Investigation of Serum Angiotensin-Converting Enzyme (ACE) Concentration and ACE Gene Polymorphism in Patients With SARS-CoV-2 Pneumonia Admitted to the Emergency Department

Background This study seeks to investigate the distribution of the angiotensin-converting enzyme (ACE) gene polymorphism and serum levels in patients with viral pneumonia and predict which polymorphism will lead to severe progression of the disease. Methodology The serum ACE levels and ACE gene polymorphisms were successfully evaluated with respect to subsequent viral pneumonia using records of 100 patients with viral pneumonia and 100 healthy controls. Results ACE serum concentration was statistically significantly elevated. ACE serum concentration with a cut-off value of ≥5,256.05 pg/mL had 85.3% sensitivity and 83.2% selectivity. In addition, patients with ACE genotype D/D were 0.08 times more likely to manifest severe lung involvement than those with I/I, and patients with the I/D genotype were 0.02 times more likely than their counterparts with I/I. The computed tomography findings of the patients revealed that ACE serum concentration was significantly effective in discriminating between mild and moderate-to-severe lung involvement. No significant difference was observed between the blood parameters and ACE genotype distributions. Conclusions I/D polymorphism likely affects the expression of the ACE gene and/or the function of the angiotensin I converting enzyme. The D/D genotype is associated with vessel wall thickness and higher blood pressure. Strong evidence was found between D/D and I/D genotypes in the patient cohort concerning genotypes and ACE serum concentration. Further analysis showed that ACE serum levels were more elevated in the D/D genotype compared to the I/D genotype in the patient cohort.

Serum INHB Levels and ACE Gene I/D Polymorphism with Increased Risk for Unexplained Infertility

ACE has a significant role in the angiogenesis of ovarian endothelium and the resumption of meiosis and folicular growth. However, there is no any study concerning ACE polymorphism and UI. The main aim of this study is that both identify ACE polymorphism and measure the serum ACE, AMH and INHB levels in UI patients and controls in Turkish population. 47 UI patients and 41 controls were involved in this study. To determine the ACE polymorphisms, DNA isolation and PCR were performed. Then, serum ACE, AMH and INHB levels were measured spectrophotometrically. Patients with UI had significantly higher serum INHB levels compared with controls (p < 0.05). Serum ACE levels were decreased, compared to controls, however the decrease were not significant. Serum AMH levels did not significantly differ from controls. When the relationship were analyzed between ACE I/D polymorphism and infertility risk, and ID genotype were chosen as reference, it was found to be 2.33 times more risk of UI that the women have DD genotype (DD vs. ID: odds ratio = 2.33, 95% confidence interval (0,88-6,19); p = 0,086). This finding indicates that DD genotype may be high risk for UI. Further studies are warranted to confirm this finding, especially with a larger population.

Role of CLU, PICALM, and TNK1 Genotypes in Aging With and Without Alzheimer's Disease

Healthy and impaired cognitive aging may be associated to different prevalences of single-nucleotide polymorphisms (SNPs). In a multicenter case-control association study, we studied the SNPs rs11136000 (clusterin, CLU), rs541458 (phosphatidylinositol binding clatrin assembly protein, PICALM), and rs1554948 (transcription factor A, and tyrosine kinase, non-receptor, 1, TNK1) according to the three age groups 50-65 years (group 1), 66-80 years (group 2), and 80+ years (group 3) in 569 older subjects without cognitive impairment (NoCI) and 520 Alzheimer's disease (AD) patients. In NoCI subjects, a regression analysis suggested a relationship between age and TNK1 genotypes, with the TNK1-A/A genotype frequency that increased with higher age, and resulting in a different distribution of the TNK1-A allele. In AD patients, a regression analysis suggested a relationship between age and PICALM genotypes and TNK1 genotypes, with the PICALM-T/C and TNK1-A/A genotype frequencies that decreased with increasing age. A resulting difference in the distribution of PICALM-C allele and TNK1-A allele was also observed. The TNK1-A allele was overrepresented in NoCI subjects than in AD patients in age groups 2 and 3. These results confirmed after adjustment for apolipoprotein E polymorphism, which suggested a different role of PICALM and TNK1 in healthy and impaired cognitive aging. More studies, however, are needed to confirm the observed associations.

Genetic markers: Potential candidates for cardiovascular disease

The effective prevention of cardiovascular disease depends upon the ability to recognize the high-risk individuals at an early stage of the disease or long before the development of adverse events. Evolving technologies in the fields of proteomics, metabolomics, and genomics have played a significant role in the discovery of cardiovascular biomarkers, but so far these methods have achieved the modest success. Hence, there is a crucial need for more reliable, suitable, and lasting diagnostic and therapeutic markers to screen the disease well in time to start the clinical aid to the patients. Gene polymorphisms associated with the cardiovascular disease play a decisive role in the disease onset. Therefore, the genetic marker evaluation to classify high-risk patients from low-risk patients trends an effective approach to patient management and care. Currently, there are no genetic markers available for extensive adoption as risk factors for coronary vascular disease, yet, there are numerous promising, biologically acceptable candidates. Many of these gene biomarkers, alone or in combination, can play an essential role in the prediction of cardiovascular risk. The present review highlights some putative emerging genetic biomarkers that could facilitate more authentic and fast diagnosis of CVD. This review also briefly describes few technological approaches employed in the biomarker search.

Ramifications of Four Concurrent Thrombophilic Mutations and One Hypofibrinolytic Mutation

A kindred was examined in which the 48-year-old white female proband with three deep venous thrombosis-pulmonary emboli events had four thrombophilic and one hypofibrinolytic mutations, and in which her 14-year-old asymptomatic daughter had four thrombophilic mutations. The proband was heterozygous for the G1691A factor V Leiden, G20210A prothrombin, and platelet glycoprotein IIIa PL A1/A2 mutations, had high factor VIII (221%), and was homozygous for the 4G4G plasminogen activator inhibitor-1 gene mutation, with high plasminogen activator inhibitor activity (23.7 U/mL). Her 14-year-old daughter was homozygous for the G1691A factor V Leiden and platelet glycoprotein IIb-IIIa PL A2/A2 mutations, compound heterozygous for the C677T and A1298C methylenetetrahydrofolate reductase (MTHFR) mutations, and heterozygous for the G20210A prothrombin mutation, a combination with an estimated likelihood of 1.6 × 10-7. In 247 white healthy controls, there was no V Leiden homozygosity and no V Leiden-prothrombin gene compound heterozygosity. Heterozygosity for the V Leiden and prothrombin gene mutations was 3.2% and 4.1%, respectively. Homozygosity for the platelet glycoprotein IIb-IIIa PL A2A2, PAI-1 gene 4G4G, and C677T MTHFR mutations was 3.2%, 22.7%, and 12%, respectively. The proband will receive anticoagulation therapy for life. Beyond aspirin, avoidance of exogenous estrogens, and enoxaparin prophylaxis during pregnancy, it is not known whether the proband’s daughter should have lifelong anticoagulation therapy, or only after her first thrombotic event.

Evidence from case-control and longitudinal studies supports associations of genetic variation in APOE, CETP, and IL6 with human longevity

In this study, we investigated 102 single-nucleotide polymorphisms (SNPs) covering the common genetic variation in 16 genes recurrently regarded as candidates for human longevity: APOE; ACE; CETP; HFE; IL6; IL6R; MTHFR; TGFB1; APOA4; APOC3; SIRTs 1, 3, 6; and HSPAs 1A, 1L, 14. In a case-control study of 1,089 oldest-old (ages 92-93) and 736 middle-aged Danes, the minor allele frequency (MAF) of rs769449 (APOE) was significantly decreased in the oldest-old, while the MAF of rs9923854 (CETP) was significantly enriched. These effects were supported when investigating 1,613 oldest-old (ages 95-110) and 1,104 middle-aged Germans. rs769449 was in modest linkage equilibrium (R (2)=0.55) with rs429358 of the APOE-ε4 haplotype and adjusting for rs429358 eliminated the association of rs769449, indicating that the association likely reflects the well-known effect of rs429358. Gene-based analysis confirmed the effects of variation in APOE and CETP and furthermore pointed to HSPA14 as a longevity gene. In a longitudinal study with 11 years of follow-up on survival in the oldest-old Danes, only one SNP, rs2069827 (IL6), was borderline significantly associated with survival from age 92 (P-corrected=0.064). This advantageous effect of the minor allele was supported when investigating a Dutch longitudinal cohort (N=563) of oldest-old (age 85+). Since rs2069827 was located in a putative transcription factor binding site, quantitative RNA expression studies were conducted. However, no difference in IL6 expression was observed between rs2069827 genotype groups. In conclusion, we here support and expand the evidence suggesting that genetic variation in APOE, CETP, and IL6, and possible HSPA14, is associated with human longevity.

Lack of association between the MTHFR C677T variant and migraine with aura in an older population: could selective survival play a role?

BACKGROUND

Several studies, but not all, of primarily middle-aged or younger adults have suggested that the common MTHFR C677T variant is a genetic risk factor for migraine with aura (MA). Here, we consider whether this variant is associated with MA risk in an older non-clinical population (AGES-Reykjavik cohort).

METHODS

Participants are a sub-sample ( N  = 1976) of subjects from the Reykjavik Study (RS; mean age 50) and its continuation, AGES-RS (mean age 76). We estimated the relative odds of MA in TT versus CC carriers using multinomial logistic regression. As both MA and the TT genotype may be linked with modestly reduced longevity, we performed a simple simulation to illustrate the effect that selective survival may have had on our observed gene-disease association.

RESULTS

TT versus CC carriers were at marginally reduced odds of MA (ORTT 0.55 (0.3-1.0), P  = 0.07), significantly for women (ORTT 0.45 (0.2-0.9), P  = 0.03). Assuming the 'true' (e.g. mid-life) effect of the TT genotype is ORTT 1.26, from a recent meta-analysis, our simulation suggested that if 25-year mortality had been (hypothetically) 13% higher in MA subjects with the TT versus CC genotype, the measured effect of the TT genotype on MA would have been attenuated to non-significance (e.g. ORTT 1.00). Our observed protective effect was consistent with the most extreme selective mortality scenario, in which essentially all of the previously reported increased mortality in MA subjects was (hypothetically) found in CT or TT carriers.

CONCLUSION

The MTHFR 677TT genotype was associated with marginally reduced risk of MA in our older population. Our simulation illustrated how even modest selective survival might obscure the apparent effect of a genetic or other risk factor in older populations. We speculate that some of the heterogeneity previously observed for this particular genetic variant may be due to age range differences in the studied populations.

The Alu polymorphism of angiotensin I converting enzyme (ACE) and atherosclerosis, incident chronic diseases and mortality in an elderly Chinese population

OBJECTIVE

We examined the contribution of ACE I/D polymorphism in a large Chinese population to four year change in ankle-brachial index (ABI), development of cardiovascular diseases and mortality in a prospective study adjusting for many confounding factors.

METHOD

Data are drawn from a longitudinal study of 4000 community-living men and women aged 65 years and over, for which detailed information regarding lifestyle, chronic diseases, body mass index (BMI), ABI measurements and ACE polymorphisms were documented at baseline. During the fifth year of follow up, incident cardiovascular diseases, ABI, and mortality were documented, and related to ACE genotype adjusting for age, smoking, alcohol, dietary intake, physical activity, body mass index, and use of ACE inhibitors.

RESULTS

Women with the D/D genotype had the greatest reduction in mean ABI after adjusting for confounding factors. D/D genotype was also more common among women who developed hypertension or myocardial infarction. However D/D genotype was associated with mortality only in men.

CONCLUSION

In a Chinese elderly population, ACE polymorphism may be considered "deleterious" to longevity, the D/D genotype being associated with mortality, the atherosclerotic process, hypertension and myocardial infarction. There are gender differences in the relationship between D/D genotype and cardiovascular diseases and mortality may not be mediated by the atherosclerotic process alone.

An association analysis of Alzheimer disease candidate genes detects an ancestral risk haplotype clade in ACE and putative multilocus association between ACE, A2M, and LRRTM3

Alzheimer's disease (AD) is the most common form of progressive dementia in the elderly. It is a neurodegenerative disorder characterized by the neuropathologic findings of neurofibrillary tangles and amyloid plaques that accumulate in vulnerable brain regions. AD etiology has been studied by many groups, but since the discovery of the APOE epsilon4 allele, no further genes have been mapped conclusively to late-onset AD (LOAD). In this study, we examined genetic association with LOAD susceptibility in 738 Caucasian families (4,704 individuals) and an independent case-control dataset with 296 cases and 566 controls exploring 11 candidate genes (47 SNPs common to both samples). In addition to tests for main effects and haplotypes, the MDR-PDT was used to search for gene-gene interactions in the family data. We observed significant haplotype effects in ACE in family and case-control samples using standard and cladistic haplotype models. ACE was also part of significant 2 and 3-locus MDR-PDT joint effects models with Alpha-2-Macroglobulin (A2M), which mediates the clearance of Abeta, and Leucine-Rich Repeat Transmembrane-3 (LRRTM3), a nested gene in Alpha-3 Catenin (CTNNA3) which binds Presenilin-1. This result did not replicate in the case-control sample, and may not be a true positive. These genes are related to Abeta clearance; thus this constellation of effects might constitute an axis of susceptibility for LOAD. The consistent ACE haplotype result between independent family-based and unrelated case-control datasets is strong evidence in favor of ACE as a susceptibility locus for AD, and replicates results from several other studies in a large sample.

Lack of genetic association between the angiotensin-converting enzyme gene insertion/deletion polymorphism and longevity in a Han Chinese population

Introduction. The insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene has been reported to associate with human longevity. However, little information is available in a Han Chinese longevity population.Therefore, we investigated the association of the ACE gene insertion/ deletion polymorphism with longevity in a Han Chinese population.

Materials and methods. We compared the distribution of ACE insertion/deletion genotype and allele frequencies in two groups: a longevity group (399 subjects) aged over 90 years and a control group (302 subjects) aged less than 60 years.

Results. No difference in genotype and allele frequencies of the ACE gene insertion/deletion polymorphism was observed between the longevity group and the control group.When adjusting for gender, the difference between the longevity group and the control group was also not significant regarding the frequencies of the genotypes (male, p=0.994 and female, p=0.797) as well as allele frequencies (male, p=0.969 and female, p=0.884).

Conclusions. No association of the ACE gene insertion/deletion polymorphism with longevity was observed in our Han Chinese population.

Prevalence of the angiotensin I converting enzyme gene insertion/deletion polymorphism in a healthy Turkish population

Angiotensin converting enzyme (ACE) plays an essential role in the renin-angiotensin system. It converts angiotensin I to angiotensin II and inactivates bradykinin and tachykinins. Numerous studies have been published investigating associations of the ACE gene I/D polymorphism with various pathophysiological conditions. We examined the prevalence of the ACE I/D polymorphism in a sample of healthy volunteers from western Turkey, including 1063 healthy Turkish controls. Analysis of the ACE I/D gene polymorphisms by polymerase chain reaction found frequencies of 16.1% for the II genotype, 47.7% for the ID genotype, and 36.2% for the DD genotype. The allele frequency was 39.9% for the I alleles and 60.1% for the D allele. This study demonstrates that the allele and genotype frequency values for the Turkish population are similar to previously published frequencies for Caucasian populations.

Genetic epidemiology in aging research

Over the last two decades, aging research has expanded to include not only age-related disease models, and conversely, longevity and disease-free models, but also focuses on biological mechanisms related to the aging process. By viewing aging on multiple research frontiers, we are rapidly expanding knowledge as a whole and mapping connections between biological processes and particular age-related diseases that emerge. This is perhaps most true in the field of genetics, where variation across individuals has improved our understanding of aging mechanisms, etiology of age-related disease, and prediction of therapeutic responses. A close partnership between gerontologists, epidemiologists, and geneticists is needed to take full advantage of emerging genome information and technology and bring about a new age for biological aging research. Here we review current genetic findings for aging across both disease-specific and aging process domains. We then highlight the limitations of most work to date in terms of study design, genomic information, and trait modeling and focus on emerging technology and future directions that can partner genetic epidemiology and aging research fields to best take advantage of the rapid discoveries in each.

No Association of Factor V Leiden, Prothrombin G20210A, and MTHFR C677T Gene Polymorphisms With Kidney Allograft Survival: A Multicenter Study

BACKGROUND

It has been proposed that inherited risk factors of venous thromboembolism, such as factor V G1691A (FV-Leiden), prothrombin G20210A, and methylenetetrahydrofolate reductase (MTHFR) C677T, might be associated with poorer survival rates of transplanted kidneys. On the basis of this hypothesis, we performed a multicenter study, involving recipients of primary and repeat kidney transplants, to investigate the potential effect of these three single nucleotide polymorphisms (SNP) on graft survival.

METHODS

The study consisted of 676 first and 651 retransplant patients. Using the polymerase chain reaction-sequence specific primers method, we typed all patients for the three SNP and analyzed graft survival.

RESULTS

We could not find a statistically significant association between graft survival and factor V Leiden or MTHFR C677T genotypes. A better 3-yr graft survival was found for first transplant recipients with the genotype prothrombin 20210 G/G as compared to those with the G/A genotype (P=0.031). However, Bonferroni correction for the three SNPs investigated in this series rendered the P value insignificant (P(corrected)=0.093).

CONCLUSION

We did not find a statistically significant association of SNP factor V Leiden G1691A and MTHFR C677T with renal graft survival. Prothrombin G20210A resulted in a significant association that was not sustained after Bonferroni correction. This SNP might be an interesting candidate for future studies.

Analysis of common polymorphisms in angiotensin-converting enzyme and apolipoprotein e genes and human longevity in Colombia

BACKGROUND

Genetic analysis of human longevity may be useful for the understanding of molecular mechanisms implicated in age-related diseases. The molecular genetics of human longevity is largely unexplored in Latin American populations and other developing countries.

METHODS

To explore the possibility of an association of common polymorphisms in two candidate genes and longevity in Colombia, we analyzed two polymorphisms in apolipoprotein E (APOE) and angiotensin-converting enzyme (ACE) genes in a sample of 538 Colombian subjects (18-106 years), using previously validated PCR-based methodologies.

RESULTS

We found a significant decrease in ACE DD genotype (24 vs. 16%) between young and old subject groups (mean age: 45 vs. 77 years) (p = 0.03). The ACE DD genotype and D allele decrease was significant only in women. There were no differences for APOE polymorphism between young and old subjects.

CONCLUSIONS

Our results are compatible with the expected age-related decrease of ACE DD genotype. Future studies examining functional single nucleotide polymorphisms (SNPs) in the ACE gene and its correlation with serum ACE activity in the older subjects and their younger relatives in this sample are warranted.

Hemostasis and aging

Many changes in the vasculature, hemostasis and endothelium, including alterations of platelets, coagulation and fibrinolytic factors, occur during aging. While the increasing hypercoagulability observed with aging may account for the higher incidence of thrombotic cardiovascular disorders in the elderly, the lack of genetic protective factors against thrombosis in healthy centenarians suggests that little is yet known about the age-associated changes of hemostasis. The complex inter-relationships between inherited and acquired factors influencing the hemostatic system during aging are discussed in this review.

Sex differences in the association of apolipoprotein E and angiotensin-converting enzyme gene polymorphisms with healthy aging and longevity: a population-based study from Southern Italy

We investigated the association of sex and age with the occurrence of apolipoprotein E (apoE) and angiotensin-converting enzyme (ACE) genotypes in healthy aging and longevity in 1344 healthy individuals and 64 centenarians. As compared to participants younger than 60 years, a significant higher frequency of the apoE/epsilon2 was observed in men aged 60-90 years (p <.001) and in centenarians (p <.001). Logistic regression analysis confirmed this outcome in both participants aged 60-90 years (odds ratio [OR] = 1.897; 95% confidence interval [CI], 1.227-2.931) and centenarians (OR = 3.263; 95% CI, 1.860-5.722). A further significant association of ACE/D allele and age was observed in centenarians (OR = 2.135; 95% CI, 1.253-3.636). Heterosis was also observed at the ACE locus. No relationship between apoE and ACE polymorphism was found. These findings suggest a role of sex in the association of apoE and ACE gene polymorphisms with healthy aging and longevity.

A new PCR-SSP typing method for six single-nucleotide polymorphisms impairing the blood-clotting cascade as well as T-cell stimulation

Single-nucleotide polymorphisms (SNPs) within the genes of factor V (FV) (G1691A; exon 10), prothrombin (FII) (G20210A; 3'untranslated - region) and methylenetetrahydrofolate reductase (MTHFR) (C677T; exon 4) are associated with hypercoagulability, and systematic screening of individuals being at higher risk of thrombosis has been suggested. SNPs in the 2q33 region within the genes of CD28 (+17T/C; intron 3) and CTLA4 (-318C/T; promoter and +49A/G; exon 1) are likely to affect T-cell proliferation and antigen presentation signaling, which may lead to altered sensitivity of allograft or self-tissue recognition and affect the incidence of autoimmune diseases. We developed primers that allow specific amplification of these six SNPs at test conditions identical with those used for HLA typing with the CTS PCR-SSP reagents. One hundred ninety-six healthy German Caucasian individuals were tested for the six SNPs. The genotype frequencies for all SNPs were in Hardy-Weinberg equilibrium. There was no significant difference in the distribution of genotypes when compared to other published studies in which these SNPs were tested. The described PCR-SSP method can be used to screen large numbers of patients for these SNPs.

Candidate genes associated with ageing and life expectancy in the Jerusalem longitudinal study

In an exploratory study, 11 common polymorphisms were examined for contributing to longevity including: apolipoprotein E (apoE), methylenetetrahydrofolate reductase (MTHFR), cathepsin D (CAD), superoxide dismutase 2 (SOD2), angiotensinogen (AGT) and insulin-like growth factor 2 (IGF2), Leiden factor 7, p53 oncogene, dopamine D4 receptor (DRD4) and the serotonin transporter (SERT). Genotype and allele frequencies of these genes were compared in 224 older (75 years) Jewish Jerusalem residents of Ashkenazi ethnicity to a group of 441 younger subjects (22 years). Nominally significant results provide suggestive evidence in the Ashkenazi group that apoE, MHTFR, SOD2, IGF2 ApaI, and factor VII are risk factors for a single outcome, survival to 75. Overall, the more genetically homogenous Ashkenazi ethnic group showed evidence for association in five genes examined suggesting that future studies in this population would gainfully focus on this ethnic group.

Methylenetetrahydrofolate reductase gene A222V polymorphism and risk of ischemic stroke

The 5,10-methylenetetrahydrofolate reductase ( MTHFR ) gene 677C --> T polymorphism causes an A222V amino acid change which affects MTHFR enzyme activity and can increase homocysteine, a vascular disease risk factor. This polymorphism was examined for association with stroke. In a case-control study of 241 ischemic stroke patients and 304 controls in Hong Kong, the V allele increased in stroke [28% vs. 20%, odds ratio (OR) 1.5, p=0.003]. A lack of significance for the increase in the VV genotype (7.5% vs. 4.6%, OR 1.7, p = 0.16) may be due to its rarity in this region. V -allele carriers had more severe strokes (according to the NIH stroke scale). The association of the V allele with stroke occurred mostly in women or older subjects and was due to decreasing V allele frequency with age, as seen in other studies. This V frequency decline with age might be due to a loss of V -carrying controls from a higher risk of cancer, vascular disease, bone fracture, and kidney failure when folate is sparse. Examination of previous studies revealed that the association of VV genotype with stroke appeared stronger in Japan than elsewhere, possibly due to dietary differences. Perhaps folate supplementation for stroke prevention would particularly benefit VV individuals in such high-risk regions.

ACE gene is associated with Alzheimer's disease and atrophy of hippocampus and amygdala

Despite biological support for a role of angiotensin converting enzyme (ACE) in Alzheimer's disease (AD), studies assessing the ACE I/D polymorphism in AD are conflicting. We re-evaluated this association in the Rotterdam Study, a population-based cohort study. The mechanism of association was further explored by adjusting for vascular factors, and by analysing atrophy, white matter lesions and infarcts on MRI in non-demented individuals. Genotypes were available for 6488 participants. During average follow-up of 6 years 250 subjects developed AD. MRI data were available for 494 non-demented participants. Homozygosity for the I-allele conferred a slightly increased risk of AD compared to carrying a D-allele (RR 1.12 (95% CI 0.99-1.25)). This increase was only significant in women, and independent of vascular factors (RR 1.39 (95% CI 1.14-1.69)). Non-demented women with the II genotype had smaller hippocampal and amygdalar volumes. Vascular pathology was not significantly associated with ACE. This suggests a modest but significant increase in risk of AD and early AD pathology in women homozygous for the ACE I-allele independent of vascular factors.

A2 Alelle of GpIIIa Gene Is a Risk Factor for Stroke Caused by Large-Vessel Disease in Males

Background and Purpose— Glycoprotein IIIa (GpIIIa) is a platelet membrane receptor for fibrinogen and von Willebrand factor. It plays a key role in platelet aggregation. Previous studies in stroke patients, without analysis based on specific subtypes of stroke cause, have not shown any link between GpIIIa A1/A2 polymorphism and stroke risk. We studied the significance of the GpIIIa gene A1/A2 polymorphism in stroke patients with different stroke causes.

Methods— We genotyped 92 patients with stroke caused by large-vessel disease (LVD stroke) and 184 matched controls; 103 patients with stroke caused by small-vessel disease (SVD stroke) and 206 controls; and 182 patients with cardioembolic stroke (CE stroke) and 182 controls (TOAST criteria). The GpIIIa A1/A2 polymorphism was analyzed by polymerase chain reaction followed by restriction enzyme digestion and electrophoresis.

Results— The genotype distribution of the GpIIIa gene in patients with LVD stroke (A1/A1, 63%; A1/A2, 34.8%; A2/A2, 2.2%) differed significantly from their controls (A1A1, 79.3%; A1/A2, 20.1%; A2/A2, 0.6%). The distribution of the GpIIIa A1/A2 polymorphism in patients with SVD stroke and CE stroke was similar to that of their controls. In contrast to females with LVD stroke, we found that males with LVD stroke presented with an overrepresentation of at least 1 A2 allele of the GpIIIa gene when compared with their controls (39.7% versus 23.0%; P =0.003). Conditional logistic regression analysis showed that possession of at least 1 A2 allele of the GpIIIa gene was an independent risk factor for LVD stroke in males (OR, 2.51; 95% CI, 1.21 to 5.20).

Conclusion— A2 allele of the GpIIIa gene is an independent risk factor for LVD stroke in males.

Vascular genetic factors and human longevity

Complex inter-relationships between age-associated illnesses, such as vascular disease and Alzheimer's disease (AD), suggest that biological and genetic pathways may be worthy of examination in centenarian populations to provide insights into human longevity. This is also borne out by the involvement of lipoprotein metabolism and a number of vascular genetic risk factors. Repeated findings of a higher frequency of the apolipoprotein E (APOE) epsilon4 allele in middle-aged subjects compared with centenarians were reported. Furthermore, we have also shown how in different populations there is a significant trend in reduction of serum APOE levels from APOE epsilon2- to epsilon4-carrier as well as significant differences in serum APOE levels respect to age in epsilon4-carriers but only after adjustment for HDL cholesterol. In contrast, findings of increased prevalence of the angiotensin I converting enzyme 1 (ACE1) D allele in French centenarians have not been replicated, suggesting the possibility that regional differences may occur in ACE1(*)D frequency within Europe in centenarians, as has been recently reported for APOE epsilon2 and epsilon4 alleles. A number of studies have examined the potential role in longevity of other genes involved in vascular risk, haemostasis, and blood pressure regulation [methyltetrahydrofolatereductase (MTHFR), apolipoprotein A1 (APOA-I), apolipoprotein C3 (APOC-III), apolipoprotein A4 (APOA-IV), paraoxonase 1 (PON1), plasminogen activator inhibitor type I (PAI-1)], with contrasting results. While further studies are needed to confirm the possible role of APOE concentration as putative longevity factor, this paper provides an overview of genetic vascular factors potentially involved in human longevity.

Methylenetetrahydrofolate reductase and angiotensin converting enzyme gene polymorphisms in two genetically and diagnostically distinct cohort of Alzheimer patients

The role of methylenetetrahydrofolate reductase (MTHFR) and angiotensin converting enzyme (ACE) gene polymorphisms as risk factors for the occurrence of Alzheimer's disease (AD) is still controversial. In this study, we investigated the common MTHFR C677-->T and ACE insertion/deletion (I/D) gene polymorphisms as risk factors for AD in two genetically and diagnostically distinct cohort of Alzheimer's patients. We analyzed a neuropathologically confirmed American cohort of 124 AD patients and 97 elderly controls, and a clinically diagnosed Italian cohort of 126 probable AD cases, 106 elderly controls, and a community-based sample of 1232 subjects aged under 65 years. No difference was found in polymorphism distribution between cases and controls in both study cohorts. We also tested a possible association between the polymorphisms investigated. No interaction was found between the MTHFR and ACE alleles. Moreover, no association was found for the ACE and MTHFR polymorphisms with age at onset, disease duration and MMSE score at observation. Thus, in our study, MTHFR C677-->T and ACE I/D polymorphisms do not appear to confer an added risk for AD.