Association study of the β2-adrenergic receptor gene polymorphisms and hypertension in the Northern Han Chinese. PLoS One. 2011;6:e18590. [PMID: 21483652 DOI: 10.1371/journal.pone.0018590]

Single Nucleotide Polymorphisms in Amlodipine-Associated Genes and Their Correlation with Blood Pressure Control among South African Adults with Hypertension

Objective: This study describes the single nucleotide polymorphisms (SNPs) in amlodipine-associated genes and assesses their correlation with blood pressure control among South African adults with hypertension. Methods: In total, 304 hypertensive patients on amlodipine treatment belonging to the indigenous Swati, Xhosa and Zulu population groups of South Africa were recruited between June 2017 and June 2019. Participants were categorized into: controlled (blood pressure < 140/90 mmHg) and uncontrolled (blood pressure ≥ 140/90 mmHg) hypertension. Thirteen SNPs in amlodipine pharmacogenes with a high PharmGKB evidence base were selected and genotyped using MassArray (Agena BioscienceTM). Logistic regression was fitted to identify significant associations between the SNPs and blood pressure control with amlodipine. Results: The majority of the participants were females (76.6%), older than 45 years (89.1%) and had uncontrolled hypertension (52.3%). Of the 13 SNPs genotyped, five SNPs, rs1042713 (minor allele frequency = 45.9%), rs10494366 (minor allele frequency = 35.3%), rs2239050 (minor allele frequency = 28.7%), rs2246709 (minor allele frequency = 51.6%) and rs4291 (minor allele frequency = 34.4%), were detected among the Xhosa participants, while none were detected among the Swati and Zulu tribal groups. Variants rs1042713 and rs10494366 demonstrated an expression frequency of 97.5% and 79.5%, respectively. Variant TA genotype of rs4291 was significantly associated with uncontrolled hypertension. No association was established between blood pressure response to amlodipine and the remaining four SNPs. Conclusions: This study reports the discovery of five SNPs in amlodipine genes (rs2239050, rs2246709, rs4291, rs1042713 and rs10494366) among the indigenous Xhosa-speaking tribe of South Africa. In addition, the TA genotype of rs4291 was associated with blood pressure control in this cohort. These findings might open doors for more pharmacogenomic studies, which could inform innovations to personalised anti-hypertensive treatment in the ethnically diverse population of South Africa.

Association between the A46G polymorphism (rs1042713) in the β2-adrenergic receptor gene and essential hypertension susceptibility in the Chinese population: A PRISMA-compliant meta-analysis

BACKGROUND

Recently, many studies have been conducted to investigate the relationship between the A46G polymorphism in the β2-adrenergic receptor (ADRB2) gene and essential hypertension risk in the Chinese population. However, the results of previous studies were conflicting.

OBJECTIVES

The present study aimed to investigate the association between the ADRB2 A46G polymorphism and the risk of essential hypertension in the Chinese population.

METHODS

We performed a systematic search of possible relevant studies on PubMed, Embase, Ovid, Web of Science, China National Knowledge Infrastructure, Wanfang, and China Biology Medicine disc databases up to January 3, 2020. Two authors independently extracted information from included articles and assessed the quality of each study by the use of the Newcastle-Ottawa Scale. According to the extent of interstudy heterogeneity, either a random-effect model or a fixed-effect model was used to calculate the combined odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Finally, 16 studies containing 3390 cases and 2528 controls were included in our meta-analysis. Significant associations were found between the ADRB2 A46G polymorphism and essential hypertension risk in the Chinese population under four genetic models: allele genetic model (OR: 1.14, 95% CI: 1.06-1.23, P = .001, Pheterogeneity = .09), homozygote genetic model (OR: 1.29, 95% CI: 1.11-1.51, P = .001, Pheterogeneity = .25), dominant genetic model (OR: 1.17, 95% CI: 1.05-1.32, P = .005, Pheterogeneity = .04), and recessive genetic model (OR: 1.21, 95% CI: 1.05-1.38, P = .007, Pheterogeneity = .72).

CONCLUSION

The ADRB2 A46G polymorphism may increase the risk of essential hypertension in the Chinese population.

Hyperplasia suppressor gene polymorphisms and essential hypertension: a case-control association study in a central Han Chinese population

BACKGROUND

HSG (hyperplasia suppressor gene, also named Mitofusion-2, Mfn-2) gene polymorphisms have been studied as a candidate gene in essential hypertension, but no clear consensus has been reached in the Chinese population. To systematically explore their possible association, a case-control study was conducted in a central Chinese population.

METHODS AND RESULTS

We recruited 402 EH patients and 267 normotensive (NT) control subjects. A total of 6 tag SNPs of HSG gene were genotyped successfully by TaqMan assay. The results showed that genotype distribution and the allelic frequency of rs873457, rs2236384, rs4846085, and rs1474868 in the EH and NT groups were significantly different (P < 0.05), although those of rs2295281 and rs17037564 were not. rs2336384, rs873457, rs4846085 and rs1474868 were also closely associated with EH under the dominant genetic model (P < 0.05). Gender-based subgroup analyses showed that significant associations between rs873457, rs2336384, rs4846085, and rs1474868 and EH could be found in males, but not in females. Haplotype analysis indicated that the C-G-T-T-T-G haplotype was positively correlated with EH.

CONCLUSION

Our study suggested that HSG gene polymorphisms were significantly associated with EH in a central Han Chinese population, especially in male subjects.

Association of β-Adrenergic Receptor Gene Polymorphisms With Acute Coronary Syndrome and Cardiovascular Risk Factors in an Arab Population

We evaluated the association between beta-adrenergic receptor genes (ADRB1 and ADRB2) polymorphism, cardiovascular risk, and acute coronary syndrome (ACS) in individuals from an Arab ethnicity. A total of 388 Qatari participants were assessed and genotyped for ADRB1 (rs1801252 & rs1801253) and ADRB2 (rs1042718 & rs1042713) polymorphisms using allele-specific PCR. Minor allele frequencies (MAF) in each single-nucleotide polymorphisms (SNPs) did not show statistically significant difference between cases and controls. A higher proportion of patients with ACS had homozygous minor alleles (GG) for rs1801253 (28.8% vs 17.1%; P = .019) compared with controls. Among cases with ACS, there was an association of minor allele frequency (G) for rs1801253 with severe coronary artery stenosis (0.485 vs 0.428; P = .04) than that of insignificant stenosis (<50% stenosis). There was a 3-fold increased risk of significant coronary stenosis in patients with diabetes mellitus (DM) and carrier of rs1801253 genotypes with dominant model ( P = .01) and recessive model ( P = .05). There is a possible synergic association between DM, carrier of ADRB1 (Arg389Gly) variants, and significant coronary artery stenosis among Arabs. Further prospective studies with larger sample sizes are warranted to support our findings.

ADRB2 polymorphisms in allergic asthma in Han Chinese children

BACKGROUND

Single-nucleotide polymorphisms (SNPs) in the human β2 adrenergic receptor (ADRB2) gene have been linked to pathogenesis of and treatment responses in asthma. In China, where asthma is common, little information exists regarding ADRB2 variants and their effects on asthma. The current study sought to investigate the relationship between variations in ADRB2 and childhood asthma.

METHODS

Blood samples were collected from 298 pediatric asthma cases treated in our hospital from July 2013 to September 2014; 304 samples were collected from healthy children for a control group. Six loci (at base positions -47, 79, -2387, 46, 523, and 491) of ADRB2 were genotyped using the TaqMan probe assay; SHEsis was used to determine haplotypes. Allele frequencies and genotype distributions were compared between groups using chi square and t tests.

RESULTS

No significant differences in genotype or allele frequencies were found between the groups for the polymorphic loci -2387 bp (T>C), 46 bp (G>A), and 523 bp (C>A) (p > 0.05). However, genotype frequencies for the ADRB2 SNPs at -47 bp (C>T) and 79 bp (G>C) differed significantly between asthma and control groups (p < 0.05). Further, linkage disequilibrium was found between these 2 SNPs (D' = 0.990, r(2) = 0.962), as well as between SNPs at 46 and 523 bp (D' = 0.985, r(2) = 0.607). Finally, of the 4 haplotypes analyzed in these samples (haplotypes III, IV, IX, and XI), the frequency of haplotype III was significantly lower in the asthma group than the control group (p < 0.05; odds ratio [OR] = 0.72; 95% confidence interval [CI], 0.48 to 0.97).

CONCLUSION

Variations of ADRB2 at base positions -47 (C>T) and 79 (G>C), as well as haplotype III, may contribute to susceptibility to childhood asthma.

β-2 Adrenergic receptor gene polymorphism and response to propranolol in cirrhosis

AIM: To evaluate the association of β-2 adrenergic receptor (β₂-AR) gene polymorphism with response of variceal pressure to propranolol in cirrhosis.

METHODS: Sixty-four non-related cirrhotic patients participated in this study and accepted variceal pressure measurement before and after propranolol administration. Polymorphism of the β₂-AR gene was determined by directly sequencing of the polymerase chain reaction products from the DNA samples that were prepared from the patients.

RESULTS: The prevalence of Gly16-Glu/Gln27 and Arg16-Gln27 homozygotes, and compound heterozygotes was 29.7%, 10.9%, and 59.4%, respectively. Patients with cirrhosis with Gly16-Glu/Gln27 homozygotes had a greater decrease of variceal pressure after propranolol administration than those with Arg16-Gln27 homozygotes or with compound heterozygotes (22.4% ± 2.1%, 13.1% ± 2.7% and 12.5% ± 3.1%, respectively, P < 0.01).

CONCLUSION: The variceal pressure response to propranolol was associated with polymorphism of β₂-AR gene. Patients with the Gly¹⁶-Glu/Gln²⁷ homozygotes probably benefit from propranolol therapy.

G-protein beta 3 subunit polymorphisms and essential hypertension: a case-control association study in northern Han Chinese

OBJECTIVE

To explore the association between the three polymorphisms [ C825T, C1429T and G(-350)A] of the gene encoding the G protein beta 3 subunit (GNB3) and hypertension by performing a case-control study in the northern Han Chinese population.

METHODS

We recruited 731 hypertensive patients and 673 control subjects (the calculated power value was > 0.8). Genotyping was performed to identify C825T, C1429T and G(-350)A polymorphisms using the TaqMan assay. Comparisons of allelic and genotypic frequencies between cases and controls were made by using the chi-square test. Logistic regression analyses were performed to investigate the relationships between the three polymorphisms of GNB3 gene under different genetic models (additive, dominant and recessive models).

RESULTS

The genotype distribution and allele frequencies of C825T, C1429T and G(-350)A polymorphisms did not differ significantly between hypertensive patients and control subjects, either when the full sample was assessed, or when the sample was stratified by gender. No significant association was observed between C825T, C1429T and G(-350)A polymorphisms and the risk of essential hypertension in any genetic model. Linkage disequilibrium was only detected between C825T and C1429T polymorphisms. Haplotype analyses observed that none of the three estimated haplotypes significantly increased the risk of hypertension.

CONCLUSIONS

Our study suggested that the GNB3 gene polymorphisms [C825T, C1429T and G(-350)A] were not significantly associated with essential hypertension in northern Han Chinese population.

Beta2-Adrenergic Receptor Gene Polymorphisms in Egyptian Patients with Acute Myocardial Infarction

Background. Beta2-adrenergic receptor (ADRB2) gene polymorphisms, Arg16Gly and Gln27Glu, have been implicated in the pathogenesis of cardiovascular diseases. The aim of this study was to determine the association of these two polymorphisms with the risk of myocardial infarction (MI) in the Egyptian population. Methods. Blood samples were collected from 68 MI patients and 75 healthy controls. They were assessed for the presence of cardiovascular risk factors and genotyped for the Arg16Gly (rs1042713) and Gln27Glu (rs1042714) polymorphisms using allelic-discrimination polymerase chain reaction. Results. There is no significant difference in genotype and allele frequencies at codon 16 between MI patients and controls (P=0.919). However, at codon 27, MI risk was higher in Gln27 homozygous participants than in Glu27 carriers (P=0.045). The haplotype frequency distribution showed significant difference among cases and controls (P=0.002); homozygotes for Gly16/Gln27 haplotype were more susceptible to MI than Gly16/Glu27 carriers. Patients with Arg16/Gln27 haplotype had higher serum total cholesterol levels (P<0.05) and lower frequency of diabetes in MI patients (P<0.01). However, both Glu27 genotypes and haplotype showed lower frequency of hypertension (P<0.001). Conclusions. Our findings suggested that the ADRB2 gene polymorphisms may play an important role in susceptibility of MI among Egyptian population.

Role of leptin receptor gene polymorphisms in susceptibility to the development of essential hypertension: a case-control association study in a Northern Han Chinese population

In order to explore the potential association between the leptin receptor (LEPR) gene polymorphisms and essential hypertension (EH) risk in the Northern Han Chinese population, we recruited 823 hypertensive subjects and 491 healthy control subjects from the Northern Han Chinese. Genotyping was performed to identify the Lys109Arg, Gln223Arg and Lys656Asn polymorphisms of the LEPR gene. Significant associations were found in a dominant genetic model ([GG+AG] vs AA), P=0.007, odds ratio (OR)=3.697, 95% confidence interval (CI) 1.442–9.482), and in homozygote comparison (GG vs AA, P=0.005, OR=3.890, 95% CI 1.501–10.077) for the Gln223Arg polymorphism. No significant association could be found between Lys109Arg or Lys656Asn polymorphism and EH risk. Linkage disequilibrium was detected between the Lys109Arg and Gln223Arg polymorphisms, and haplotype analyses identified that the G-A haplotype was a protective haplotype for EH. Our studies demonstrated that the LEPR Gln223Arg polymorphism had an important role in a patient's susceptibility to EH in the Northern Han Chinese population.

A Hypertension Gene: Are We There Yet?

Cardiovascular diseases are the leading cause of death worldwide. Essential hypertension is a major risk factor for the development of other cardiovascular diseases and is caused by a combination of environmental and genetic factors, with up to 50% of blood pressure variance currently attributed to an individual's genetic makeup. By studying genes that cause monogenic forms of hypertension and pathways relevant to blood pressure control, a number of polymorphisms have been identified that increase an individual's risk of developing high blood pressure. We report on candidate gene association studies and genome-wide association studies that have been performed to date in the field of hypertension research. It is becoming clear that for the majority of people there is no single gene polymorphism that causes hypertension, but rather a number of common genetic variants, each having a small effect. Using pharmacogenomics to personalize the treatment of hypertension holds promise for achieving and sustaining normotensive pressures quickly, while minimizing the risk of adverse reactions and unwanted side-effects. This will decrease the risk of stroke and myocardial infarction in individuals and lead to a reduced burden of disease upon society as a whole.