Overall Distribution Of Genotypes Research Articles

A Hypermutable Region in the DISP2 Gene Links to Natural Selection and Late-Onset Neurocognitive Disorders in Humans.

(CCG) short tandem repeats (STRs) are predominantly enriched in genic regions, mutation hotspots for C to T truncating substitutions, and involved in various neurological and neurodevelopmental disorders. However, intact blocks of this class of STRs are widely overlooked with respect to their link with natural selection. The human neuron-specific gene, DISP2 (dispatched RND transporter family member 2), contains a (CCG) repeat in its 5' untranslated region. Here, we sequenced this STR in a sample of 448 Iranian individuals, consisting of late-onset neurocognitive disorder (NCD) (N = 203) and controls (N = 245). We found that the region spanning the (CCG) repeat was highly mutated, resulting in several flanking (CCG) residues. However, an 8-repeat of the (CCG) repeat was predominantly abundant (frequency = 0.92) across the two groups. While the overall distribution of genotypes was not different between the two groups (p > 0.05), we detected four genotypes in the NCD group only (2% of the NCD genotypes, Mid-p = 0.02), consisting of extreme short alleles, 5- and 6-repeats, that were not detected in the control group. The patients harboring those genotypes received the diagnoses of probable Alzheimer's disease and vascular dementia. We also found six genotypes in the control group only (2.5% of the control genotypes, Mid-p = 0.01) that consisted of the 8-repeat and extreme long alleles, 9- and 10-repeats, of which the 10-repeat was not detected in the NCD group. The (CCG) repeat specifically expanded in primates. In conclusion, we report an indication of natural selection at a novel hypermutable region in the human genome and divergent alleles and genotypes in late-onset NhCDs and controls. These findings reinforce the hypothesis that a collection of rare alleles and genotypes in a number of genes may unambiguously contribute to the cognition impairment component of late-onset NCDs.

Haplotype-based, case-control study of the receptor (calcitonin) activity-modifying protein (RAMP) 1 gene in essential hypertension.

The adrenomedullin receptor is a complex molecule that comprises the calcitonin-receptor-like receptor (CRLR) and the receptor-activity-modifying protein (RAMP). RAMP1 is a vasodilation factor, and RAMP1-deficient mice (RAMP1(-/-)) exhibit inflammatory responses with a significant transient increase in serum calcitonin-gene-related peptide levels and proinflammatory cytokines when compared with RAMP1(+/+) mice. The purpose of the present study was to investigate the relationships between essential hypertension (EH) and RAMP1 gene single-nucleotide polymorphisms (SNPs) or haplotypes in a Japanese population via a case-control study. Based on a database search of the National Center of Biotechnology Information website and the HapMap project, we chose six RAMP1 gene SNPs and performed an association study involving 263 patients with EH and 267 age-matched normotensive (NT) subjects. There was no significant difference between the EH and NT groups with regard to overall distribution of genotypes or SNP alleles. However, the haplotype-based case-control analysis revealed that there was a significant difference between the EH and NT groups with regard to overall distribution of the allele combinations at three SNPs-rs3754701-rs3769048-rs10199956-(P=0.002). The T-A-T haplotype was significantly more common in the EH group (10.3%) than in the NT control group (6.1%) (P=0.047). These results suggested that this T-A-T RAMP1 gene haplotype might have utility as a genetic marker for EH and that the RAMP1 gene or a neighbouring gene may be associated with increased susceptibility to EH.

Association of thromboxane A2 receptor gene polymorphisms with cerebral infarction in a Chinese population

Platelet aggregation is crucial for the development of cerebral infarction (CI) and it is markedly increased due to the binding of thromboxane A2 (TXA2) to its receptor (TXA2R). Therefore, TXA2R plays a central role in the pathogenesis of atherosclerosis and thrombosis. This study aimed to investigate the relationship between human TXA2R gene single nucleotide polymorphisms (SNPs) and non-cardiogenic CI in a Chinese cohort. Two SNPs, rs768963 and rs4523, located in the regulatory and coding regions of TXA2R gene, respectively, were examined in DNA samples from 407 Chinese patients with CI and 270 controls. 407 CI was categorized into subtypes using Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. There was no significant association between rs4523 variants and CI. However, there was a significant difference in the overall distribution of genotypes and dominant/recessive models of rs768963 between CI and control groups. In addition, multiple logistic regression analysis revealed that the C allele of rs768963 was significantly associated with total CI (P = 0.023), large artery atherosclerosis subtype (P = 0.009), small artery occlusion subtype (P = 0.044) after adjusting for confounding factors (odds ratio = 1.533, 1.918 and 1.573, respectively). We conclude that TXA2R rs768963 polymorphism is associated with CI in a Chinese population.

Vitamin D receptor gene polymorphisms and bone mass indices in post-menarchal Indian adolescent girls

To study the association between vitamin D receptor (VDR) gene polymorphisms and bone mass indices in adolescent girls, a cross-sectional study was conducted in 120 post-menarchal girls aged 15-18years in Pune city, India. Serum levels of ionised calcium, inorganic phosphorous, parathyroid hormone and 25-hydroxy vitamin-D were measured. Bone mineral content (BMC), bone area (BA) and bone mineral density (BMD) were measured at total body (TB), lumbar spine (LS) and left femoral neck (FN) using dual energy X-ray absorptiometry. Polymorphisms of the VDR gene at the Fok1 and Bsm1 loci were detected using SYBR Green quantitative polymerase chain reaction. The overall distribution of genotypes at the Bsm1 locus in this study was 33.3% Bb, 29.2% bb and 37.5% BB while that for the Fok1 locus was 44.2% Ff, 7.5% ff and 48.3% FF. There were no significant differences in the blood parameters when classified according to Bsm1 or Fok1 genotypes. Subjects with BB genotype have significantly higher mean TBBMC, TBBA, TBBMD and LSBMD than Bb and bb (p<0.05) and showed a tendency for association with LSBMC and LSBA (p<0.1). Subjects with Ff genotype showed a tendency for association with left FNBMC and FNBA (p<0.1). Bsm1 genotype did not show an association with FN bone indices whereas Fok1 genotype did not show association with TB or LS bone indices. In conclusion, the present study demonstrates VDR gene polymorphism, defined by Bsm1 genotype, has an influence on total body and lumbar spine bone mass indices in post-menarchal Indian girls.

PP004. Study of the methylenetetrahydrofolate reductase and the reduced-folate carrier-1 gene polymorphism in healthy and severe pre-eclamptic patients

One-carbon cycle is involved in two essential physiological processes: The synthesis of purins and pyrimidines required for DNA synthesis and repair. The other is the methylation with the methionine cycle. These one-carbon groups are served by the tetrahydrofolate and the S-adenosylmethionine. Deficiencies of the folate, or other abnormalities within the methionine pathway lead to elevated homocysteine levels. These disorders have been implicated in placental diseases. Earlier studies have shown that homocysteine levels are elevated by patients with severe pre-eclampsia than by healthy pregnant normotensive women. Methylenetetrahydrofolate reductase (MTHFR) gene C677T missense mutation has a high frequency by patients with HELLP syndrome and connected with elevated serum homocysteine levels. The reduced-folate carrier (RFC-1) facilitates the internalization of 5-methyltetrahydrofolate from the blood into peripheral cells. The mutation G80A this gene leads to higher plasma folate. Our aim was to identify the polymorphism of these two genes in samples of severe pre-eclamptic patients and healthy controls. Blood samples were collected from healthy pregnant normotensive women (n=82) and women with pre-eclampsia (n=75). DNA was isolated and quantitative real-time PCR method combined with melting curve analysis was performed for the detection of the two polymorphisms. Statistical analysis was performed with the STATISTICA software package. The frequency of the A allele in the RFC-1 gene was 46.57% by healthy pregnant and 41% by severe pre-eclamptic patients. The overall distribution of genotypes was not significantly different between the control and pre-eclamptic groups (p=0.58). In the study groups by the MTHFR gene the frequency of the T was 32% in pre-eclamptics, and 35.92% in controls. Similarly the overall distribution of genotypes was not significantly different between the two study groups (p=0.15). In hypertensive disorders of the pregnancy the one-carbon cycle is disturbed. We studied single nucleotide mutations in the genes of two enzymes involved in the cycle. We determined the allele and genotype frequencies in healthy control and pre-eclamptic patients and found no significant differences. Further examinations of other genetical compounds can help to understand the elevated homocysteine levels in pre-eclampsia.

Haplotype-Based Case-Control Study on Human Apurinic/Apyrimidinic Endonuclease 1/Redox Effector Factor-1 Gene and Essential Hypertension

Oxidative DNA damage is involved in the pathophysiology of essential hypertension (EH), which is a multifactorial disorder. Apurinic/apyrimidinic endonuclease 1/redox effector factor-1 (APE1/REF-1) is an essential endonuclease in the base excision repair pathway of oxidatively damaged DNA, in addition to having reducing properties that promote the binding of redox-sensitive transcription factors. Blood pressure in APE1/REF-1-knockout mice is reported to be significantly higher than in wild-type mice. The aim of this study was to investigate the relationship between EH and the human APE1/REF-1 gene through a haplotype-based case-control study using single-nucleotide polymorphisms (SNPs). We selected five SNPs in the human APE1/REF-1 gene (rs1760944, rs3136814, rs17111967, rs3136817, and rs1130409), and performed case-control studies in 265 EH patients and 266 age-matched normotensive (NT) subjects. rs17111967 was found to show nonheterogeneity among Japanese subjects. There were no significant differences in the overall distribution of genotypes or alleles for each SNP between EH and NT groups. In the overall distribution of the haplotype-based case-control study constructed based on rs1760944, rs3136817, and rs1130409, the frequency of the G-T-T haplotype was significantly higher in the EH group than in the NT group (2.1% vs. 0.0%, P = 0.001). Multiple logistic regression analysis also revealed significant differences for the G-T-T haplotype, even after adjustment for confounding factors (OR = 8.600, 95% CI: 1.073-68.951, P = 0.043). Based on the present results, the G-T-T haplotype appears to be a genetic marker of EH, and the APE1/REF-1 gene appears to be a susceptibility gene for EH.

Case-control Study of the Role of the Gitelman's Syndrome Gene in Essential Hypertension

Gitelman's syndrome is an inherited tubular disorder characterized by sodium wasting, low blood pressure, secondary hyperaldosteronism, metabolic alkalosis, hypokalemia, hypomagnesemia of renal origin, and hypocalciuria. The majority of patients with this syndrome carry inactivating mutations in the SLC12A3 gene encoding the thiazide-sensitive Na (+)-Cl (-) cotransporter (NCC) located in the distal convoluted tubule, which is involved in renal sodium reabsorption. This suggests that the SLC12A3 gene is involved in mediation of blood pressure levels. The aim of the present study was to investigate relationships between single nucleotide polymorphisms (SNPs) in the human SLC12A3 gene and essential hypertension (EH) in Japanese. We selected 3 SNPs in the human SLC12A3 gene (T180K, A569V, L849H), and performed a case-control study of 315 EH patients and 305 normotensive (NT) individuals. There was no significant difference in overall distribution of genotypes or alleles of any of the SNPs between the EH and NT groups. We conclude that the causal gene of Gitelman's syndrome is not involved in determining blood pressure levels.

Haplotype-Based Case-Control Study of Estrogen Receptor α (ESR1) Gene and Pregnancy-Induced Hypertension

Hypotheses about pregnancy-induced hypertension (PIH) have been proposed to explain the vascular damage that characterizes this disease. Reports indicate that estrogens and estrogen receptors play important physiological roles in cardiovascular diseases. There have been studies examining the association between coronary artery disease and the estrogen receptor alpha (ESR1) gene. The aim of the present work was to assess the association between PIH and single-nucleotide polymorphisms (SNPs) in the human ESR1 gene, by conducting a haplotype-based case-control study. Based on a database search at the web site of the National Center of Biotechnology Information, we chose five SNPs in the human ESR1 gene, and performed an association study using 95 PIH patients and 200 age-matched non-PIH subjects. The frequency of rs2881766 genotypes and alleles differed significantly between the two groups. There was no significant difference in overall distribution of genotypes or alleles of the other four SNPs. The T allele of rs2881766 was significantly more prevalent in the PIH group than in the non-PIH group. Haplotype-based case-control analysis revealed that there was a significant difference in overall distribution of the combinations rs2881766-rs1643821-rs988328 and rs2881766-rs1643821 between the PIH group and the non-PIH group (all or body mass index [BMI]-matched). One susceptibility haplotype for PIH and two resistance haplotypes for PIH were revealed by comparison between the PIH group and the non-PIH (BMI-matched) control group. In conclusion, the T allele of rs2881766 could be a useful genetic marker of PIH. The G-A-T haplotype of rs2881766-rs1643821-rs988328 and the G-A haplotype of rs2881766-rs1643821 appear to be resistance markers of PIH.

Association of aromatase and estrogen receptor gene polymorphisms with hip fractures

Two polymorphisms of the aromatase and estrogen receptor genes appeared to interact to influence the risk of hip fractures in women. Allelic variants of the aromatase gene have been associated with bone mineral density and vertebral fractures. Our objective was to analyze the relationship between two polymorphisms of the aromatase and estrogen receptor genes and hip fractures. We studied 498 women with hip fractures and 356 controls. A C/G polymorphism of the aromatase gene and a T/C polymorphism of the estrogen receptor alpha gene were analyzed using Taqman assays. Aromatase gene expression was determined in 43 femoral neck samples by real-time RT-PCR. There were no significant differences in the overall distribution of genotypes between the fracture and control groups. However, among women with a TT genotype of the estrogen receptor, the CC aromatase genotype was more frequent in women with fractures than in controls (39 vs. 23%, p = 0.009). Thus, women homozygous for T alleles of estrogen receptor and C alleles of aromatase were at increased risk of fracture (odds ratio 2.0; 95% confidence interval 1.2-3.4). The aromatase polymorphism was associated with RNA levels in bone tissue, which were three times lower in samples with a CC genotype (p = 0.009). These common polymorphisms of the aromatase and estrogen receptor genes appear to interact, influencing the risk of hip fractures in women.

Association between prostaglandin E2 receptor gene and essential hypertension

Background Essential hypertension (EH) is a complex multifactorial polygenic disorder that is thought to result from an interaction between an individual's genetic makeup and various environmental factors. In the kidney, prostaglandins (PGs) are important mediators of vascular tone and salt and water homeostasis, and are involved in the mediation and/or modulation of hormonal action. In previous studies, mice deficient in the prostaglandin E2 (PGE 2) EP2 receptor had resting systolic blood pressure (BP) that was significantly lower than that of wild-type controls. The BP of those mice increased when they were put on a high-salt diet, suggesting that the EP2 receptor is involved in sodium handling by the kidney. In the present study, we investigated the association between EH and nucleotide polymorphisms in the gene encoding the prostaglandin E2 receptor subtype EP2 (PTGER2). Methods We selected three single-nucleotide polymorphisms (SNP) in the human PTGER2 gene (rs1254601, rs2075797, and rs17197), and we performed a genetic association study of 266 EH patients and 253 age-matched normotensive (NT) controls. Results There was no significant difference in overall distribution of genotypes or alleles of any of the SNP between the EH and NT groups. However, among men, the A/A type of the SNP rs17197 (rs17197, A/G in 3′UTR) was significantly more frequent in EH subjects than in NT subjects ( P=0.041). Conclusion The present findings suggest that rs17197 is useful as a genetic marker of EH in men.

A Novel Variable Number of Tandem Repeat of the Natriuretic Peptide Precursor B gene's 5'-Flanking Region is Associated with Essential Hypertension among Japanese Females

Brain natriuretic peptide (BNP) acts primarily as a cardiac hormone; it is produced by the ventricle and has both vasodilatory and natriuretic actions. Therefore, the BNP gene is thought to be a candidate gene for essential hypertension (EH). The present study identified variants in the 5'-flanking region of natriuretic peptide precursor B (NPPB) gene and assessed the relationship between gene variants and EH. The polymerase chain reaction-single strand conformation polymorphism method and nucleotide sequencing were used to identify variants. A novel variable number of tandem repeat (VNTR) polymorphism in the 5'-flanking region (-1241 nucleotides from the major transcriptional initiation site) was discovered. This VNTR polymorphism is a tandem repeat of the 4-nucleotide sequence TTTC. There were 8 alleles, ranging from 9-repeat to 19-repeat. An association study was done involving 317 EH patients and 262 age-matched normotensive (NT) subjects. The 11-repeat allele was the most frequent (88.2%); the 16-repeat allele was the second most frequent (10.5%) in the NT group. The observed and expected genotypes were in agreement with the predicted Hardy-Weinberg equilibrium values (P=0.972). Among females, the overall distribution of genotypes was significantly different between the EH and NT groups (p=0.039). The frequency of the 16-repeat allele was significantly lower in the female EH group (6.5%) than in the female NT group (12.2%, p=0.046). The 16-repeat allele of the VNTR in the 5'-flanking region of NPPB appears to be a useful genetic marker of EH in females.

Meta-analysis of association of deletion allele of angiotensin-converting enzyme gene with coronary heart disease in China

To qualitatively and quantitatively assess the evidence regarding the relation of ACE I/D polymorphism to coronary heart disease (CHD) risk. Medline (January 1994 to February 2005) and China Hospital Knowledge Databases (January 1994 to May 2005) were retrieved for all publications relating to case-control studies reporting a link between CHD risk factors and the ACE I/D polymorphism. All 16 association studies were identified and a meta-analysis was conducted by using the RevMan 4.2 estimate for odds ratio (OR) to determine whether the DD genotype might predict the outcome in CHD. Sixteen out of 48 identified studies reporting data on 1345 CHD patients and 1286 matched controls fulfilled these inclusion criteria. The overall distribution of genotypes in the control subjects was 35.88% II, 40.86% ID, and 23.26% DD. The odds ratio for CHD for DD versus ID/II genotypes across all studies was 2.56 [95% CI, 2.09 - 3.13]. The relative CHD risk appeared to be increased with the D allele (chi(Trend)(2) = 97.12, P < 0.01). ACE gene I/D polymorphism should be associated with susceptivity of coronary heart disease in China. The CHD risk is increased significantly in individuals with DD genotypes. The ACE D allele should be a risk factor for CHD.

Relationship between the Thromboxane A2 Receptor Gene and Susceptibility to Cerebral Infarction

The risk of cerebral infarction (CI) in an individual is dependent on the interplay between genetic risk factors and environmental influences. Binding of thromboxane A2 (TXA2) to its receptor (TP) modulates thrombosis/hemostasis and plays a significant role in the pathogenesis of CI. The aim of the present study was to investigate the relationship between human TP gene single nucleotide polymorphisms (SNPs) and haplotypes and CI in a Japanese population. A genetic association study was performed in 194 CI patients and 365 non-CI subjects by specifically characterizing 6 SNPs in the human TP gene (rs2271875, rs768963, rs2238634, rs11085026, rs4523 and rs4806942). Analysis demonstrated that there were significant differences in the overall distribution of genotypes and dominant or recessive models of rs2271875 and rs768963 between the CI and the non-CI groups. Multiple logistic regression analysis revealed that the C allele of rs768963 was significantly associated with CI (p = 0.029), even after adjusting for confounding factors (odds ratio: 2.41). Further, the C-T-C haplotype of rs768963-rs2238634-rs4806942 was significantly more frequent in the CI group (23.0%) than in the non-CI group (17.7%). These results suggest that specific SNPs and haplotypes may have utility as genetic markers for the risk of CI and that TP or a neighboring gene is associated with the increased susceptibility to CI.

Prevalence of Hepatitis C Virus Genotypes in a Spanish Liver Transplant Unit

Introduction Among the at least six major identified genotypes of HCV, genotype 1b, the one associated with a poorer prognosis, is the most prevalent in Spain. We aimed to compare the distribution of hepatitis C virus genotypes in our liver transplant unit with that of the other HCV patients at our institution ( n = 413) in order to assess whether genotype 1b is more prevalent among patients with more severe liver disease. Patients and methods One hundred eight patients of mean age 56 years included 81 (75%) OLT recipients and 27 (25%) with HCV cirrhosis. Determination of HCV genotypes was made with the Inno-LiPA HCV III. Results The overall distribution of genotypes was: 1b, 93 patients (86.1%); 1a; eight patients (7.4%); 3, four patients (3.7%); 4; two patients (1.9%), and 2; one patient (0.9%). The distribution was similar among patients with cirrhosis and OLT. Genotype 1b patients were older. Eleven (78.6%) of 14 patients with hepatocellular carcinoma had genotype 1b. In the control group the distribution was: 1b, 287 patients (69.5%); 1a, 54 patients (12.1%); 3, 41 patients (9.9%); 4, 20 patients (4.8%), and genotype 2, 11 patients (2.7%). This differences in the distribution of genotypes between our population and the control group was statistically significant ( P < .001). Conclusions Genotype 1b, the most prevalent genotype in our liver transplant unit, included older patients in whom hepatocellular carcinoma was common, perhaps due to their higher prevalence of cirrhosis.

Association study of calcitonin-receptor-like receptor gene in essential hypertension

Plasma adrenomedullin (ADM) concentrations increase in patients with hypertension, renal failure, heart failure, essential pulmonary hypertension, myocardial infarction, endotoxin shock, and many other conditions. The ADM receptor is a complex molecule that consists of calcitonin-receptor-like receptor (CRLR) and receptor activity-modifying protein 2 (RAMP2). Because CRLR determines the binding specificity of ADM, the CRLR gene is thought to be a susceptibility gene of hypertension. However, studies have not yet defined the relationship between the CRLR gene and hypertension. The aim of the present study was to investigate relationships between single-nucleotide polymorphisms (SNP) in the human CRLR gene and essential hypertension (EH) in a Japanese population. We selected four SNP in the human CRLR gene (rs3771073, rs696574, rs698590, and rs1528233), and we performed a genetic association study in 209 EH patients and 216 age-matched normotensive (NT) individuals. There was no significant difference in overall distribution of genotypes or alleles of any of the SNP between the EH and NT groups. However, among women, the T allele of the SNP rs696574 (C --> T, in intron 6) was significantly more frequent in EH subjects than in NT subjects (P = .032). Our findings suggest that rs696574 can be used as a genetic marker of EH in women.

Association of a functional single‐nucleotide polymorphism of PTPN22, encoding lymphoid protein phosphatase, with rheumatoid arthritis and systemic lupus erythematosus

To assess the possible association between the PTPN22 gene 1858C-->T polymorphism and the predisposition and clinical expression of 2 systemic autoimmune diseases, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Our study population consisted of 826 RA patients, 338 SLE patients, and 1,036 healthy subjects. All subjects were of Spanish Caucasian origin. Genotyping of the PTPN22 gene 1858C-->T polymorphism was performed by real-time polymerase chain reaction technology, using the TaqMan 5'-allele discrimination assay. The overall distribution of genotypes in the RA patients was significantly different from that in the controls (P = 0.005, by chi-square test with 2 x 3 contingency tables). We observed a statistically significant difference in the distribution of the PTPN22 1858T allele between healthy subjects (7.4%), and RA patients (10.4%) (P = 0.001, odds ratio [OR] 1.45 [95% confidence interval (95% CI) 1.15-1.83]). In addition, PTPN22 1858 C/T and T/T genotypes were present at a significantly higher frequency in SLE patients than in controls (P = 0.02, OR 1.55 [95% CI 1.05-2.29]). Differences were also observed when allele frequencies were compared, with the PTPN22 1858T allele being present at a higher frequency among SLE patients (P = 0.03, OR 1.45 [95% CI 1.01-2.09]). These results suggest that the PTPN22 1858T allele may confer differential susceptibility to RA and SLE in the Spanish population.

An association study in essential hypertension using functional polymorphisms in lymphotoxin-α gene

Lymphotoxin-alpha (LTA), a member of the tumor necrosis factor family, is a cytokine produced by lymphocytes. The substance LTA mediates a wide variety of inflammatory, immunostimulatory, and antiviral responses. In 2002, LTA was identified as a major risk factor for myocardial infarction (MI) in Japanese individuals, in a large-scale case-control study using 92,788 gene-based single-nucleotide polymorphism (SNP) markers in the whole human genome. Essential hypertension (EH) is thought to be a multifactorial disorder involved in endothelial dysfunction and atherosclerosis. Although hypertension is one of the greatest risk factors for MI, there have been no reports estimating the association between EH and LTA. The aim of the present study was to evaluate the association between EH and the LTA gene. In the present study, we assessed the association between EH and SNP and haplotypes of the LTA gene in a case-control study of 202 EH patients and 217 age-matched normotensive control subjects. The overall distribution of genotypes for each SNP did not significantly differ between the two groups. Furthermore, the haplotype analysis revealed no association between the EH and normotensive groups. Polymorphisms of the LTA gene were not associated with EH. This finding suggests differences in genetic backgrounds between EH and MI.

Intrauterine cytomegalovirus infection and glycoprotein B genotypes.

Cytomegalovirus (CMV) strains display polymorphisms for the gene encoding glycoprotein B (gB; gpUL55). Recent data suggest that the gB genotype may influence the outcome of acquired CMV infections. To determine whether the gB genotype also contributes to the outcome of intrauterine infection, CMV strains were studied from 56 infants with culture-confirmed intrauterine CMV infections who were born in Iowa or Texas. CMV gB genotypes were compared with the neonatal clinical features and neurodevelopmental outcomes. Fifty-three strains (95%) could be assigned a gB genotype. The overall distribution of genotypes was as follows: type 1, 50%; type 2, 18%; type 3, 23%; and type 4, 4%. Strains with the gB 3 genotype were more common among the Iowa infants (P=.082). The gB 3 genotype was more common among infants with asymptomatic infections (P=.004), but geographic location and ascertainment biases may have accounted for these differences. The gB genotypes did not correlate with the neurodevelopmental outcome of intrauterine infection.

Involvement of Fcgamma receptor IIIA genotypes in susceptibility to rheumatoid arthritis.

To investigate a possible association of Fcgamma receptor IIIA (FcgammaRIIIA) gene polymorphism at position 158 with susceptibility to, and the outcome of, rheumatoid arthritis (RA). One hundred seventeen RA patients and 142 unrelated healthy control subjects from the same geographic area were studied. Genotyping for FcgammaRIIIA-158V/F was performed by a method based on polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis using amplification-created restriction sites. HLA-DRB1 typing by PCR-sequence-specific oligonucleotide hybridization (reverse hybridization) was also performed. Allele and genotype distributions in healthy controls were similar to those reported in other populations. The overall distribution of genotypes in the patients was significantly different from that in the controls (P = 0.023, by chi-square test from 3 x 2 contingency table). An overrepresentation of the FcgammaRIIIA-158FF genotype in the patients was observed (for 158FF versus non-158FF P = 0.01, odds ratio [OR] 1.98, 95% confidence interval [95% CI] 1.16-3.4). However, the FcgammaRIIIA-158VF genotype was increased in controls (for 158VF versus non-158VF P = 0.021, OR 0.54, 95% CI 0.32-0.92). No associations were found with any of a series of clinical parameters. Analysis of FcgammaRIIIA-158FF along with shared epitope showed that the presence of both factors increased the susceptibility to RA (P = 0.0009, OR 3.6, 95% CI 1.63-8.01); however, they probably do not interact to produce this effect. These results indicate that the FcgammaRIIIA-158 genotypes confer differential susceptibility to RA in our study population. Further studies to elucidate the role of this polymorphism in the pathogenesis of RA and other autoimmune diseases are warranted.

A meta-analysis of the association of the deletion allele of the angiotensin-converting enzyme gene with myocardial infarction.

The ACE gene is characterized by a polymorphism based on the presence (insertion [I]) or absence (deletion [D]) within intron 16 of a 287-basepair alu repeat sequence, resulting in three genotypes (DD and II homozygotes and ID heterozygotes). In 1992, the DD genotype was reported to be associated with an increased risk of myocardial infarction (MI). Subsequent studies have produced conflicting findings. To further evaluate the association of the ACE I/D genotype with MI risk, we carried out a meta-analysis of all the published studies. In total, 15 studies containing 3394 MI cases and 5479 control subjects were analyzed. The overall distribution of genotypes in the control subjects was 22.7% II, 49.0% ID, and 28.3% DD. The mean odds ratio for MI for DD versus ID/II genotypes across all studies was 1.26 (95% CI, 1.15, 1.39; P < .0001). Pairwise odds ratios were 1.36 (95% CI, 1.19, 1.55) for DD and II, 1.24 (95% CI, 1.11, 1.38) for DD and ID, and 1.09 (95% CI, 0.96, 1.23) for ID and II. The relative risk appeared to be increased in Japanese populations (2.55; 95% CI, 1.75, 3.70). Within the limitations of the available data, the meta-analysis therefore supports an association of the ACE D allele with MI risk and strengthens the justification for further evaluation in appropriately powered studies.