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Evidence that polymorphism of the angiotensin I converting enzyme gene may be related to idiopathic dilated cardiomyopathy in the Chinese population.

Angiotensin I-converting enzyme (ACE) is responsible for the production of angiotension II and the breakdown of kinins, leading to increased blood pressure (BP), induction of vascular smooth muscle cell proliferation, and the stimulation of myocardial-cell hypertrophy. A 287 bp insertion/deletion polymorphism in intron 16 of the ACE gene was examined by polymerase chain reaction in a cross-sectional study of 35 patients with idiopathic dilated cardiomyopathy (IDC) and 35 patients with normally functioning hearts (NT). Compared with the deletion/deletion (D/D) frequency in the control population, the frequency of the deletion allele was 0.757 in IDC patients and 0.600 in NTs; the difference between observed alleles in all subjects in each group was significant (x2 = 3.96; P < 0.05). The data thus provide evidence in favor of an association between idiopathic dilated cardiomyopathy and a polymorphism at the ACE locus (17q23), thus implicating this locus, and possibly a genetic variant of ACE, itself, in human idiopathic dilated cardiomyopathy.

Adult↗

Association of the serotonin transporter gene with sudden infant death syndrome: a haplotype analysis.

Serotonergic receptor binding in the arcuate nucleus, n. raphé obscurus, and other medullary regions is decreased in sudden infant death syndrome (SIDS) cases. Further, an insertion/deletion polymorphism in the promoter region of the serotonin transporter protein (5-HTT) gene has recently been associated with risk of SIDS. This polymorphism differentially regulates 5-HTT expression, with the long allele (L), the SIDS-associated allele, being a more effective promoter than the short allele (S). To further elucidate the role of the 5-HTT gene in SIDS, we investigated the 5-HTT intron 2 polymorphism, which also differentially regulates 5-HTT expression with the 12 repeat allele being the more effective promoter. In a cohort of 90 SIDS cases (44 African-American and 46 Caucasian) and gender/ethnicity-matched controls, significant positive associations were found between SIDS and the intron 2 genotype distribution (P-value = 0.041) among African-American SIDS vs. African-American controls, specifically with the 12/12 genotype (P-value = 0.03), and with the 12 repeat allele (P-value=0.018). The frequency of the 12/12 genotype and 12-repeat allele was significantly different (P < 0.001) between the African-American and Caucasian SIDS cases. Furthermore, the promoter and intron 2 loci were in significant linkage disequilibrium, and the L-12 haplotype was significantly associated with SIDS in the African-American (P = 0.002) but not Caucasian (P = 0.117) subgroups. These results indicate a relationship between SIDS and the 12-repeat allele of the intron 2 variable number tandem repeat of the 5-HTT gene in African-Americans, and a significant role of the haplotype containing the 12-repeat allele and the promoter L-allele in defining SIDS risk in African-Americans. These data, if confirmed in larger studies, may begin to explain the differences in SIDS incidence by ethnicity, suggest a role for levels of 5-HTT expression in generation of SIDS susceptibility, and provide an important tool for identifying at-risk individuals and estimating the risk of recurrence.

Black or African American↗

Association between the interleukin-1 receptor antagonist polymorphism and ulcerative colitis with younger age at diagnosis.

The VNTR polymorphism in intron 2 of the interleukin-1 receptor antagonist (IL-1RA) gene has been shown associated with ulcerative colitis (UC) in some populations. This study aimed to assess the relationship between the IL-1RA polymorphism and UC in a Japanese population. Genotyping was carried out with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for 468 DNA specimens from 239 healthy volunteers and 229 patients with UC. Genotype distribution was compared between cases and controls, and association of patients' genotype with clinical parameters was evaluated. No significant difference of genotype distribution was found between UC patients and healthy controls. However, when the relation of the carriage rate of allele 2 with clinical parameters was evaluated by Fisher's exact test, it was found that the allele 2 carriage rate was higher in patients with lower ages at diagnosis (< 30) than those with higher ages (> or =30) (odds ratio (OR), 5.049; 95% confidence interval (CI), 1.667-15.288; P= 0.0020). In addition, it tended to be higher in patients with pancolitis type than those with other types restricted to the distal or left-sided colon (OR, 3.005; 95% CI, 1.186-7.616; P=0.0256). These data suggest that the IL-1RA polymorphism is associated with UC with younger age at diagnosis.

Adult↗

The eNOS gene polymorphism does not have a major impact on lipid parameters and premature coronary artery disease in Caucasian women.

Endothelial nitric oxide synthase (eNOS) catalyzes the formation of nitric oxide (NO) which has vasodilatory, antithrombotic, antiinflammatory and antiproliferative actions through which NO regulates blood pressure and modulates the process of atherosclerosis. Genetic polymorphism of the eNOS gene has been identified in several studies as a risk factor for cardiovascular diseases. In this case-control study we examined a possible association of the polymorphism in intron 4 (4a/b) of the eNOS gene (eNOS 4a/b) on coronary artery disease (CAD) risk in 151 Slovenian women with premature CAD (younger than 65 years) and in 109 women without CAD. The eNOS 4a/b polymorphism was analysed by PCR reaction. CAD in women was confirmed by coronary angiography. An aged-matched control group was without a history of symptomatic CAD. The frequency of 4a/b genotypes did not differ between patients and controls: in CAD patients the frequencies of the 4aa, 4ab, or 4bb genotype were 4.0%, 27.2%, or 68.8%, respectively, and in controls the genotype frequencies were 6.4%, 26.6%, or 67.0%, respectively. In our study there were no differences in lipid parameters (total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol and triglycerides) between the subjects with the aa genotype and the subjects with the ab or bb genotype. Also, there was no association between the rare genotype aa and an increased risk of CAD in current and ex-smokers, and in hypertensive individuals. In this study we found that the eNOS 4a/b polymorphism was not associated with premature CAD (OR 0.7; 95% CI 0.2-3.7; p = 0.7), but the clustering of classical risk factors has a major impact on premature CAD in Caucasian women.

Case-Control Studies↗

[Endothelial nitric oxide synthase gene minisatellite polymorphism: study in populations of the Volga-Ural region and analysis of associations with myocardial infarct and essential hypertension].

The 27-bp tandem repeat polymorphism in intron 4 of the endothelial nitric oxide synthase gene (eNOS) in populations of the Volga-Ural region was studied by means of polymerase chain reaction. In Russians and Tatars, the possible association of this polymorphism with coronary heart disease complicated by either myocaridal infarction or by essential hypertension was examined. Russians with essential hypertension associated with hypertrophy of the left ventricle displayed a statistically significant increase of the eNOS4A/B genotype and the A allele frequencies along with the decrease of the frequencies of the eNOS4B/B genotype and the B allele. In Tatars survived from myocardial infarction and with the risk of cardiovascular diseases (smoking or burdened heredity), a statistically significant increase of the frequencies of the eNOS4A/B genotype and the A allele was observed. Thus, in Russians the eNOS4A/B genotype was associated with the development of essential hypertension, while in Tatars it was associated with the risk of myocardial infarction.

Gene Frequency↗

Association of polymorphism at the type I collagen (COL1A1) locus with reduced bone mineral density, increased fracture risk, and increased collagen turnover.

OBJECTIVE: To examine the relationship between a common polymorphism within intron 1 of the COL1A1 gene and osteoporosis in a nested case-control study. METHODS: We studied 185 healthy women (mean +/- SD age 54.3+/-4.6 years). Bone mineral density (BMD) was measured using dual x-ray absorptiometry, and fractures were determined radiographically. The COL1A1 genotype was assessed using the polymerase chain reaction and Bal I endonuclease digestion. RESULTS: Genotype frequencies were similar to those previously observed and in Hardy-Weinberg equilibrium: SS 61.1%, Ss 36.2%, and ss 2.7%. Carriage of at least one copy of the "s" allele was associated with a significant reduction in lumbar spine BMD (P = 0.02) and an increased risk of total fracture (P = 0.04). Urinary pyridinoline levels were significantly elevated in those with the risk allele (P < 0.05). CONCLUSION: These data support the findings that the COL1A1 gene polymorphism is associated with low BMD and fracture risk, and suggest a possible physiologic effect on total body turnover of type I collagen.

Absorptiometry, Photon↗

Identification of PTEN/MMAC1 alterations in uncultured melanomas and melanoma cell lines.

A novel tumor suppressor gene, PTEN/MMAC1, has been recently shown to be mutated in gliomas, breast, prostate, kidney cancers and melanomas. Loss-of-heterozygosity studies in melanoma have suggested the presence of at least one chromosome 10q locus lost early in tumor progression. In this study, we screened 45 melanoma cell lines and 17 paired uncultured metastatic melanoma and peripheral blood specimens for PTEN/ MMAC1 alterations using PCR-SSCP and direct sequencing. We found nine melanoma cell lines with homozygous deletions (five with intragenic loss) and four cell lines with mutations (one nonsense and one frameshift; two intronic); from among our uncultured melanoma specimens, we found one tumor with a somatic 17 bp duplication in exon 7 leading to a premature stop codon and one tumor with a possible homozygous deletion. Furthermore, we have identified a novel intragenic polymorphism within intron 4 of PTEN/MMAC1. Taken together, these data suggest that PTEN/MMAC1 may be a chromosome 10q tumor suppressor important in melanoma tumor formation or progression.

Chromosomes, Human, Pair 10↗

Association of the CYP17 gene and CYP19 gene polymorphisms with risk of endometriosis in Japanese women.

BACKGROUND: To investigate whether polymorphisms of CYP17 and CYP19 genes are associated with the risk of endometriosis, we analysed the frequency and distribution of a single nucleotide polymorphism at the 5' untranslated region of the CYP17 gene, and a tetranucleotide (TTTA) tandem repeat polymorphism and a 3 bp insertion (I)/deletion (D) polymorphism in intron 4 of the CYP19 gene. METHODS: We studied 140 patients with endometriosis, 67 with adenomyosis and/or leiomyomas and 177 healthy control women. RESULTS: The distribution of the genotypes of CYP17 and alleles of the TTTA repeat polymorphism of CYP19 were not significantly different between the groups. In contrast, an increased frequency of the D/D genotype was observed in the endometriosis group as compared with the control group (D/D genotype versus I/I plus I/D genotypes; corrected P = 0.024). This was more evident in the endometriosis subgroups with chocolate cysts (corrected P = 0.043) and at severe clinical stages (corrected P = 0.035). CONCLUSIONS: The results suggest that the 3 bp I/D polymorphism of the CYP19 gene may be weakly associated with the susceptibility of endometriosis in a Japanese population.

Adult↗

Polymerase chain reaction-heteroduplex (PCR-HD) polymorphism within the bovine STAT5A gene.

Signal transducers and activators of transcription (STATs) are transcription factors mediating signals of various hormones and cytokines. STAT5A, previously known as the mammary gland factor (MGF), mediates the action of prolactin on milk protein gene expression in mammary epithelial cells. We used polymerase chain reaction-heteroduplex (PCR-HD) and sequencing methods for detection of nucleotide sequence polymorphism in intron 15 of the bovine STAT5A gene. A 281-bp gene fragment, from nt 12525 to nt 12806 (GenBank AJ 237937), was amplified with PCR, denatured and subjected to polyacrylamide gel electrophoresis to detect PCR-HD polymorphism. Three genotypes and two alleles were identified. DNA samples derived from homozygotes AA and BB were sequenced. A trinucleotide CCT deletion was found in the variant B of the STAT5A gene at position 12549. In a group of 72 beef bulls of various breeds and 49 Friesian bulls genotyped by PCR-HD mostly the AA genotype was found (from 83 to 61% depending on breed). The frequency of allele A varied between 0.91 and 0.77. Animals of genotype BB were found in Charolaise and Limousine breeds only.

Animals↗

[Deletion polymorphism of the angiotensin I-converting enzyme gene associates with increased risk for ischemic heart diseases in the Japanese].

The Angiotensin I-converting enzyme (ACE) is a key component of the renin-angiotensin system thought to be important in the pathogenesis of hypertension and cardiovascular diseases. Previous studies showed that deletion polymorphism in the ACE gene might be a risk factor for myocardial infarction in the Caucasian population. However, this finding has not yet been reported in the Japanese population. In this study, a 287 base pair (bp) insertion/deletion polymorphism in intron 16 of the ACE gene was examined by polymerase chain reaction (PCR) in a cross-sectional study of 35 healthy subjects and 85 patients with ischemic heart diseases (IHD) (32 angina pectoris, 53 myocardial infarction). Polymorphism of the ACE gene was characterized by three genotypes; two deletion alleles (genotype DD), two insertion allele (genotype II) and heterozygotes alleles (genotype ID). No differences could be detected among the three genotypes for total cholesterol, high-density lipoprotein cholesterol, blood pressure and body mass index. The serum ACE activities in each II, ID and DD genotype were 10.1 +/- 2.1 microU/ml, 13 +/- 3.2 microU/ml, 14.2 +/- 5.4 microU/ml, respectively. In the population study the genotype DD was significantly associated with IHD when compared with the other two genotypes (ID and II). The frequency of deletion allele was higher (0.61) in the IHD group than in the normals (0.39) (chi 2 = 7.8, p < 0.01). These frequencies were not varied whether they had classic risk factors or not. Furthermore, coronary multivessel impairment was significantly associated with the deletion allele than with the insertion allele (chi 2 = 11.7, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

A PD-1 polymorphism is associated with disease progression in multiple sclerosis.

T cells are considered to play a pivotal role in orchestrating the self-reactive immune responses in multiple sclerosis (MS). Programmed death 1 (PD-1) is a member of the B7/CD28 superfamily of costimulatory molecules exerting inhibitory functions on T cells. Recently, an intronic 7146G/A polymorphism within the PD-1 gene was described and suggested to be associated with autoimmunity. We investigated whether this genetic polymorphism is a genetic modifier for risk and progression of MS. Blood samples from 939 German MS patients (mean age, 39 years; range, 13-71; 566 patients [60%] with relapsing-remitting MS, 279 (30%) with secondary, and 94 (10%) with primary progressive MS) and 272 healthy white controls were tested. Genotyping was performed by polymerase chain reaction and restriction enzyme digestion; results were confirmed by automatic sequencing. A significant association of the mutated allele with a progressive disease course was detected (44% 7146G vs 56% 7146A, chi(2) p = 0.002). Consequences of the PD-1 mutation for T-cell function were assessed ex vivo in some patients using microsphere-stimulated peripheral blood lymphocytes and purified CD4 cells. Importantly, PD-1-mediated inhibition of T-cell cytokine secretion (interferon-gamma) is impaired in patients carrying the PD-1 polymorphism. In conclusion, our data suggest that PD-1 polymorphism is a genetic modifier of the progression of MS, possibly through inducing a partial defect in PD-1-mediated inhibition of T-cell activation.

Adolescent↗

The COMT L allele modifies the association between MAOB polymorphism and PD in Taiwanese.

OBJECTIVE: Reports suggest that catechol-O-methyltransferase (COMT(L/L)) (Val(158)/Met) and monoamine oxidase B (MAOB) intron 13 genotype polymorphism is associated with PD. To understand the ethnicity-specific effects of genetic polymorphism, we performed a case-control study of the association between PD susceptibility and polymorphism of MAOB and COMT, both separately and in combination, in Taiwanese. METHODS: Two hundred twenty-four patients with PD and 197 controls, matched for age, sex, and birthplace, were recruited. MAOB and COMT polymorphism genotyping was performed by using PCR-based restriction fragment length polymorphism (RFLP) analyses. chi(2), OR, and Fisher's exact tests were used to compare differences in allelic frequencies and genotypes. RESULTS: The MAOB G genotype (G in men and G:/G in women) was associated with a 2.07-fold increased relative risk of PD. COMT polymorphism, considered alone, showed no correlation with PD risk; however, a significant synergistic enhancement was found in PD patients harboring both the COMT(L) and MAOB G genotypes. CONCLUSIONS: These results suggest that, in Taiwanese, PD risk is associated with MAOB G intron 13 polymorphism, and this association is augmented in the presence of the COMT(L) genotype, indicating an interaction of these two dopamine-metabolizing enzymes in the pathogenesis of sporadic PD. However, the relatively low frequencies of these combined genotypes in our study necessitates confirmation with a larger sample size.

Aged↗

Lipoprotein lipase gene polymorphism and lipid profile in coronary artery disease.

CONTEXT: Lipoprotein lipase (LPL) plays a central role in lipid metabolism, hydrolyzing triglyceride in chylomicrons and very-low-density lipoproteins. The PvuII polymorphic variant of LPL gene is common and might affect risk of coronary artery disease (CAD). OBJECTIVE: Our aim was to determine whether LPL- PvuII polymorphism can be considered to be an independent risk factor or a predictor for CAD in Turkish subjects. DESIGN: We used polymerase chain reaction and restriction enzyme digestion to determine the distribution of the previously described C-->T transition that causes a PvuII polymorphism in intron 6 among healthy blood donors of Turkish origin and among angiographically confirmed CAD patients with comparable ethnic backgrounds. RESULTS: For the PvuII genotypes, within the CAD group (n = 80), the +/- genotype was found in 39 individuals (48.8%), whereas 25 (31.3%) carried the +/+ genotype, and 14 (17.5%) carried the -/- genotype. Within the control group (n = 49), the -/- genotype was found in 19 individuals (38.8%), 16 (32.7%) carried the +/- genotype, and 14 (28.6%) carried the +/+ genotype. The genotype frequency distribution was significantly different (P =.049) in the CAD and control study groups. The most frequent genotype among CAD patients was +/-; this genotype was more frequent in patients than in control subjects. However, the -/- genotype was more prevalent in the control group. Lipoprotein lipase-PvuII polymorphism was found to be associated with fasting total cholesterol and low-density lipoprotein cholesterol levels. The +/+ genotype was found to have higher levels of total cholesterol and low-density lipoprotein cholesterol in both the CAD and control groups. CONCLUSION: There was a difference in the distribution of LPL-PvuII genotypes between the healthy subjects and the patients with CAD. Lipoprotein lipase-PvuII polymorphisms were not detected as independent risk factors for CAD in this study group, but had associations with lipid levels.

Amino Acid Substitution↗

Association of the endothelial nitric oxide synthase gene polymorphism with risk of coronary artery disease and myocardial infarction in middle-aged men.

Nitric oxide (NO), formed by endothelial constitutive nitric oxide synthase (eNOS) maintains endothelium-dependent vasodilatation and also mediates antithrombotic actions. The eNOS gene harbours a common polymorphism in intron 4 (4a/b), and some clinical studies have suggested an association of the rare a-allele with coronary artery disease (CAD) and myocardial infarction (MI). However, contradictory results have also been reported. We studied associations of eNOS polymorphism with CAD and MI in two prospective autopsy series comprising altogether 700 Caucasian Finnish men, who died suddenly. In ANCOVA, no significant differences in areas of atherosclerotic lesions and coronary stenosis percentages were found between men carrying the a-allele (ba+aa) compared with those homozygous for the b-allele. Subjects with the a-allele had significantly lower risk of MI (odds ratio 0.44, 95% confidence interval 0.25-0.77, P=0.004) compared with those carrying the bb genotype. Men with the a-allele also tended to have coronary thrombosis less often (odds ratio 0.43, 95% confidence interval 0.18-1.01, P=0.055). The eNOS gene 4a/b polymorphism was not associated with the extent of coronary atherosclerosis, but the a-allele of the variant seems to protect to some degree against the development of MI.

Adult↗

Association analysis of interleukin 5 receptor alpha subunit (IL5RA) polymorphisms and asthma.

The alpha subunit of interleukin 5 receptor (IL5RA) on chromosome 3p26-p24 is known to regulate the development and function of eosinophils. In an effort to discover additional polymorphism(s) in genes whose variant(s) have been implicated in asthma, we investigated the genetic polymorphisms in IL5RA to evaluate the gene as a potential candidate for a host genetic study of asthma. By direct DNA sequencing in 24 individuals, we identified 22 sequence variants within exons and flanking regions including a 1.5-kb promoter region of IL5RA; 10 common polymorphic sites were selected for genotyping in our asthma cohort (n = 587). Two haplotype blocks were identified in a Korean population. Statistical analysis revealed that one promoter SNP, c.-5993A > G, and one ins/del polymorphism in intron 3, c.-480_482insdelGTT, showed significant association with the risk of asthma development. The genetic effects of c.-5993A>G and c.-480_482insdelGTT on asthma were more apparent among atopic subjects. Our findings suggest that polymorphisms in IL5RA might be among the genetic risk factors for asthma development, especially in atopic populations. IL5RA variant/haplotype information identified in this study will provide valuable information for strategies for the control of asthma.

Adolescent↗

Toll-like receptor 4 gene C119A but not Asp299Gly polymorphism is associated with ischemic stroke among ethnic Chinese in Taiwan.

Stroke is one of the leading causes of death in the world. Most stroke patients are classified as having ischemic stroke. The causes of ischemic stroke are very diverse. Atherosclerosis resulting in cerebral or carotid arterial stenosis/occlusion plays the most important role in the occurrence of ischemic stroke. Inflammatory processes or immune responses are involved in the formation of atherosclerosis. Toll-like receptor 4 (TLR4) is a member of the toll-like receptor (TLR) family. TLRs are pattern-recognition receptors, which initiate innate immune responses after interaction with pattern-specific ligands. A polymorphism of the TLR4 gene, Asp299Gly, is associated with an increased risk for coronary heart diseases in Caucasian populations. In this study, we explored the complete coding regions of TLR4 by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), Single-strand conformation polymorphism (SSCP), and sequencing and found obvious ethnic differences. There was no Asp299Gly polymorphism among the ethnic Chinese examined in this study. We found only one polymorphism on intron 1 (A119C) among our samples. The allele frequencies of 119A were 0.0256 and 0.0022 among the patients and controls, respectively. The odds ratio of 119A of TLR4 in ischemic stroke was 11.71 (95% CI: 1.52-90.01). This polymorphism was significantly associated with ischemic stroke. These data possibly implicate TLR4 as an important genetic factor for stroke in ethnic Chinese populations despite the rarity of the Asp299Gly polymorphism.

Aged↗

The -629C>A polymorphism in the CETP gene does not explain the association of TaqIB polymorphism with risk and age of myocardial infarction in Icelandic men.

The aim of this study was to examine whether the well-established effect of the common TaqIB polymorphism in intron 1 of the gene for cholesterol ester transfer protein (CETP) on high density lipoprotein cholesterol (HDL-C) concentration and increased risk of myocardial infarction (MI), could be explained by the recently identified -629C>A functional polymorphism in the promoter. Non-fatal MI cases (388 male) and a control group of 794 healthy men were recruited from the 30 year long prospective Reykjavik Study. In the healthy men the frequency of the TaqIB B2 allele was 0.47 (95% CI: 0.44-0.50) and there was a strong allelic association with the -629A allele (D=-0.21, P<0.0001), which had a frequency of 0.52 (95% CI: 0.49-0.56). B2B2 homozygotes displayed 15% higher HDL-C levels than subjects homozygous for the B1 allele (P<0.0001). Homozygotes for the -629A allele displayed 14% higher HDL-C concentrations than subjects homozygous for the -629C allele (P<0.0001). The frequencies of the alleles associated with lower HDL-C were significantly higher in cases compared with controls, 0.59 versus 0.53 (TaqIB B1) and 0.52 versus 0.48 (-629 C) respectively (P<0.05 for both). There was a significantly higher risk for MI in B1B1 homozygotes (OR=1.44, 95% CI: 1.10-1.87, P<0.01), compared to the other genotypes combined. This was not observed for the CC homozygotes (OR=1.16, 95% CI: 0.87-1.54). In addition, homozygotes for the TaqI B2 allele experienced a first MI 2 years later than men with other genotypes, 59 versus 61 years (P<0.05). This effect was not seen for the promoter polymorphism. These results strongly confirm the role of the CETP gene and the TaqIB variant as a risk factor for MI and suggest that another functional polymorphism is yet to be discovered in the CETP gene, that will explain the effect on MI associated with TaqIB observed in this study.

Aged↗