Angiotensin-converting enzyme insertion/deletion polymorphism genotyping error: the cause and a possible solution to the problem

The Impact of ACE Gene Variants on Acute-Phase Reactants in Children with Rheumatic Heart Disease

Rheumatic heart disease (RHD) is the most important sequela of upper respiratory group A Streptococcus (GAS) infection. The role of the common angiotensin-converting enzyme (ACE) insertion/deletion (I/D) variant in the disease and its subtypes remains uncertain. The acute-phase reactants (APRs) C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) form part of the Jones criteria for diagnosing RHD, and genetic factors are known to influence baseline CRP and ESR levels. Therefore, here, we investigated the relationship between the ACE I/D polymorphism and APR levels in RHD. A total of 268 individuals were recruited, including 123 RHD patients and 198 healthy controls. There was a trend toward a higher D allele frequency in RHD patients. The ACE I/D polymorphism genotype frequency and DD+ID allelic carriage were significantly associated with a high APR level (p = 0.04 and p = 0.02, respectively). These results highlight the importance of ACE I/D polymorphisms in RHD for disease stratification, but not for disease predisposition. Further studies in larger cohorts and different populations are now required to confirm this association and to explore the mechanism of this effect.

A Novel PCR Method for Detecting ACE Gene Insertion/Deletion Polymorphisms and its Clinical Application

Background

Angiotensin-converting enzyme (ACE) plays a major role in blood pressure regulation and cardiovascular homeostasis. The wide distribution and multifunctional properties of ACE suggest it’s involvement in various pathophysiological conditions.

Results

In this study, a novel visual detection method for ACE I/D polymorphisms was designed by integrating direct PCR without the need for DNA extraction using gold magnetic nanoparticles (GMNPs)-based lateral flow assay (LFA) biosensor. The entire detection procedure could enable the genotyping of clinical samples in about 80 min. The detection limit was 0.75 ng and results could be obtained in 5 min using the LFA device. Three hundred peripheral blood samples were analyzed using the direct PCR-LFA system and then verified by sequencing to determine accuracy and repeatability. A clinical preliminary study was then performed to analyze a total of 633 clinical samples.

Conclusions

After grouping based on age, we found a significant difference between the genotypes and the age of patients in the CHD group. The introduction of this method into clinical practice may be helpful for the diagnosis of diseases caused by large fragment gene insertions/deletions.

Influence of Angiotensin-converting Enzyme Insertion/Deletion Gene Polymorphism in Progression of Chagas Heart Disease

INTRODUCTION

Chagas disease (CD) is a neglected disease caused by the parasite Trypanosoma cruzi. One-third of infected patients will develop the cardiac form, which may progress to heart failure (HF). However, the factors that determine disease progression remain unclear. Increased angiotensin II activity is a key player in the pathophysiology of HF. A functional polymorphism of the angiotensin-converting enzyme (ACE) gene is associated with plasma enzyme activity. In CD, ACE inhibitors have beneficial effects supporting the use of this treatment in chagasic cardiomyopathy.

METHODS

We evaluated the association of ACE I/D polymorphism with HF, performing a case-control study encompassing 343 patients with positive serology for CD staged as non-cardiomyopathy (stage A; 100), mild (stage B1; 144), and severe (stage C; 99) forms of Chagas heart disease. For ACE I/D genotyping by PCR, groups were compared using unconditional logistic regression analysis and adjusted for nongenetic covariates: age, sex, and trypanocidal treatment.

RESULTS

A marginal, but not significant (p=0.06) higher prevalence of ACE I/D polymorphism was observed in patients in stage C compared with patients in stage A. Patients in stage C (CD with HF), were compared with patients in stages A and B1 combined into one group (CD without HF); DD genotype/D carriers were prevalent in the HF patients (OR = 2; CI = 1.013.96; p = 0.04).

CONCLUSIONS

Our results of this cohort study, comprising a population from the Northeast region of Brazil, suggest that ACE I/D polymorphism is more prevalent in the cardiac form of Chagas disease with HF.

Genetic and lifestyle predictors of ischemic stroke severity and outcome

BACKGROUND

Different models that include clinical variables and blood markers have been investigated to predict acute ischemic stroke treatment course and recovery.

AIM

The aim of the study was to investigate associations between lipid levels, lifestyle factors, hemostatic (F5, F2, SERPINE1, F13A1, and FGB), and atherogenic (APOA5 and ACE) gene variants and acute ischemic stroke (AIS) severity.

MATERIALS AND METHODS

This study included 250 patients with AIS in which F5, F2, SERPINE1, F13A1, FGB, APOA5, and ACE genotypes were determined. Total cholesterol (TC), high-density cholesterol, low-density cholesterol, and triglycerides concentrations were measured within 24 h of the AIS onset. Examination of the neurological deficit was done using National Institutes of Health Stroke Scale/Score (NIHSS).

RESULTS

APOA5 genotype [TC + CC] was more frequent (P = 0.026) in patients with the NIHSS score ≥ 21. Univariate regression analysis has shown that triglycerides (OR 0.55, 95% CI 0.34-0.91; P = 0.019), obesity (0.28, 95% CI 0.10-0.73; P = 0.010), age (OR 1.08, 95% CI 1.04-1.13; P < 0.001), and APOA5 genotype (TC + CC) (OR 2.40, 95% CI 1.10-5.25; P = 0.034) are significantly associated with a severe stroke. When all variables were included in model age (OR 1.06, 95% CI 1.01-1.11; P = 0.018), obesity (OR 0.25, 95% CI 0.08-0.77; P = 0.016) and APOA5 genotype (TC + CC) (OR 3.26, 95% CI 1.29-8.23; P = 0.012) remained significant for the risk of severe AIS.

CONCLUSION

APOA5 genotype (TC + CC), age, and obesity could be used as prognostic risk factors for a very severe stroke (NIHSS ≥ 21).

ACE Insertion/Deletion Polymorphism Associated with Caries in Permanent but Not Primary Dentition in Czech Children

OBJECTIVE

Dental caries is a multifactorial, infectious disease where genetic predisposition plays an important role. Insertion/deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE) has very recently been associated with caries in Polish children. The aim of this study was to analyze ACE I/D polymorphism in a group of caries-free children versus subjects affected by dental caries in the Czech population.

MATERIALS AND METHODS

In this case-control study, 182 caries-free children (with decayed/missing/filled teeth, DMFT = 0), 561 subjects with dental caries (DMFT ≥1) aged 13-15 years and 220 children aged 2-6 years with early childhood caries (ECC, dmft ≥1) were included. Genotype determination of ACE I/D polymorphism in intron 16 was based on the TaqMan method.

RESULTS

Although no significant differences in the allele or genotype frequencies between the caries-free children and those affected by dental caries were observed, statistically significant differences between the children with DMFT = 0 and the subgroup of 179 patients with high caries experience (DMFT ≥4; p < 0.01 and p < 0.05, respectively) were detected. The comparison of DD versus II+ID genotype frequencies between the patients with DMFT ≥1 or DMFT ≥4 and healthy children also showed significant differences (31.5% or 35.6% vs. 23.6%, p < 0.05 or p < 0.01, respectively). A gender-based analysis identified a significant difference in the DD versus II+ID genotype frequencies only in girls (p < 0.05). In contrast, no significant association of ACE I/D polymorphism with ECC in young children was found (p > 0.05).

CONCLUSIONS

ACE I/D polymorphism may be associated with caries in permanent but not primary dentition, especially in girls in the Czech population.