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PubMed2000

Characterization of early follicular cDNA library suggests evidence for genetic polymorphisms in the inbred strain C108 of Bombyx mori.

Recent work towards the completion of a saturated molecular genetic linkage map for the lepidopteran silkworm, Bombyx mori (n = 28), has provided evidence for existing polymorphisms in the inbred strain C108. Two inbred parental strains, p50 and C108, were crossed to produce the F1 (P/C) hybrid offspring. The populations used in this project were comprised of a combination of 29 F2 (F1 x F1) and 31 reciprocal backcross (P/C x C/C, P/C x P/P) progeny. All restriction fragment length polymorphisms (RFLPs) for the initial analysis were hybridized with anonymous probes derived from a random early follicular cDNA (Rcf) library from Bombyx. A total of 19 Rcf probes were selected as showing scorable codominant polymorphic patterns when screened against F2 and backcross DNAs digested with the restriction enzymes EcoRI, HindIII, or PstI, and Southern blotted to nylon membranes for hybridization. Of the newly reported Rcf probes, 7 (37%) were characterized as producing 'simple' polymorphic patterns, while 12 (63%) were characterized as producing 'complex' polymorphic patterns. Further characterization of the complex patterns subdivided this group into two general classes: polymorphisms that contained an additional allele, and multiple bands that contained an easily scored two banded polymorphism. Because the extra allele class was limited to the (P/C x C/C) backcross progeny, it is suggested that the inbred parental strain C108 harbors polymorphic loci that are inherited in a simple Mendelian fashion. A genetic analysis discussing plausible origins and maintenance of these polymorphisms is presented.

Animals↗

PubMed2003

An alternative fast and convenient genotyping method for the screening of angiotensin converting enzyme gene polymorphisms.

Insertion/deletion (I/D) polymorphisms in intron 16 of the angiotensin converting enzyme gene (ACE) are associated with the plasma angiotensin converting enzyme (ACE) levels, and individuals with the DD allele have been reported to be more susceptible to cardiovascular disease than those without. The conventional genotyping method for the screening of I/D polymorphisms, which involves polymerase chain reaction (PCR)-gel electrophoresis, is laborious and time-consuming. In this study, we assessed the use of TaqMan-PCR genotyping for the screening of I/D polymorphisms as a replacement for the conventional method. We genotyped seven single nucleotide polymorphisms (SNPs) in linkage disequilibrium (LD) with the I/D polymorphisms, and calculated the LD coefficients of the I/D polymorphisms. We found that three polymorphisms, rs4331, rs4334 and rs4341, exhibited the highest LD coefficients (D' = 1.000; r2 = 0.967) and that the genotyping of rs4341 by the TaqMan-PCR method yielded the best discrimination among the different genotypes. Genotyping of 511 samples took only 2 h and the amount of DNA required for each test was only 6 ng by the TaqMan-PCR method using rs4341. In the course of this study, we identified a novel additional polymorphism (a deletion of six amino acids) in exon 13, near rs4316. The deletion allele encoded the testicular ACE, but not the plasma ACE. We concluded that genotyping of the rs4341 ACE polymorphism by the TaqMan-PCR method is a fast and convenient alternative method for direct I/D genotyping. We also concluded that testicular ACE may manifest a deletion of six amino acids that may result in deleterious function of this enzyme.

Adult↗

PubMed2003

A novel variable number of tandem repeat polymorphism of the renin gene and essential hypertension.

The aims of the present study were to find new genetic markers of essential hypertension (EH) and to investigate relationships between EH and polymorphisms of the renin gene. Using single strand conformation polymorphism, we discovered a new variable number of tandem repeat (VNTR) polymorphism in intron 7 that is 18 bp upstream from the boundary with exon 8. Nucleotide sequencing revealed that this VNTR polymorphism is a tandem repeat of the 4-nucleotide sequence TCTG. There were 6 alleles of this VNTR polymorphism, ranging from 7 repeats to 12 repeats. We analyzed the association between EH and this VNTR polymorphism. There was no significant difference in the overall distribution of this VNTR polymorphism between the EH and normotensive subjects. In summary, we discovered a novel VNTR polymorphism in the renin gene, and this polymorphism was not associated with EH.

Adult↗

PubMed2004

Effect of CYP1A1 gene polymorphisms on estrogen metabolism and bone density.

UNLABELLED: In this study, we evaluated the effect of polymorphisms of the CYP1A1 gene, linked to hormone-related cancers, on estrogen metabolism and BMD. We found that variants carrying the A allele (CA and AA) for the C4887A polymorphism have a significantly higher degree of estrogen catabolism and lower femoral BMD. INTRODUCTION: Polymorphisms of the CYP1A1 gene, one of the key enzymes that metabolize estrogen, have been linked with hormone-related cancers. We investigated the impact of these polymorphisms on estrogen metabolism and BMD, which is another hormone-dependent health issue. MATERIALS AND METHODS: One hundred seventy postmenopausal women (mean age, 63.5 +/- 0.6 years) participated in the study, but analysis was limited to 156 white women. Genotyping was performed by restriction fragment length polymorphism analysis, urinary estrogen metabolites by enzyme immunoassay, serum estradiol by ultrasensitive radioimmunoassay, serum sex hormone-binding globulin by immunoradiometric assay, and BMD by DXA. Differences in the levels of urinary metabolites and BMD among the different variants were analyzed by analysis of covariance, whereas differences in free estradiol index, urinary N-telopeptide of type 1 collagen (NTx), and bone size were compared by one-way ANOVA. RESULTS: We found that subjects carrying the A allele (CA or AA) for the C4887A polymorphism of the CYP1A1 gene have significantly lower free estradiol index (0.323 +/- 0.08 versus 0.506 +/- 0.04; p = 0.04; pmol/nmol) and higher levels of total urinary estrogen metabolites (ng/mg Cr) than CC subjects (27.92 +/- 2.03 versus 21.15 +/- 1.04; p = 0.03), suggestive of an accelerated estrogen catabolism in these (CA + AA) individuals. They also had significantly lower BMD (g/cm2) in all regions of the femur than subjects with the CC genotype, (total hip: 0.809 +/- 0.02 versus 0.865 +/- 0.01; neck: 0.671 +/- 0.02 versus 0.722 +/- 0.01; trochanter: 0.614 +/- 0.02 versus 0.656 +/- 0.01; and intertrochanter: 0.969 +/- 0.03 versus 1.039 +/- 0.01; all p < 0.05). No significant effect of this gene polymorphism was detected on lumbar spine BMD. Urinary NTx, a marker for bone resorption, was also significantly higher in the CA + AA compared with the CC variants (186.09 +/- 16.15 versus 124.00 +/- 11.87 nmol of bone collagen equivalent/mmol of creatinine; p = 0.003). Genotype frequencies for this polymorphism showed CC as the most common genotype (127/156), followed by CA (28/156), whereas AA was rare (1/156). CONCLUSION: Women with the A allele seem to have increased estrogen catabolism, as indicated by higher urinary estrogen metabolites and lower free estradiol index. This is associated with increased bone resorption and lower femoral BMD in those with the A allele. Our data, therefore, suggest that, through its effect on the rate of estrogen catabolism, the C4887A polymorphism of the CYP1A1 gene may represent a possible genetic risk factor for osteoporosis.

Absorptiometry, Photon↗

PubMed2002

Synergistic effect of thrombomodulin promoter -33G/A polymorphism and smoking on the onset of acute myocardial infarction.

Thrombomodulin is an endothelial cell surface receptor for thrombin. It plays an important role in the regulation of blood coagulation by decreasing thrombin activity and activating protein C. This study examined the possible association between the thrombomodulin -33G/A polymorphism and acute myocardial infarction. We recruited 278 patients (mean age 57.5 years, 241 men) with documented myocardial infarction and 450 age- and sex-matched control subjects. Polymerase chain reaction and single-strand conformation polymorphism was used to define the thrombomodulin -33G/A polymorphism. The frequency of the thrombomodulin GA+AA genotype among patients with myocardial infarction was higher than that in control subjects (22.7% vs. 16.2%, odds ratio [OR] 1.5, 95% confidence interval [CI] 1.0 to 2.2). The -33G/A polymorphism (GA+AA genotype) was significantly associated with myocardial infarction (OR 1.6, 95% CI 1.1 to 2.5) as was hypertension, diabetes mellitus and smoking. Among young myocardial infarction patients (age < or =45 years, n = 72), the frequency of -33G/A polymorphism was more significantly higher than that in control subjects (29.2% vs. 16.2%, OR 2.1, 95% CI 1.2 to 3.8). The -33G/A polymorphism (OR 2.3, 95% CI 1.3 to 4.1) and smoking (OR 4.5, 95% CI 2.5 to 7.9) were the only independent risk factors for young myocardial infarction. Furthermore, among patients who did not smoke, the polymorphism was associated with a nonsignificant increase in the risk of young myocardial infarction (OR 1.9, 95% CI 0.6 to 5.6); whereas, in the presence of smoking, the increase was statistically significant (OR 2.3, 95% CI 1.2 to 4.7). Smoking carriers of the thrombomodulin -33G/A polymorphism had a nearly 10-fold increased risk of young myocardial infarction (OR 9.8, 95% CI 4.3 to 22.4) when compared with nonsmoking non-carriers. We concluded that there was a significant association between the thrombomodulin -33G/A polymorphism and myocardial infarction in our population, especially in young patients. The clinical effect of this genetic factor was enhanced by smoking.

Adult↗

PubMed2004

[Exploring the possibility of a relationship between polymorphism in TIM-1 and allergic asthma in children of the Hans from Hubei province of China].

OBJECTIVE: To investigate two polymorphism sites of exon 4 in T cells, immunoglobulin domain and mucin domain protein-1 (TIM-1, also human hepatitis A virus cellular receptor-1) and to detect whether they are associated with allergic asthma in children of the Hans in Hubei province of China. METHODS: The ins/del and IVS 8+9 G/A polymorphisms in TIM-1 were detected with polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). The genotypes and alleles frequencies were calculated and analyzed. RESULTS: (1) Two alleles, a wide type del and a variant allele ins were identified in the TIM-1 exon 4. The genotype frequencies of ins/ins, ins/del, and del/del were 0.065,0.326, and 0.608 respectively in the healthy population of the Hans. Another IVS 8/9 G/A polymorphism was also found. The genotype frequencies of A/A, G/A, G/G were 0.022, 0.196 and 0.783, respectively. (2) The genotype frequencies of ins/ins, ins/del, and del/del were 0.045, 0.318, and 0.636 respectively in the allergic asthma population in children of the Hans. No significant difference in ins/del polymorphism was found between allergic asthma patients and control subjects. Another 8/9 IVS G/A polymorphism was also found. The genotype frequencies of A/A, G/A and G/G were 0.009, 0.209 and 0.782 respectively in allergic asthma. No significant difference in IVS G/A polymorphism was found between allergic asthma patients and control subjects. CONCLUSION: The genotype and allele frequencies in the two polymorphism sites in TIM-1 in healthy population of the Hans from Hubei province of China were similar to those in Japanese. The two polymorphism sites of TIM-1 are not associated with allergic asthma in Chinese children.

Adolescent↗

PubMed2006

[Correlation of genetic polymorphisms in DNA repair genes ADPRT and XRCC1 to risk of gastric cancer].

BACKGROUND & OBJECTIVE: Adenosine diphosphate ribosyl transferase (ADPRT) and X-ray repair cross-complementing 1 (XRCC1) are 2 major DNA base excision repair (BER) proteins and act interactively in stimulating and executing BER processes. Polymorphisms of ADPRT 762Val-->Ala and XRCC1 399Arg-->Gln have been verified to associate with altered protein function and BER activity. This study was to examine the contribution of these 2 polymorphisms, alone or in combination, to the risk of developing gastric cancer. METHODS: A total of 236 patients with gastric cancer and 708 cancer-free controls were genotyped for the 2 polymorphisms by polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) method. Odds ratio (OR) and 95% confidence interval (CI) were calculated using unconditional logistic regression model to evaluate the impact of these 2 polymorphisms on the risk of developing gastric cancer. RESULTS: The subjects having the ADPRT Ala/Ala genotype had an OR of 2.07 (95% CI=1.33-3.21; P=0.001) compared with those having the Val/Val genotype. Gene-gene interaction of ADPRT and XRCC1 polymorphisms increased the risk of gastric cancer in a super-multiplicative manner, with an OR of 5.32 (95% CI=1.12-28.57) for the presence of both ADPRT 762Ala/Ala and XRCC1 399Gln/Gln genotypes, although the XRCC1 polymorphism itself was not associated with the risk of gastric cancer. CONCLUSION: The ADPRT 762Val-->Ala polymorphism plays an important role in the development of gastric cancer, and the XRCC1 399Arg-->Gln polymorphism may serve as a risk modifier.

ADP Ribose Transferases↗

PubMed2006

[Study on the genetic polymorphisms of human glutathione-S-transferase A1 in Hakka population in South China].

OBJECTIVE: Glutathione-S-transferase A1 (GSTA1) is one of the major phase II detoxification enzymes in the cytosol, which genetic polymorphisms distribution is different in different ethnic, national and regional population. Up to now, GSTA1 genetic polymorphisms has been rarely reported in China. The purpose of the study was to investigate the distribution of genetic polymorphisms of human GSTA1 in Hakka population in South China. METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) were used to identify the genotypes of GSTA1 gene and the data were analyzed with SPSS10.0 software. RESULTS: The GSTA1 genetic polymorphisms were detected in 480 samples. The frequency of GSTA1 * A/ * A,GSTA1 * A/ * B and GSTA1 * B/ * B were 77.1%, 21.7% and 1.2% respectively. And the GSTA1 genetic polymorphism distribution was in accordance with the Hardy-Weinberg equilibrium rule. There were no difference in the GSTA1 genetic polymorphisms among the different groups of age or gender. Logistic regression analysis showed that there were no association between the GSTA1 genetic polymorphism and family history of hypertension, coronary heart disease, stroke, lung cancer and nasopharyngeal cancer, et al. CONCLUSION: The GSTA1 gene existed polymorphism among Hakka in South China.

Adolescent↗

PubMed2002

DNA repair gene ERCC1 and ERCC2/XPD polymorphisms and risk of squamous cell carcinoma of the head and neck.

OBJECTIVE: To determine the effect of the ERCC1 C8092A polymorphism and the ERCC2/XPD G23591A polymorphism on the risk of squamous cell carcinoma of the head and neck (SCCHN). DESIGN: A hospital-based case-control study. SUBJECTS: A total of 330 newly diagnosed case subjects with SCCHN and 330 cancer-free control subjects matched on age (+/- 5 years), sex, smoking status, and alcohol use. All subjects were non-Hispanic whites. METHODS: After informed consent was obtained, blood was drawn for genotyping. The ERCC1 C8092A polymorphism was typed by single-strand conformational polymorphism analysis. The ERCC2/XPD G23591A polymorphism was typed by polymerase chain reaction-based restriction fragment length polymorphism analysis with the enzyme StyI. The chi(2) analysis was used to assess differences in genotype and allele frequencies. Multivariate logistic regression analysis was performed to estimate the risk of SCCHN for individuals having these genotypes after adjustment for age, sex, tobacco smoking, and alcohol use. RESULTS: The DNA was available and genotyping was ultimately successful for 313 case subjects and 313 control subjects. The ERCC1 8092CC genotype and the ERCC2/XPD 23591A allele were associated with nonsignificantly increased risks of SCCHN: odds ratios, 1.15 (95% confidence interval [CI], 0.84-1.59) and 1.28 (95% CI, 0.93-1.76), respectively, whereas having both risk genotypes was associated with an even higher risk of SCCHN: odds ratio, 1.78 (95% CI, 0.99-3.17). When considering both polymorphisms, we found a significant allele dose effect (P =.04). CONCLUSIONS: These 2 polymorphisms may contribute to the risk of SCCHN, but larger studies are needed to confirm their role in SCCHN. Combining common DNA repair gene polymorphisms into models of genetic risk of SCCHN may improve risk estimates.

Adult↗

PubMed2006

Increased prevalence of interleukin-1 receptor antagonist gene polymorphism in patients with chronic rhinosinusitis.

OBJECTIVE: To assess the association of the interleukin (IL)-1beta and the IL-1 receptor antagonist (IL-1Ra) gene polymorphisms with chronic rhinosinusitis (CRS). DESIGN: Genotyping of the 2 IL-1beta gene (IL1B) polymorphisms (promoter and exon) and the IL-1Ra gene (IL1RN) polymorphism (intron 2) was performed using polymerase chain reaction and restriction length fragment polymorphism analyses. SETTING: Prospective study, tertiary medical center. PATIENTS: The study population comprised 88 consecutive adult Taiwan-Chinese patients who met stringent criteria for CRS and received endoscopic sinus surgery and 103 healthy volunteers of the same ethnicity and similar age range. Of the 88 patients, 61 had CRS with nasal polyps, while the other 27 had CRS without nasal polyps. RESULTS: There were significant differences in the distribution of the IL1RN polymorphism between the control subjects and patients with CRS (P<.05). The II allele of IL1RN occurred more frequently in the CRS patient group, and the odds ratio for subjects with I/II genotype was 3.39 (95% confidence interval, 1.25-9.18). In the case of CRS without nasal polyps, the odds ratio for subjects with I/II genotype was further increased to 4.75 (1.39-16.25). There was no association between the other 2 polymorphisms of IL1B and CRS. CONCLUSION: Increased prevalence of IL1RN polymorphism in patients with CRS suggests that this polymorphism, or a polymorphism in linkage disequilibrium with it, may be involved in the development of CRS.

Adult↗

PubMed2003

Relationship between functional dopamine D2 and D3 receptors gene polymorphisms and neuroleptic malignant syndrome.

Our previous study has suggested that the TaqI A polymorphism of dopamine D2 receptor gene (DRD2) is associated with the predisposition to neuroleptic malignant syndrome (NMS). However, the specificity of this polymorphism as a predictor of NMS dose not seem to be sufficient enough. Meanwhile, it has been shown that the non-carriers of Del allele of the -141C Ins/Del polymorphism in the promoter region of DRD2 have lower dopamine D2 receptor in the brain than the carriers. In addition, dopamine D3 receptor gene has a Ser(9)Gly polymorphism, which may alter the receptor function. The present study examined the association between these three polymorphisms and the development of NMS to investigate if a combination of these polymorphisms could increase the specificity as markers for NMS. The subjects were 17 psychiatric patients who had developed NMS (13 patients with schizophrenia, 3 with major depression, and 1 with dementia of the Alzheimer's type) and 163 schizophrenic patients who had never developed this syndrome. The frequency of the A1 allele was significantly (P = 0.012) higher in the patients who had developed NMS (59%) than in the patients who had not (35%). The proportion of the A1 carriers was significantly (P = 0.003) higher in the patients with NMS (16/17: 94%) than in those without the syndrome (93/163: 57%). However, no significant differences were found in the allele and genotype frequencies of the other two polymorphisms between the two groups. The present study suggests that only the TaqI A polymorphism is at least partly useful as a predictor of NMS, but the -141 C Ins/Del and Ser(9)Gly polymorphisms are not.

Adult↗

PubMed2003

Polymorphism analysis of HOPA: a candidate gene for schizophrenia.

HOPA is a 25 kb Xq13 gene that codes for a member of the thyroid receptor co-activator protein (TRAP) family of nuclear receptor co-activators. In our prior research, polymorphisms in the opposite paired (Opa) domain of HOPA have been associated with a syndrome of aberrant behavior, most prominently psychosis, and hypothyroidism. These Opa domain polymorphisms are intriguing because subsequent research has demonstrated that changes in the Opa domain of the C. elegans orthologue of HOPA results in altered neurogenesis and release of transcriptional suppression. In an effort to determine whether other allelic polymorphisms in this gene exist and may potentially contribute to increased susceptibility to neuropsychiatric illness, we have performed single stranded conformational polymorphism (SSCP) analysis of all 45 exons and each of the two potential promoter regions of HOPA using DNA from a panel of patients with psychosis. We found a rare promoter polymorphism in an individual with schizoaffective disorder and extremely low thyroid stimulating hormone (TSH). The most common exonic polymorphism in HOPA is the previously demonstrated HOPA(12 bp) polymorphism. Transmission disequilibrium analysis of the HOPA(12 bp) polymorphism showed segregation with affected status in six of eight instances. We suggest that this evidence supports previous associations of HOPA(12 bp) with a broad range of neuropsychiatric illness and conclude that further studies of this uncommon polymorphism are merited.

Alleles↗

PubMed2006

Exploring SNP-SNP interactions and colon cancer risk using polymorphism interaction analysis.

Several single nucleotide polymorphisms (SNPs) in genes derived from distinct pathways are associated with colon cancer risk; however, few studies have examined SNP-SNP interactions concurrently. We explored the association between colon cancer and 94 SNPs, using a novel approach, polymorphism interaction analysis (PIA). We developed PIA to examine all possible SNP combinations, based on the 94 SNPs studied in 216 male colon cancer cases and 255 male controls, employing 2 separate functions that cross-validate and minimize false-positive results in the evaluation of SNP combinations to predict colon cancer risk. PIA identified previously described null polymorphisms in glutathione-S-transferase T1 (GSTT1) as the best predictor of colon cancer among the studied SNPs, and also identified novel polymorphisms in the inflammation and hormone metabolism pathways that singly or jointly predict cancer risk. PIA identified SNPs that may interact with the GSTT1 polymorphism, including coding polymorphisms in TP53 (Arg72Pro in p53) and CASP8 (Asp302His in caspase 8), which may modify the association between this polymorphism and colon cancer. This was confirmed by logistic regression, as the GSTT1 null polymorphism in combination with either the TP53 or the CASP8 polymorphism significantly alter colon cancer risk (p(interaction) < 0.02 for both). GSTT1 prevents DNA damage by detoxifying mutagenic compounds, while the p53 protein facilitates repair of DNA damage and induces apoptosis, and caspase 8 is activated in p53-mediated apoptosis. Our results suggest that PIA is a valid method for suggesting SNP-SNP interactions that may be validated in future studies, using more traditional statistical methods on different datasets.

Aged↗

PubMed1996

Systematic screening for genetic polymorphism in human platelet glycoprotein Ibalpha.

Glycoprotein Ibalpha (GP Ibalpha; CD 42b; hereafter GPIBA) is a component of the cell surface receptor for the von Willebrand factor (vWf) on platelets. Immunizations against various platelet surface antigens play a major role in neonatal alloimmune thrombocytopenia and in post-transfusion purpura. Only one antigenic polymorphism in GPIBA has thus far been established: the HPA-2 (Ko) alloantigen system. To screen other polymorphisms in GPIBA systematically, we analyzed the whole coding sequence of the GPIBA gene in 50 Finnish blood donors using the single-strand conformation polymorphism method. In addition to the known polymorphisms, we detected three others. Sequencing of the gene segments carrying the new polymorphisms revealed that none of them changed the predicted amino acid sequence. Polymorphism designated RS was located five base pairs upstream from the initiation codon at position 3064 and had the gene frequency of 16% for R and 84% for S, respectively, in the Finnish population, and it was detectable by the restriction enzyme Hae III. The EF polymorphism was at position 3842 (Asn242) and the gene frequencies were 97% for E and 3% for F. The KL polymorphism was at position 4142 (Arg342) and the gene frequencies were 98% for K and 2% for L. The five polymorphic positions in GPIBA formed altogether six different alleles of the gene. The data suggest that there are only a few variable amino acids in GPIBA.

Alleles↗

PubMed2006

Significance of the RET proto-oncogene polymorphisms in Turkish sporadic medullary thyroid carcinoma patients.

Several single nucleotide polymorphisms (SNP) of the RET gene have been identified in medullary thyroid carcinoma (MTC) patients as well as in the general population. However, the relevance of SNP for MTC patients is still controversial, whether these allelic variants play other interacting, predisposing or modifying roles in clinical behavior of MTC. The aim of this work is to elaborate allelic frequencies of the RET proto-oncogene polymorphisms in Turkish sporadic MTC patients and to demonstrate if there is an association between SNP and the clinical disease features, specifically the age at onset of MTC and lymph node involvement at diagnosis. We analyzed the allelic frequencies of SNP of the exon 11, 13, 14 and 15 of the RET proto-oncogene in blood samples from 50 sporadic MTC patients, using the polymerase chain reaction methodology followed by DNA sequencing. The observed allelic frequencies were 24% for G691S polymorphism in exon 11, 29% for L769L polymorphism in exon 13, 5% for S836S polymorphism in exon 14, and 26% for S904S polymorphism in exon 15. These frequencies are similar to those reported in other countries. We did not observe any significant association of all four SNP with the age at onset of MTC. Our results indicate a possible association between the presence of lymph node involvement at the time of diagnosis (extent of disease) and L769L or S836S polymorphism. However, it is not possible to draw definitive conclusions that these two polymorphisms play a significant role in clinical behavior of MTC. Further studies are needed to evaluate the role of this polymorphism in the clinical behavior of MTC.

Adult↗

PubMed2004

-717A>G polymorphism of human C-reactive protein gene associated with coronary heart disease in ethnic Han Chinese: the Beijing atherosclerosis study.

Serum C-reactive protein (CRP) has been strongly implicated in the pathogenesis of coronary heart disease (CHD). We report here on the association between gene coding for CRP and CHD in the ethnic Han population of China. For this purpose two polymorphisms of -717A>G and +2147A>G of the CRP gene were identified by direct sequencing of genomic DNA derived from 48 randomly selected patients and these were further investigated for associations with CHD in 619 male patients and 615 age-matched male normal controls. The frequency of A allele carriers of -717A>G polymorphism was significantly higher in patients than in controls by univariate analysis. After controlling for other risk factors the association between this polymorphism and CHD remained significant by multivariate logistic regression analysis. Individuals carrying the -717A allele had an approx. 6.8-fold higher risk of developing CHD (odds ratio 6.84 compared with those not carrying this allele). Haplotype analysis confirmed the results of individual polymorphism analyses. However, the resolution of effect size is poor, which may be due to the deficiency in sample size of this study. Neither polymorphism was observed to have an influence on serum CRP level. Since the frequency difference between CHD cases and controls for the -717A allele carriers is only 2.28%, and homozygosity for -717G occurs in only 1.78% of subjects, -717 A>G polymorphism is not a major determinant of population genetic risk of CHD in the Chinese population. The association of this polymorphism with CHD supports the belief that carriers of -717A allele of the CRP gene are genetically predisposed to CHD in the Chinese Han population, and it remains possible that this polymorphism is in disequilibrium with one as yet unidentified functional polymorphism in the vicinity.

C-Reactive Protein↗

PubMed2005

Identification of novel polymorphisms in the glucokinase and glucose-6-phosphatase genes in infants who died suddenly and unexpectedly.

Sudden and unexpected infant deaths can be unexplained [sudden infant death syndrome (SIDS)] or explained (non-SIDS) but risk factors including lower birthweight are similar in both groups. Mutations in the glucokinase (GK) gene result in Maturity Onset Diabetes of the Young type 2 (MODY 2) and are associated with lower birthweight. Low hepatic glucose-6-phosphatase (G6PC1) expression occurs in both low birthweight and SIDS infants. We investigated whether polymorphisms are prevalent in the GK and G6PC1 genes in infants who died suddenly and unexpectedly. Mutation analysis was performed by polymerase chain reaction (PCR) and denaturing high-performance liquid chromatography (DHPLC) in samples from 126 infants who died suddenly and unexpectedly (78 SIDS, 48 non-SIDS) and from 70 healthy, living infants. G6PC1 promoter polymorphism significance was investigated by transfection of reporter gene constructs into a H4IIE cell line. Heterozygous GK polymorphisms were identified in 17.9% of SIDS and 20.8% of non-SIDS infants: two rare silent polymorphisms, Y215Y and S263S, in the coding region; a third rare polymorphism, -45G>A, in the hepatic promoter and the most prevalent polymorphism, c.484-29G>C, in a non-coding region upstream from the intron 4-exon 5 junction. A novel heterozygous polymorphism -77G>A in the G6PC1 promoter in 6.3% of non-SIDS and 2.9% of control infants decreased basal G6PC1 promoter activity (p<0.001). We describe three novel polymorphisms in the GK gene, S263S, -45G>A, and a common (14.3%) intronic substitution, c.484-29G>C, in infants who died suddenly and unexpectedly. We identified the first G6PC1 promoter polymorphism, which lowers expression, potentially increasing risk of hypoglycaemia and hence risk of sudden and unexpected death.

Animals↗

PubMed2001

Gene polymorphisms of immunoregulatory cytokines and angiotensin-converting enzyme in Wegener's granulomatosis.

Wegener's granulomatosis is a granulomatous and vasculitic disease of unknown origin. Gene polymorphisms are known to affect phenotypes of numerous diseases. Polymorphisms within the angiotensin-converting enzyme (ACE), transforming growth factor-beta1 (TGF-beta1), and interleukin-10 (IL-10) genes are suspected to modify the course of granulomatous disorders. We examined whether the genotype frequencies of the named polymorphisms differ in Wegener's granulomatosis from those in healthy controls. Thirty-nine patients with Wegener's granulomatosis were genotyped for the deletion/insertion polymorphism in intron 16 of the ACE gene, a biallelic polymorphism in codon 25 of the TGF-beta1 gene and a biallelic polymorphism at position -1082 of the IL-10 gene and compared with healthy blood donors. For the ACE polymorphism no significant differences were detected neither in the allele frequencies nor in the genotype frequencies. For TGF-beta1 a trend to genotype CG was found. The most interesting result was the observed, significant shift to genotype AA of the IL-10 polymorphism in Wegener's granulomatosis. IL-10 and TGF-beta1, immunoregulatory cytokines capable of down-regulating T helper cell type 1 response, showed a significant shift or a trend, respectively towards genotypes associated with reduced cytokine release, leading to the hypothesis that different immunoregulatory cytokine patterns dependent on gene polymorphisms might be involved in the pathogenesis of Wegener's granulomatosis.

Adult↗