Possible association between ABCC8 C49620T polymorphism and type 2 diabetes in a Nigerian population

Association of ABCC8 gene variants with response to sulfonylurea in type 2 diabetes mellitus

Background

Diabetes mellitus (DM) is associated with high blood glucose levels and sulfonylureas (SFUs) are one of the treatment options for DM. SFUs bind to sulfonylurea-1 receptor (SUR1), which is encoded by the ABCC8 gene and leads to blood glucose reduction. Genetic variants like rs757110 and rs1799854 of ABCC8 can influence the response to the drug's efficiency. Therefore, this study aimed to investigate the association between the ABCC8 rs757110 and rs1799854 genetic variants and response to SFUs treatment.

Methods

Totally, 61 DM patients with SFUs treatment were included. Baseline characteristics of the patients were recorded and 5 ml of blood was taken from each patient. After DNA extraction, a sequence containing rs757110 and rs1799854 was synthesized by the PCR method, and the PCR products were used for Sanger sequencing.

Results

Frequencies of GG, GA, and AA genotypes of rs1799854 variant was 12 (40%), 14 (46.7%), and 4 (13.3%), and the frequencies of CC, AC, and AA genotypes for rs757110 variant was 3 (9.7%), 5 (16.1%) and 23 (74.2%) in, respectively. Patients with different genotypes had the same age, BMI (body mass index), initial FBS (Fasting blood sugar), initial HbA1c, treatment duration, gender and history of smoking, alcohol consumption, and exercise. There was no significant difference in FBS and HbA1c changes after SFUs treatment between patients with rs757110 variant (p = 0.39 for FBS and p = 0.76 for HbA1c) and rs1799854 (p = 0.24 for FBS and p = 0.36 for HbA1c).

Conclusion

The rs1799854 and rs757110 variants of the ABCC8 gene had no significant influence on response to SFUs treatment.

The Mutation Spectrum of Rare Variants in the Gene of Adenosine Triphosphate (ATP)-Binding Cassette Subfamily C Member 8 in Patients with a MODY Phenotype in Western Siberia

During differential diagnosis of diabetes mellitus, the greatest difficulties are encountered with young patients because various types of diabetes can manifest themselves in this age group (type 1, type 2, and monogenic types of diabetes mellitus, including maturity-onset diabetes of the young (MODY)). The MODY phenotype is associated with gene mutations leading to pancreatic-β-cell dysfunction. Using next-generation sequencing technology, targeted sequencing of coding regions and adjacent splicing sites of MODY-associated genes (HNF4A, GCK, HNF1A, PDX1, HNF1B, NEUROD1, KLF11, CEL, PAX4, INS, BLK, KCNJ11, ABCC8, and APPL1) was carried out in 285 probands. Previously reported missense variants c.970G>A (p.Val324Met) and c.1562G>A (p.Arg521Gln) in the ABCC8 gene were found once each in different probands. Variant c.1562G>A (p.Arg521Gln) in ABCC8 was detected in a compound heterozygous state with a pathogenic variant of the HNF1A gene in a diabetes patient and his mother. Novel frameshift mutation c.4609_4610insC (p.His1537ProfsTer22) in this gene was found in one patient. All these variants were detected in available family members of the patients and cosegregated with diabetes mellitus. Thus, next-generation sequencing of MODY-associated genes is an important step in the diagnosis of rare MODY subtypes.

Association of KATP variants with CMD and RAP in CAD patients with increased serum lipoprotein(a) levels

CONTEXT

Refractory angina pectoris (RAP) is a specific subtype of coronary artery disease (CAD). Lipoprotein(a) [Lp(a)] and its induced coronary microvascular dysfunction (CMD) play an important role in pathogenesis of RAP, but its metabolism was mostly genetically determined. ATP-sensitive potassium channels (KATP) is involved in lipid metabolism and microvascular homeostasis, and becomes a promising target for the management of Lp(a) and its related RAP.

OBJECTIVE

To investigate associations of KATP variants with hyperlipoprotein(a)emia, CMD and RAP in CAD patients.

DESIGN, PATIENTS, SETTINGS

A total of 1,148 newly diagnosed CAD patients were prospectively selected, and divided into control [Lp(a) < 180 mg/dL] and case [Lp(a) ≥ 180 mg/dL, hyperlipoprotein(a)emia] group.

METHODS

9 KATP variants were genotyped by MassARRAY system. The expression profile of exosome-derived microRNAs (exo-miRs) was identified by next-generation sequencing, and the expression levels of differentially expressed exo-miRs were evaluated by qRT-PCR in verification cohort.

RESULTS

Three KATP variants were associated with increased risk of hyperlipoprotein(a)emia in CAD patients as follows: rs2285676 (AA + GA genotype, adjusted OR = 1.44, 95% CI: 1.10-1.88, P = 0.008), rs1799858 (CC genotype, adjusted OR = 1.33, 95% CI: 1.03-1.73, P = 0.030), and rs141294036 (CC genotype, adjusted OR = 1.43, 95% CI: 1.10-1.87, P = 0.008). Only rs141294036 was associated with increased risk of CMD (CC genotype, adjusted OR = 1.62, 95% CI: 1.23-2.13, P = 0.001), and further with increased RAP risk (CC genotype, adjusted HR = 2.05, 95% CI: 1.22-3.43, P = 0.007) after median follow-up of 50.6-months. Between the two genotypes of rs141294036, 152 exo-miRs were significantly differentially expressed, only 10 exo-miRs (miR-7110-3p, miR-548az-5p, miR-214-3p, let-7i-5p, miR-218-5p, miR-128-3p, miR-378i, miR-625-3p, miR-128-1-5p and miR-3187-3p) were further confirmed in RAP patients with hyperlipoprotein(a)emia and CMD.

CONCLUSION

KATP rs141294036 may serve a potential genetic marker for hyperlipoprotein(a)emia, CMD and RAP in CAD patients.

Associations of ATP-Sensitive Potassium Channel’s Gene Polymorphisms With Type 2 Diabetes and Related Cardiovascular Phenotypes

Type 2 diabetes (T2D) is characterized by increased levels of blood glucose but is increasingly recognized as a heterogeneous disease, especially its multiple discrete cardiovascular phenotypes. Genetic variations play key roles in the heterogeneity of diabetic cardiovascular phenotypes. This study investigates possible associations of ATP-sensitive potassium channel (KATP) variants with cardiovascular phenotypes among the Chinese patients with T2D. Six hundred thirty-six patients with T2D and 634 non-diabetic individuals were analyzed in the study. Nine KATP variants were determined by MassARRAY. The KATP rs2285676 (AA + GA, OR = 1.43, 95% CI: 1.13–1.81, P = 0.003), rs1799858 (CC, OR = 1.42, 95% CI: 1.12–1.78, P = 0.004), and rs141294036 (CC, OR = 1.45, 95% CI: 1.15–1.83, P = 0.002) are associated with increased T2D risk. A follow-up of at least 45.8-months (median) indicates further association between the 3 variants and risks of diabetic-related cardiovascular conditions. The associations are categorized as follows: new-onset/recurrent acute coronary syndrome (ACS) (rs2285676/AA + GA, HR = 1.37, 95% CI: 1.10–1.70, P = 0.005; rs141294036/TT + CT, HR = 1.59, 95% CI: 1.28–1.99, P < 0.001), new-onset stroke (rs1799858/CC, HR = 2.58, 95% CI: 1.22–5.43, P = 0.013; rs141294036/CC, HR = 2.30, 95% CI: 1.16–4.55, P = 0.017), new-onset of heart failure (HF) (rs1799858/TT + CT, HR = 2.78, 95% CI: 2.07–3.74, P < 0.001; rs141294036/TT + CT, HR = 1.45, 95% CI: 1.07–1.96, P = 0.015), and new-onset atrial fibrillation (AF) (rs1799858/TT + CT, HR = 2.05, 95% CI: 1.25–3.37, P = 0.004; rs141294036/CC, HR = 2.31, 95% CI: 1.40–3.82, P = 0.001). In particular, the CC genotype of rs1799858 (OR = 2.38, 95% CI: 1.11–5.10, P = 0.025) and rs141294036 (OR = 1.95, 95% CI: 1.04–3.66, P = 0.037) are only associated with the risk of ischemic stroke while its counterpart genotype (TT + CT) is associated with the risks of HF with preserved ejection fraction (HFpEF) (rs1799858, OR = 3.46, 95% CI: 2.31–5.18, P < 0.001) and HF with mildly reduced ejection fraction (HFmrEF) (rs141294036, OR = 2.74, 95% CI: 1.05–7.15, P = 0.039). Furthermore, the 3 variants are associated with increased risks of abnormal serum levels of triglyceride (TIRG) (≥ 1.70 mmol/L), low-density lipoprotein cholesterol (LDL-C) (≥ 1.40 mmol/L), apolipoprotein B (ApoB) (≥ 80 mg/dL), apolipoprotein A-I (ApoA-I) level (< 120 mg/dL), lipoprotein(a) Lp(a) (≥ 300 mg/dL) and high-sensitivity C-reactive protein (HsCRP) (≥ 3.0 mg/L) but exhibited heterogeneity (all P < 0.05). The KATP rs2285676, rs1799858, and rs141294036 are associated with increased risks of T2D and its related cardiovascular phenotypes (ACS, stroke, HF, and AF), but show heterogeneity. The 3 KATP variants may be promising markers for diabetic cardiovascular events favoring “genotype-phenotype” oriented prevention and treatment strategies.

Clinical and Genetic Analysis of KATP Variants With Heart Failure Risk in Patients With Decreased Serum ApoA-I Levels

CONTEXT

Lower serum concentration of apolipoprotein A-I (ApoA-I) is causally associated with heart failure (HF) risk. Adenosine triphosphate-sensitive potassium channels (KATP), as gating channels coupling vascular reactivity and metabolism with ischemic protection, become a new potential target of management for HF. The KATP gene sequence is highly polymorphic and has a high degree of genetic heterogeneity.

OBJECTIVE

This work aimed to determine whether KATP variants predict the risks of decreased ApoA-I concentration and its related HF.

METHODS

A total of 634 individuals, including 317 patients with decreased ApoA-I concentration (< 120 mg/dL) and 317 counterpart participants (≥ 120 mg/dL), were retrospectively selected. Five KATP variants were genotyped through the MassARRAY platform. Exosome-derived microRNAs (exo-miRs) expression profiles were identified by next-generation sequencing, and the top 10 differentially expressed (DE) exo-miRs were verified using quantitative polymerase chain reaction in a validation cohort of 240 individuals with decreased ApoA-I concentration.

RESULTS

KATP rs141294036 was related to an increased risk of lower ApoA-I levels (adjusted odds ratio [OR] = 1.95, P = .002) and HF incidence (adjusted OR = 2.38, P = .009), especially heart failure with preserved ejection fraction (HFpEF; adjusted OR = 2.13, P = .015). After a median 48.6-month follow-up, participants carrying the CC genotype of rs141294036 were associated with an elevated HF rehospitalization risk (adjusted hazard ratio = 1.91, P = .005). Thirty-six exo-miRs were significantly DE between different genotypes of rs141294036 in participants with lower ApoA-I levels, but only 5 exo-miRs (miR-31-5p, miR-126-5p, miR-106a-5p, miR-378i, and miR-181c-5p) were further confirmed.

CONCLUSION

KATP rs141294036 was associated with increased risks of lower ApoA-I levels, HF incidence (especially HFpEF), and HF rehospitalization in those with the 5 confirmed exo-miRs and its related metabolic pathways.

Genetic predisposition and bioinformatics analysis of ATP-sensitive potassium channels polymorphisms with the risks of elevated apolipoprotein B serum levels and its related arteriosclerosis cardiovascular disease

Serum concentration of apolipoprotein B (Apo B) is causally associated with arteriosclerosis cardiovascular disease (ASCVD) risk. Whether ATP-sensitive potassium channels (KATP) variants predict the risk of increased Apo B concentration (≥ 80 mg/dL) and related ASCVD remain less clear. We recruited 522 subjects with elevated Apo B concentration (≥ 80 mg/dL) and 522 counterpart subjects (< 80 mg/dL) from South China to assess the associations of KATP variants (rs11046182, rs78148713, rs145456027 and rs147265929) with the risks of increased Apo B serum concentration (≥ 80 mg/dL), carotid artery stenosis (CAS) ≥ 50% and new-onset ischemic stroke (IS). Our results showed that only KATP SNP rs11046182 (GG genotype) was associated with increased risk of Apo B ≥ 80 mg/dL (adjusted OR=2.17, P<0.001) and CAS ≥ 50% (adjusted OR=2.63, P=0.011). After median 50.6-months follow-up, subjects carrying GG genotype of rs11046182 were associated with higher risk of new-onset IS (adjusted HR=2.24, P=0.024). Further, the exosome-derived microRNAs (exo-miRs) expression profile was identified by next-generation sequencing. 41 exo-miRs were significantly differentially expressed under cross-talk status between high Apo B level (≥ 80 mg/dL) and KATP rs11046182. Our study demonstrated that KATP variant rs11046182 was associated with higher risks of elevated serum Apo B levels and its related ASCVD, and the possible mechanism was related to specific exo-miRs expression profile of KATP rs11046182.

Significant association of LXRβ (NR1H2) polymorphisms (rs28514894, rs2303044) with type 2 diabetes mellitus and laboratory characteristics

Purpose

To investigate if single-nucleotide polymorphisms (SNPs) in the NR1H2 gene encoding LXRβ contribute to the development of type-2 diabetes mellitus (T2DM) and whether genotypes of two NR1H2 polymorphisms, rs28514894 and rs2303044, are associated with laboratory characteristics of T2DM patients.

Method

A total of 900 subjects (450 T2DM cases and 450 healthy subjects) of Iranian ancestry were genotyped for NR1H2 polymorphisms via ARMS-PCR and PCR-RFLP techniques.

Result

Our findings showed a significant correlation between both polymorphisms and increased risk of T2DM. The haplotype analysis showed an association between the C A haplotype with enhanced risk of T2DM. In T2DM patients, the mean level of HbA1C and BUN significantly differed among carriers of CC and TT genotypes of the rs28514894 polymorphism (P = 0.05 and P < 0.0001, respectively); while in the control group, no significant difference was noticed between subjects with these genotypes. The mean BUN levels also significantly differed among carriers of TC and TT genotypes of this variant in T2DM patients (P = 0.01) and controls (P = 0.04). As for rs2303044 polymorphism, only the mean BUN level significantly differed between GA and GG carriers in T2DM patients (P = 0.006). Compared with CT and TT genotypes, the CC genotype of rs28514894 polymorphism was more frequent in overweight T2DM patients ( 25 < body mass index < 30).

Conclusions

The present research provided the first documents of the correlation of NR1H2 rs28514894 and rs2303044 polymorphisms with susceptibility to T2DM. Replicated case-control studies on larger populations are needed to validate these findings.

Association of KATP Gene Polymorphisms with Dyslipidemia and Ischemic Stroke Risks Among Hypertensive Patients in South China

ATP-sensitive potassium channels (KATP) couple vascular reactivity and metabolism with ischemic protection which makes them potential targets for prevention and management of ischemic stroke (IS). This study investigates the potential association between KATP polymorphisms and hypertension (HTN), dyslipidemia, and consequently ischemic stroke (IS). Nine hundred and fourteen (914) patients genotyped for KATP polymorphisms (rs2285676, rs1799858, rs4148671, rs61928479, and rs141294036) were analyzed. KATP rs141294036 (CC, adjusted OR = 1.59, 95%CI: 1.17-2.14, P = 0.003) was related to higher HTN risk. Meanwhile, rs2285676 (AA + GA, adjusted OR = 1.53, 95%CI: 1.08-2.19, P = 0.018) was associated with increased triglyceride level (≥ 1.7 mmol/L). rs2285676 (AA + GA, adjusted OR = 1.80, 95% CI: 1.24-2.61, P = 0.002), rs1799858 (TT + CT, adjusted OR = 1.68, 95% CI: 1.17-2.42, P = 0.005), and rs141294036 (TT + CT, adjusted OR = 1.90, 95% CI: 1.30-2.78, P = 0.001) were related to increased low-density lipoprotein cholesterol (≥ 1.8 mmol/L). rs2285676 (AA + GA, adjusted OR = 2.57, 95% CI: 1.74-3.82, P < 0.001) and rs141294036 (TT + CT, adjusted OR = 1.93, 95% CI: 1.27-2.93, P = 0.002) were related to increased apolipoprotein B (≥ 65 mg/dL). In addition, the 5 KATP polymorphisms were non-correlated with three types of dyslipidemia (total cholesterol, high-density lipoprotein cholesterol, and apolipoprotein AI). After median 50.6 month of follow-up, participants carrying CC genotype of rs141294036 showed correlation with elevated risk of new onset IS (adjusted HR = 2.55, 95% CI: 1.23-5.27, P = 0.012). These novel findings suggest that KATP rs141294036 is associated with increased risk of HTN, dyslipidemia, and IS. Based on these correlations, KATP rs141294036 could be a promising target for early and personalized therapeutics as well as prevention strategies for the aforementioned clinical pathologies.

Diabetes and Genetics: A Relationship Between Genetic Risk Alleles, Clinical Phenotypes and Therapeutic Approaches

Unveiling human genome through successful completion of Human Genome Project and International HapMap Projects with the advent of state of art technologies has shed light on diseases associated genetic determinants. Identification of mutational landscapes such as copy number variation, single nucleotide polymorphisms or variants in different genes and loci have revealed not only genetic risk factors responsible for diseases but also region(s) playing protective roles. Diabetes is a global health concern with two major types - type 1 diabetes (T1D) and type 2 diabetes (T2D). Great progress in understanding the underlying genetic predisposition to T1D and T2D have been made by candidate gene studies, genetic linkage studies, genome wide association studies with substantial number of samples. Genetic information has importance in predicting clinical outcomes. In this review, we focus on recent advancement regarding candidate gene(s) associated with these two traits along with their clinical parameters as well as therapeutic approaches perceived. Understanding genetic architecture of these disease traits relating clinical phenotypes would certainly facilitate population stratification in diagnosing and treating T1D/T2D considering the doses and toxicity of specific drugs.

ATP-sensitive potassium channels gene polymorphism rs1799858 affects the risk of macro-/micro-vascular arteriosclerotic event in patients with increased low-density lipoprotein cholesterol levels

Background

Plasma concentration of low-density lipoprotein cholesterol (LDL-C) is causally related to the risk of arteriosclerotic events. Whether ATP-sensitive potassium channels (KATP) genetic variants predict increased LDL-C concentration (≥1.8 mmol/L) and risk of macro-/micro-vascular arteriosclerotic event remain elusive.

Methods

A total of 320 subjects with increased LDL-C concentration (≥1.8 mmol/L) and 320 counterpart subjects (< 1.8 mmol/L) from the South China were enrolled in this study. Three KATP polymorphisms (rs1799858, rs4148671 and rs78148713) were genotyped by the Sequenom MassARRAY system. Binary logistic regression analysis was used to evaluate the association of the 3 KATP variants with increased LDL-C concentration and carotid artery stenosis (CAS) ≥50%. Two-way ANOVA was used to analyze the association of the 3 KATP variants with microalbumin in urine (MAU) and high-sensitivity C-reactive protein (HsCRP) levels. Cox proportional hazards regression analysis was used to retrospectively analyse the association of the optimal variant with the risk of new onset/recurrent acute myocardial infarction (AMI).

Results

Among the 3 studied KATP gene single nucleotide polymorphisms (SNPs), only rs1799858 (TT + CT genotype) was associated with elevated risk of LDL-C ≥ 1.8 mmol/L (adjusted OR = 2.25, 95% CI: 1.31–3.85, P = 0.003) and CAS ≥50% (adjusted OR = 2.80, 95% CI: 1.12–6.98, P = 0.028). KATP SNP rs1799858 was also associated with increased MAU (P = 0.013) and HsCRP (P = 0.027) levels. The follow-up for an average of 51.1-months revealed that participants carrying the T-allele (TT + CT) of rs1799858 was associated with high risk of new onset/recurrent AMI (adjusted HR = 2.90, 95% CI: 1.06–7.94, P = 0.038).

Conclusion

The KATP SNP rs1799858 may be an optimal genetic predisposition marker for increased LDL-C concentration (≥1.8 mmol/L) and its related macro-/micro-vascular arteriosclerotic event risk. The KATP variant rs1799858 was associated with higher risk of macro-/micro-vascular arteriosclerotic events in patients with elevated serum LDL-C levels.

Heritability and Genetics of Type 2 Diabetes Mellitus in Sub-Saharan Africa: A Systematic Review and Meta-Analysis

OBJECTIVES

Sub-Saharan Africa (SSA) is observing an accelerating prevalence rate of type 2 diabetes mellitus (T2DM) influenced by gene-environment interaction of modifiable and nonmodifiable factors. We conducted a systematic review and meta-analysis on the heritability and genetic risk of T2DM in SSA.

METHODS

We reviewed all published articles on T2DM in SSA between January 2000 and December 2019 and available in PubMed, Scopus, and Web of Science. Studies that reported on the genetics and/or heritability of T2DM or indicators of glycaemia were included. Data extracted included the study design, records of family history, pattern and characteristics of inheritance, genetic determinants, and effects estimates.

RESULTS

The pattern and characteristics of T2DM heritability in SSA are preference for maternal aggregation, higher among first degree compared to second-degree relatives; early age-onset (<50 years), and inherited abnormalities of beta-cell function/mass. The overall prevalence of T2DM was 28.2% for the population with a positive family history (PFH) and 11.2% for the population with negative family history (NFH). The pooled odds ratio of the impact of PFH on T2DM was 3.29 (95% CI: 2.40-4.52). Overall, 28 polymorphisms in 17 genes have been investigated in relation with T2DM in SSA. Almost all studies used the candidate gene approach with most (45.8%) of genetic studies published between 2011 and 2015. Polymorphisms in ABCC8, Haptoglobin, KCNJ11, ACDC, ENPP1, TNF-α, and TCF7L2 were found to be associated with T2DM, with overlapping effect on specific cardiometabolic traits. Genome-wide studies identified ancestry-specific signals (AGMO-rs73284431, VT11A-rs17746147, and ZRANB3) and TCF7L2-rs7903146 as the only transferable genetic risk variants to SSA population. TCF7L2-rs7903146 polymorphism was investigated in multiple studies with consistent effects and low-moderate statistical heterogeneity. Effect sizes were modestly strong [odds ratio = 6.17 (95% CI: 2.03-18.81), codominant model; 2.27 (95% CI: 1.50-3.44), additive model; 1.75 (95% CI: 1.18-2.59), recessive model]. Current evidence on the heritability and genetic markers of T2DM in SSA populations is limited and largely insufficient to reliably inform the genetic architecture of T2DM across SSA regions.

Genetic Determinants of Dyslipidemia in African-Based Populations: A Systematic Review

Identification of genetic/genomic factors contributing to dyslipidemia is of great interest to prevention and reduction of the onset and burden of cardiovascular diseases in Africa. This systematic review summarizes available data on genetic variants associated with dyslipidemia in populations within Africa. A PubMed and EMBASE database search was conducted to identify all studies published until June 2018 on genetic susceptibility to dyslipidemia in African-based populations, excluding familial hypercholesterolemia. All studies on genetic predispositions of dyslipidemia and respecting the preestablished inclusion criteria were included in this systematic review. Because of high heterogeneity, the data were summarized narratively. Twenty-two studies investigated mostly the targeted genetic variants. A total of 51 polymorphisms in 28 susceptibility genes to dyslipidemia have been associated with a particular trait in the African populations, and through variable effects. Most polymorphisms investigated in Northern Africa seemed to have consistent effects on increasing the level of low-density lipoprotein cholesterol (LDL-C), total cholesterol, and triglycerides in patients with diabetes, myocardial infarction, coronary artery disease, and metabolic syndrome. By contrast, only Ser447Ter and C49620T variants were associated with increased LDL-C in sub-Saharan Africa. Despite few studies available in this context in the literature, certain genetic variants were consistently associated with dyslipidemia especially in Northern Africa as highlighted in this analysis. Further data, particularly from genome-wide association studies, would help establish an African-specific reference for genetic susceptibility markers of dyslipidemia.