0.05)influenced the phenotype correlation only among TAOHT patients.However,the significance of these SNPs in group B and phenotype analysis(group C)was lost upon Bonferroni corrections(P<0.0025).CONCLUSION:Prevalence of OHT in study population is observed to be similar to other studies both in TA and Dex treated patients.We can correlate rs34016742 involved in diabetes signaling pathway to the occurrence of ocular edematous and inflammatory conditions.Except rs133 that is involved in neuro-degeneration and myopia occurrence,none of the other SNPs identified in Caucasian population possess any correlation with OHT incidence in TA and Dex administered Indian subjects.

Association of eleven single nucleotide polymorphisms with refractive disorders from Eskisehir,Turkey

AIM:To investigate relationship between refractive errors and eleven single nucleotide polymorphisms(SNPs)in HGF,GC,MFN1,GNB4,and VDR genes in Turkish population.METHODS:A group of 212 participants with myopia(n=91),hyperopia(n=45),and emmetropia(n=76)were investigated in this study.SNPs in HGF,GC,MFN1,GNB4 and VDR genes were studied by Snap Shot technique.RESULTS:The patients in this study consists of 47 female/44 male(age:23.47±4.30)patients with myopia,20 female/25 male(age:31.20±8.02)with hyperopia and 33 female/43 male(age:25.22±6.60)with emmetropia.The genotype distribution of the rs7618348 polymorphism,which was the only statistically significant one between myopia and emmetropia group.The genotype distribution of the rs3819545,rs3735520,rs7041,and rs2239182 polymorphisms,which were statistically significant between hyperopia and emmetropia groups.CONCLUSION:The importance of genetic predisposition to refractive errors with respect to etiology of the disease is revealed.It is known that polymorphism studies may differ because of genetic diversity among populations so larger cohort studies are required in different populations to enlighten the etiology of the refractive errors.

Allele-specific amplification and electrochemiluminescence method for single nucleotide polymorphism analysis

A new approach combined the specificity of allele-specific amplification （ASA） with the sensitivity of electrochemiluminescence （ECL） assay for single nucleotide polymorphism （SNP） analysis was proposed. Briefly, target gene was amplified by a biotin-labeled allele-specific forward primer and a Ru（bpy）3 ^2＋（TBR）-labeled universal reverse primer. Then, the amplicon was captured onto streptavidin-coated paramagnetic beads through biotin label, and detected by measuring the ECL signal of TBR label. Different genotypes were distinguished according to the ECL values of the amplicons by different genotypic primers. K-ras oncogene was used as a target to validate the feasibility of the method. The experiment results show that the different genotypes can be clearly distinguished by ASA-ECL assay. The method is useful in SNP analysis due to its sensitivity,safety, and simplicity.

Single nucleotide polymorphisms of MAGE-A3 gene and its clinical implications in Chinese patients with non-small cell lung cancer(NSCLC)

Background： Available study revealed advanced tumors have a higher expression rate of MAGE-A3 gene which has a lot of single nucleotide polymorphism（SNP） loci with polymorphisms. This study aimed to analyze the allele frequency of SNP loci in MAGE-A3 gene and investigate the relationship between MAGE-A3 gene polymorphisms and clinical factors.Methods： Tumor samples of a cohort of 191 NSCLC patients were collected. EGFR m RNA expression were detected by q RT-PCR. SNPs in whole length of MAGE-A3 gene were detected by direct sequencing. Frequencies of the SNPs were correlated to gene expression, mutation status of EGFR and clinical factors.Results： Sequencing analysis confirmed that allele frequencies of genotypes on SNP loci rs5970360, rs5925210, rs5970361, rs5925211 and rs35123853 were CC（0.681）/CT（0.319）, CC（0.660）/CG（0.340）, CC（0.681）/CA（0.319）, AA（0.984）/AT（0.016） and GG（1.000）/GA（0.000）, respectively, which were different from the frequencies and genotypes of MAGE-A3 in SNP database. Chi-square tests showed the EGFR mR NA expression level had significant correlation with the genotypes of SNP loci rs5970360 and rs5925210. But all frequencies of each MAGE-A3 SNPs were not found significantly different between EGFR mutant and wild type patients. MAGE-A3 gene polymorphisms had no significant effects on survival of NSCLC patients.Conclusions： Chinese patients with NSCLC had different SNP patterns of MAGE-A3 in comparison with those in international SNP database. These MAGE-A3 SNP loci might have not prognostic significance. MAGE-A3 SNP loci rs5970360 and rs5925210 might be predictive for EGFR m RNA expression levels and helpful to the selection of patients for epidermal growth factor receptor（EGFR） targeted immunotherapy.