Evaluating genomic DNA extraction methods from human whole blood using endpoint and real-time PCR assays

Techniques, procedures, and applications in host genetic analysis

This chapter overviews genetic techniques' fundamentals and methodological features, including different approaches, analyses, and applications that have contributed to advancing health and disease. The aim is to describe laboratory methodologies and analyses employed to understand the genetic landscape of different biological contexts, from conventional techniques to cutting-edge technologies. Besides describing detailed aspects of the polymerase chain reaction (PCR) and derived types as one of the principles for many novel techniques, we also discuss microarray analysis, next-generation sequencing, and genome editing technologies such as transcription activator-like effector nucleases (TALENs) and the clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) systems. These techniques study several phenotypes, ranging from autoimmune disorders to viral diseases. The significance of integrating diverse genetic methodologies and tools to understand host genetics comprehensively and addressing the ethical, legal, and social implications (ELSI) associated with using genetic information is highlighted. Overall, the methods, procedures, and applications in host genetic analysis provided in this chapter furnish researchers and practitioners with a roadmap for navigating the dynamic landscape of host-genome interactions.

Evaluation of ADRB2 and OATP2A1 genetic polymorphisms in Indian patients with primary open-angle glaucoma

The emergence of adrenergic β2-receptor (ADRB2) blockers has revolutionized glaucoma treatment, while the discovery of prostaglandin analogs has further expanded therapeutic options. Organic anion transporting polypeptide 2A1 (OATP2A1/SLCO2A1) facilitates the corneal transport of topical prostaglandins into anterior segment of eye. Our study aims to elucidate the prevalence of genetic polymorphisms in the ADRB2 and OATP2A1 to address variations in therapeutic responses among glaucoma patients. The study cohort comprised primary open-angle glaucoma patients (POAG, n = 77), compared to non-glaucomatous controls (n = 60) to identify polymorphisms rs1042713 (Arg16Gly, A > G) and rs1042714 (Gln27Glu, C > G) in the ADRB2 gene and rs34550074 (Ala396Thr, A > G) in OATP2A1 gene, using Sanger sequencing. Among the enrolled subjects (n = 137), the POAG group exhibited significantly elevated intraocular pressure ( P  < 0.001) and cup-to-disc ratio ( P  < 0.0001). The GA genotype of rs1042713 ( P  < 0.01) and the GG genotype of rs1042714 ( P  < 0.05) were positively associated with POAG, while rs34550074 ( P  > 0.05) showed no significant correlation with the disease. This study reveals the association of the ADRB2 gene polymorphisms with POAG, whereas OATP2A1 polymorphism did not show significant correlation.

Association of polymorphism of IL-17A, IL-17F, and IL-6 with Toxoplasma gondii infection susceptibility in HIV/AIDS patients in Shiraz, southern Iran

INTRODUCTION

Toxoplasma gondii infection is considered as one of the most important opportunistic infections and cause of death in HIV patients.

METHODS

In this cross-sectional study, 334 HIV positive patients were included. The molecular test was performed by the restriction fragment length polymorphism-polymerase chain reaction method. Allelic frequency, haplotype analyses, and linkage disequilibrium were calculated. The odds ratio was calculated. The linear regression model was used to analysis of interleukin (IL)-17A, IL-17F, and IL-6 single-nucleotide polymorphism genotypes in HIV patients with and without toxoplasmosis.

RESULTS

In total, 95 tested'patients (28.4%) were positive for toxoplasmosis. The risk of toxoplasma infection in the current study did not correlate with IL-17 and IL-6 polymorphism and the risk of contracting toxoplasma was also not significantly correlated in this study. There was no association between the frequency of alleles and the risk of toxoplasma infection in IL-17 haplotype analysis.

CONCLUSION

The findings of this study revealed that there were significant differences in the serum levels of IL-6 and IL-17A, but not IL-17F, between the case and control groups in various genetic models. However, these polymorphisms did not show a significant relationship with toxoplasma infection in HIV-positive patients. This study represents the first investigation in Iran to explore the role of IL-6 and IL-17 polymorphisms in toxoplasma infection among HIV-positive patients.

MicroRNA biogenesis machinery activation and lncRNA and REST overexpression as neuroprotective responses to fight inflammation in the hippocampus

Brain Long non-coding RNA (lncRNA) and microRNAs (miRs) play essential roles in the regulation of several important biological processes, including neuronal activity, cognitive processes, neurogenesis, angiogenesis, and neuroinflammation. In this context, the transcriptional repressor, RE1 silencing transcription factor (Rest), acts regulating the expression of neuronal genes as well as of lncRNAs and multiple miRNAs in the central nervous system. Nevertheless, its role in neuroinflammation was less explored. Here, we demonstrate, using an in vivo model of neuroinflammation induced by i.p. injection of LPS (0.33 mg/kg), that neuroinflammation increases gene expression of pro-inflammatory cytokines concomitant with the native and truncated forms of Rest and of non-coding RNAs. Additionally, the increased expression of enzymes Drosha ribonuclease III) (Drosha), Exportin 5 (Xpo5) and Endoribonuclease dicer (Dicer), associated with high expression of neuroprotective miRs 22 and 132 are indicative that the activation of biogenesis of miRs in the hippocampal region is a Central Nervous System (CNS) protective mechanism for the deleterious effects of neuroinflammation. Our results indicate that positive regulation of Rest gene expression in the hippocampal region by neuroinflammation correlates directly with the expression of miRs 22 and 132 and inversely with miR 335. In parallel, the confirmation of the possible alignment between the lncRNAs with miR 335 by bioinformatics corroborates with the sponge effect of Hottip and Hotair hybridizing and inhibiting the pro-inflammatory action of miR 335. This suggests the existence of a possible correlation between the activation of miR biogenesis machinery with increased expression of the transcription factor Rest, contributing to neuroprotection.

A report of 5 Indian families with multicentric carpotarsal osteolysis syndrome

Multicentric carpotarsal osteolysis syndrome (MCTO) is a rare autosomal dominant skeletal dysplasia characterised by swelling and restriction of movement in the wrist and ankle joints, as well as osteolysis of the carpal and tarsal bones, that can be misdiagnosed as juvenile idiopathic arthritis. We describe five Indian families with heterozygous nonrecurrent missense pathogenic variants in exon 1 of MAF bZIP transcription factor B (MAFB).

Shifting as an executive function separate from updating and inhibition in old age: Behavioral and genetic evidence

This study aimed to examine the organization of executive functions (EFs), specifically working memory updating, prepotent response inhibition, and mental-set shifting in old age, with a particular focus on determining whether the shifting function was behaviorally and genetically separated from the other functions. A total of 248 healthy older Chinese individuals participated, and multiple measures of executive functions were collected. Additionally, measures of fluid intelligence were included to explore the varying relationships between the three executive functions and this higher-order cognitive ability. Furthermore, genetic data were gathered and analyzed to investigate the associations between EFs and six candidate single-nucleotide polymorphisms (SNPs) mapped to dopaminergic, serotonergic, or glutamatergic genes. The results indicated that both the three-factor model and the two-factor model, which combined updating and inhibition, demonstrated a good fit. Furthermore, shifting was found to be behaviorally separated from the other two functions, and the correlation between shifting and fluid intelligence was smaller compared to the correlations between updating and inhibition with fluid intelligence. Moreover, the DRD2 SNPs showed significant associations with shifting, rather than with updating and inhibition. These findings provide evidence that shifting is distinct and separate from updating and inhibition, highlighting the diversity of EFs among older adults.

Association between Sex-Related ALOX5 Gene Polymorphisms and Lung Atopy Risk

Atopy is an exaggerated IgE-mediated immune response to foreign antigens in which metabolic abnormalities of the leukotrienes (LTs) pathway play a crucial role. Recent studies have described sex as a key variable in LT biosynthesis, partly explaining why treatment with anti-LT drugs in atopic subjects leads to better control of symptoms in women. In addition, variability in LT production is often associated with single nucleotide polymorphisms (SNPs) in the arachidonate 5-lipoxygenase (ALOX5) gene, which encodes the leukotriene-synthesizing enzyme machinery, 5-lipoxygenase (5-LO). This study aimed to investigate whether two SNPs of ALOX5 are implicated in sex differences in allergic diseases in a prospective cohort of 150 age- and sex-matched atopic and healthy subjects. Rs2029253 and rs2115819 were genotyped using allele-specific RT-PCR, and serum levels of 5-LO and LTB4 were measured by ELISA. Both polymorphisms are significantly more common in women than in men, and their influences on LT production vary as a function of sex, leading to a decrease in men's and an increase in women's serum levels of 5-LO and LTB4. These data represent a new resource for understanding sex-related differences in lung inflammatory diseases, partly explaining why women are more likely to develop allergic disorders than men.

The spectrum of neurological manifestations and genotype-phenotype correlation in Indian children with Gaucher disease

Gaucher disease (GD), one of the most frequent autosomal recessive lysosomal storage disorders, occurs due to bi-allelic pathogenic variants in the GBA1. Worldwide, the c.1448T>C (L483P) homozygous pathogenic variant is reported to be associated with neurological GD phenotype. Clinical distinction between GD1 and GD3 may be challenging due to subtle neurological features. Objective methods to evaluate neurological signs and saccades may help in early diagnosis. This study was conducted to assess the neurological phenotype, and its severity using a modified severity scoring tool (mSST), and the genotype-phenotype correlation. A total of 45 children aged 2 years 6 months to 15 years with a confirmed enzymatic and molecular diagnosis of GD with or without therapy were recruited. mSST tool was used to assess the severity of the neurological phenotype. A digital eye movement tracker (View Point Tracker) was used to assess eye movements. Clinical and genetic findings were analyzed. Out of 45 patients, 39 (86.7%) had at least one neurological phenotype detected using the mSST tool, with impairment of cognitive function (68.8%, 31/45) being the commonest feature. Thirty-two of 45 (71%) were assessed for saccadic eye movements using the eye tracker. Of these, 62.5% (20/32) had absent saccades. Four children (8.9%, 4/32) without clinical oculomotor apraxia had absent saccades on the viewpoint eye tracker. Overall, 77.7% (35/45), had homozygosity for c.1448T>C in GBA1 of which 91.4% (32/35) had neurological manifestations. Other alleles associated with neurological phenotype included c.1603C>T(p.R535C), c.1184C>T (p.S395F), c.115+1G>A (g.4234G>A), c.260G>A (p.R87Q) and c.1352A>G (p.Y451C). To conclude, in India, the c.1448T>C pathogenic variant in GBA1 is the commonest  and is associated with neurological phenotype of GD. Therefore, every patient of GD should be assessed using the mSST scoring tool for an early pick up of neurological features. The routine use of a viewpoint eye tracker in children with GD would be useful for early recognition of saccadic abnormalities.

Cyanobacterial Algal Bloom Monitoring: Molecular Methods and Technologies for Freshwater Ecosystems

Cyanobacteria (blue-green algae) can accumulate to form harmful algal blooms (HABs) on the surface of freshwater ecosystems under eutrophic conditions. Extensive HAB events can threaten local wildlife, public health, and the utilization of recreational waters. For the detection/quantification of cyanobacteria and cyanotoxins, both the United States Environmental Protection Agency (USEPA) and Health Canada increasingly indicate that molecular methods can be useful. However, each molecular detection method has specific advantages and limitations for monitoring HABs in recreational water ecosystems. Rapidly developing modern technologies, including satellite imaging, biosensors, and machine learning/artificial intelligence, can be integrated with standard/conventional methods to overcome the limitations associated with traditional cyanobacterial detection methodology. We examine advances in cyanobacterial cell lysis methodology and conventional/modern molecular detection methods, including imaging techniques, polymerase chain reaction (PCR)/DNA sequencing, enzyme-linked immunosorbent assays (ELISA), mass spectrometry, remote sensing, and machine learning/AI-based prediction models. This review focuses specifically on methodologies likely to be employed for recreational water ecosystems, especially in the Great Lakes region of North America.

Genetic variation in salt taste receptors impact salt intake and blood pressure

So far, few studies have examined the effect of salt taste receptors genetic variation on dietary intake in the Iranian population. We aimed to evaluate associations between single nucleotide polymorphisms (SNPs) in salt taste receptors' genes with dietary salt intake and blood pressure. A cross-sectional study was carried out among 116 randomly selected healthy adults aged ≥ 18 in Isfahan, Iran. Participants underwent sodium intake determination by 24-h urine collection, as well as dietary assessment by semi-quantitative food frequency questionnaire and blood pressure measurement. Whole blood was collected to extract DNA and genotype of SNP rs239345 in SCNN1B and rs224534, rs4790151 and rs8065080 in TRPV1 gene. Sodium consumption and diastolic blood pressure were significantly higher in carriers of the A-allele in rs239345 compared to subjects with the TT genotype (4808.4 ± 824.4 mg/day vs. 4043.5 ± 989.3 mg/day; P = 0.004) and 83.6 ± 8.5 mmHg vs. 77.3 ± 7.3 mmHg; P = 0.011), respectively. The level of sodium intake was lower in the TT genotype of TRPV1 (rs224534) than the CC genotype (3767.0 ± 713.7 mg/day vs. 4633.3 ± 793.5 mg/day; P = 0.012). We could not find any association between genotypes of all SNPs with systolic blood pressure as well as genotypes of rs224534, rs4790151 and rs8065080 with diastolic blood pressure. Genetic variations can relate with salt intake and consequently may associate with hypertension and finally cardiovascular disease risk in the Iranian population.

Diversity of Mitochondrial DNA Haplogroups and Their Association with Bovine Antral Follicle Count

Maternal origins based on the bovine mitochondrial D-loop region are proven to have two main origins: Bos taurus and Bos indicus. To examine the association between the maternal origins of bovine and reproductive traits, the complete mitochondrial D-loop region sequences from 501 Chinese Holstein cows and 94 individuals of other breeds were analyzed. Based on the results obtained from the haplotype analysis, 260 SNPs (single nucleotide polymorphism), 32 indels (insertion/deletion), and 219 haplotypes were identified. Moreover, the nucleotide diversity (π) and haplotype diversity (Hd) were 0.024 ± 0.001 and 0.9794 ± 0.003, respectively, indicating the abundance of genetic resources in Chinese Holstein cows. The results of the median-joining network analysis showed two haplogroups (HG, including HG1 and HG2) that diverged in genetic distance. Furthermore, the two haplogroups were significantly (p < 0.05) correlated with the antral follicle (diameter ≥ 8 mm) count, and HG1 individuals had more antral follicles than HG2 individuals, suggesting that these different genetic variants between HG1 and HG2 correlate with reproductive traits. The construction of a neighbor-joining phylogenetic tree and principal component analysis also revealed two main clades (HG1 and HG2) with different maternal origins: Bos indicus and Bos taurus, respectively. Therefore, HG1 originating from the maternal ancestors of Bos indicus may have a greater reproductive performance, and potential genetic variants discovered may promote the breeding process in the cattle industry.

Prevalence, Diversity, and Risk Factors for Cervical HPV Infection in Women Screened for Cervical Cancer in Belém, Pará, Northern Brazil

Background: Human papillomavirus (HPV) is the most common viral sexually transmitted infection of the reproductive tract, and cervical cancer is the most common HPV-related disease. This study estimated the prevalence, diversity of HPV genotypes, and associated risk factors in women screened for cervical cancer in northern Brazil. Methods: The cross-sectional study was conducted in Belém, Pará, in the Amazon region of Brazil, and it included 162 women who were spontaneously undergoing a Pap-smear routine. Epidemiological, sexual, and health-related information was collected by interviews, and cervical samples were collected for cytological examination and HPV-DNA detection. HPV genotypes were classified as low risk (LR) and high risk (HR) by nucleotide sequencing. Results: In total, 17.3% (28/162) of the participants had HPV-DNA, and LR-HPV was the most prevalent (71.4%). Among the 13 different types of HPV detected, HPV-11 was found most frequently (12/28; 42.9%), followed by HPV-31 (3/28; 10.7%). Of the participants with cytological alterations, HPV infection was detected in only four: two were diagnosed with low-grade squamous intraepithelial lesions (15.4%), one with atypical squamous cells of undetermined significance (7.7%), and one with atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesions (7.7%). Of the 61 women who presented a normal cytology, 13 (21.3%) had positive tests for HPV infection, 4 (8.2%) of which were positive for a high-risk genotype. Conclusion: The prevalence of HPV was high in Belém, Pará, and especially in women who had normal cytology results, which suggests the need for greater screening for HPV infection in women’s primary health care.

Pharmacogenetic variants influence vitamin K anticoagulant dosing in patients with mechanical prosthetic heart valves

Background: Vitamin K antagonists (VKAs) are class I oral anticoagulants that are widely prescribed following surgical heart valve implantation. The objective of this study was to quantify the relative effects of VKORC1, CYP2C9 and CYP4F2 genotypes in predicting VKA dosing. Materials & methods: A total of 506 South Indian patients with mechanical prosthetic heart valves who were prescribed oral VKAs, such as warfarin or acenocoumarol, were genotyped. The discriminatory ability of mutant genotypes to predict dose categories and bleeding events was assessed using regression analysis. Results: The VKORC1 rs9923231, CYP2C9*3 and CYP4F2*3 mutant genotypes significantly influenced VKA-dose requirements and explained 27.47% of the observed dose variation. Conclusion: These results support pharmacogenetic screening for initial VKA dosing among South Indian patients with mechanical prosthetic heart valves.

Detection of Ovine or Bovine Milk Components in Commercial Camel Milk Powder Using a PCR-Based Method

Food ingredient adulteration, especially the adulteration of milk and dairy products, is one of the important issues of food safety. The large price difference between camel milk powder, ovine, and bovine milk powder may be an incentive for the incorporation of ovine and bovine derived foods in camel milk products. This study evaluated the use of ordinary PCR and real-time PCR for the detection of camel milk powder adulteration based on the presence of ovine and bovine milk components. DNA was extracted from camel, ovine, and bovine milk powder using a deep-processed product column DNA extraction kit. The quality of the extracted DNA was detected by amplifying the target sequence from the mitochondrial Cytb gene, and the extracted DNA was used for the identification of milk powder based on PCR analysis. In addition, PCR-based methods (both ordinary PCR and real-time PCR) were used to detect laboratory adulteration models of milk powder using primers targeting mitochondrial genes. The results show that the ordinary PCR method had better sensitivity and could qualitatively detect ovine and bovine milk components in the range of 1% to 100% in camel milk powder. The commercial camel milk powder was used to verify the practicability of this method. The real-time PCR normalization system has a good exponential correlation (R² = 0.9822 and 0.9923) between ovine or bovine content and Ct ratio (specific/internal reference gene) and allows for the quantitative determination of ovine or bovine milk contents in adulterated camel milk powder samples. Accuracy was effectively validated using simulated adulterated samples, with recoveries ranging from 80% to 110% with a coefficient of variation of less than 7%, exhibiting sufficient parameters of trueness. The ordinary PCR qualitative detection and real-time PCR quantitative detection method established in this study proved to be a specific, sensitive, and effective technology, which is expected to be used for market detection.

Correlation between BTG3, CASP9 and LRP4 single-nucleotide polymorphisms and susceptibility to papillary thyroid carcinoma

Objective: To study the association of BTG3, CASP9 and LRP4 single-nucleotide polymorphisms with susceptibility to papillary thyroid carcinoma (PTC). Methods: The BTG3 rs9977638, CASP9 rs884363 and LRP4 rs898604 genotypes of 175 PTC patients and 175 controls were analyzed. Results: Rs9977638 TC genotype and CC genotype, rs884363 CC genotype and rs898604 GG genotype were related to a lower PTC susceptibility risk (p < 0.01). The risk of PTC susceptibility was higher when carrying BTG3 rs9977638 CC, CASP9 rs884363 AC and LRP4 rs898604 AG at the same time (p < 0.01). Conclusion: Combined BTG3, CASP9 and LRP4 genotype analysis has a certain application value in the diagnosis of PTC.

Mutations in exon region of BRCA1-related RING domain 1 gene and risk of breast cancer

Background

BRCA1‐associated RING Domain 1 (BARD1) is an important gene related to breast cancer development. However, the role of BARD1 mutations in breast cancer remains inconclusive. This study is to investigate the relationship between exon mutations of BARD1 gene and the risk of early‐onset breast cancer.

Methods

Totally, 60 cases of early‐onset breast cancer patients (age 30–40 years) and 240 healthy women (age 30–40 years) were enrolled. Exon mutations of BARD1 were detected and analyzed by direct sequencing and SNaPshot.

Results

The risk of breast cancer was increased by 3.475 times in carriers with deletion mutation at rs28997575 site of BARD1 (aOR₁ = 3.475, 95%CI = 1.302–9.276) (p = 0.013). The risk of breast cancer in carriers with GC genotype at rs2229571 site of BARD1 was reduced by 72.6% (aOR₁ = 0.274, 95%CI = 0.134–0.562) (p = 0.001), and that in carriers with CC genotype was reduced by 82.8% (aOR₁ = 0.172, 95%CI = 0.076–0.392) (p = 0.001). After stratification with family history, the difference of rs2229571 site mutation genotype was statistically significant (OR = −2.169, 95%CI = 0.016–0.828, p = 0.032). Additionally, the frequency distribution of breast cancer family history in the case group (15%) was significantly more than that in the control group (6.7%) (p = 0.037).

Conclusion

The deletion mutation at rs28997575 locus of the BARD1 gene can significantly increase the risk of breast cancer. The mutation genotype of rs2229571 locus can significantly reduce the risk of breast cancer. Family history is associated with BARD1 gene polymorphism. A family history of breast cancer may be a risk factor for breast cancer.

A mutation modulating DDX3Y gene expression cosegregates with the major Y-chromosomal haplogroups and with testis size in Hu sheep

Variations in the Y-chromosome are usually correlated with male-specific traits. However, this condition has been described only sporadically, even in human genetics. The present study was conducted to clone the full-length gene sequence of ovine DEAD-box helicase 3, Y-linked (DDX3Y), and investigate the effect of the expression and variation of DDX3Y on the reproductive traits of Hu sheep. Consequently, we identified the full coding sequence and genomic sequence of ovine DDX3Y. Quantitative PCR (qPCR) analysis showed that ovine DDX3Y was highly expressed in testis, and the expression level increased during testicular development. Furthermore, individuals with larger testis at 6 months expressed significantly more DDX3Y mRNA in the testis than individuals with smaller testis. Notably, a novel SNP (g. 12657 C>A) in the 3' untranslated region was identified in Hu sheep and Tan sheep according to the investigation of the full DDX3Y genomic sequence of 1069 individuals from nine sheep breeds. Association analysis revealed that the SNP was significantly related to testis size in Hu sheep. Meanwhile, Hu rams with the derived C allele showed significantly higher expression levels of DDX3Y in testis than those with the ancestral A allele. In addition, data mining in a previous study showed that the C allele cosegregated with the globally major Y-chromosomal haplogroups y-HA and y-HC, and the A allele is found in all rams with haplogroups y-HB1, y-HB2 and y-HD. This study suggests that the association of the Y-chromosomal haplogroups with testis size in Hu sheep can be extrapolated to the sheep population worldwide.

Development of a novel ssDNA aptamer targeting cardiac troponin I and its clinical applications

Cardiac troponin I (cTnI) is a specific biomarker of acute myocardial infarction (AMI). However, cTnI detection kits prepared with antibodies have many defects. Nucleic acid aptamers are sequences of single-strand DNA or RNA that can overcome the deficiency of antibodies. Herein, sandwich ELONA methods were established based on aptamers. Two selected ssDNA aptamers (Apt3 and Apt6) showed high binding affinity and sensibility (Apt3: Kd = 1.01 ± 0.07 nM, Apt6: k = 0.68 ± 0.05) and did not bind to the same domain of cTnI. Therefore, these two aptamers can be applied to the ELONA methods. The detection range of cTnI using the dual-aptamer sandwich ELONA method was 0.05-200 ng/mL, and the bioanalytical method verification results can meet the national standard of Chinese Pharmacopoeia (2020 Edition). There was no difference between results of the dual-aptamer sandwich ELONA method and the diagnostic results of serum obtained from 243 people (P = 0.39, P ˃ 0.05). The sensitivity and specificity of the ELONA with cTnI in serum were 96.46% and 93.85%, respectively. Compared with the FICA kit, which is clinically used, the consequences of ELONA method are closer to the diagnostic results. This study suggests that the aptamers Apt3 and Apt6 have high affinity and strong specificity and that the dual-aptamer sandwich ELONA method has a wide detection range and can be used to determine cTnI in serum, with potential applications in the diagnosis of AMIs.

PCSK9 E670G (rs505151) Variant and Coronary Artery Disease Risk Among Diabetics

Background: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is an enzyme in the family of proprotein convertases implicated in lipid metabolism and is a significant genetic risk factor in cardiovascular diseases among various populations. Aim of the Study: This study explored the correlation between the alleles of the rs505151 (E670G) locus of the PCSK9 gene and its expression levels with coronary artery disease (CAD) risk in Egyptian patients with type 2 diabetes mellitus (T2DM). Subjects and Methods: A case-control study was performed on 112 lean subjects compared to 100 T2DM patients without CAD and 84 T2DM patients with CAD to investigate the relationships among PCSK9 expression levels, the E670G (rs505151) gene variant, lipid concentrations, and CAD risk in an Egyptian diabetic population. A restriction fragment length polymorphism-polymerase chain reaction (PCR) assay was used to assess the gene polymorphism, and PCSK9 mRNA expression was determined by quantitative real-time PCR. Results: The prevalence of the E670G (rs505151) AG genotype in diabetics with CAD was significantly greater than the other two groups. The PCSK9 gene expression levels in diabetics with CAD were significantly greater than the other two groups. G allele carriers (AG+GG) had a higher relative PCSK9 expression than A allele carriers. Conclusion: PCSK9 relative expression levels and the E670G (rs505151) AG genotype are CAD risk factors among Egyptian diabetics and are linked positively to the atherogenic index of plasma.

Associations of galectin-3 expression and LGALS-3 (rs4652) gene variant with coronary artery disease risk in diabetics

Background

Galectin-3 protein encoded by lectin galactoside-binding soluble-3 (LGALS-3) gene is an important genetic factor in type 2 diabetes mellitus (T2DM) and its cardiovascular obstacles in various populations. We aimed to elicit the pro-inflammatory effect of galectin-3 as determined by interleukin-6 (IL-6) serum levels and to explore the relationship between galectin-3 (LGALS-3 rs4652) gene variant and its expression levels with coronary artery disease (CAD) risk among T2DM Egyptian patients.

Methods

112 lean subjects were compared to 100 T2DM without CAD and 84 T2DM with CAD. A tetra-primer amplification refractory mutation system polymerase chain reaction was used to test LGALS-3 (rs4652), and galectin3 expression was tested with a quantitative real-time polymerase chain reaction. Serum IL-6 was measured using an enzyme-linked immunosorbent assay.

Results

We found that the prevalence of LGALS-3 (rs4652) AC genotype and galectin-3 gene expression levels in T2DM with CAD were significantly higher than the additional 2 groups and were correlated positively to IL-6 circulating levels. Also, the C allele carriers (AC+CC) had significantly higher relative Galectin-3 expression levels compared to the A allele carriers (AA).

Conclusions

We concluded that galectin-3 expression levels and LGALS-3 (rs4652) AC genotype were coronary artery disease risk factors in people with type two diabetes among an Egyptian sample.

Aberrant Methylation of Aging-Related Genes in Asthma

Background: Asthma is a complex pulmonary inflammatory disease which is common among older adults. Aging-related alterations have also been found in structural cells and immune cells of asthma patients. Nonetheless, the underlying mechanism by which differenced aging-related gene contributes to asthma pathology remains unclear. Of note, DNA methylation (DNAm) has been proven to play a critical mechanism for age-related gene expression changes. However, the methylation changes of aging-related genes in asthma patients are still obscure.

Methods: First, changes in DNAm and gene expression were detected with multiple targeted bisulfite enrichment sequencing (MethTarget) and qPCR in peripheral blood of 51 healthy controls (HCs) and 55 asthmatic patients. Second, the correlation between the DNAm levels of specific altered CpG sites and the pulmonary function indicators of asthma patients was evaluated. Last, the receiver operator characteristic (ROC) curve and principal component analysis (PCA) were used to identify the feasibility of the candidate CpG sites as biomarkers for asthma.

Results: Compared with HCs, there was a differential mRNA expression for nine aging-related genes in peripheral blood of asthma patients. Besides, the methylation levels of the nine aging-related genes were also altered in asthma patients, and a total of 68 CpG sites were associated with the severity of asthma. Notably, 9 of the 68 CpG sites were significantly associated with pulmonary function parameters. Moreover, ROC curve and PCA analysis showed that the candidate differential methylation sites (DMSs) can be used as potential biomarkers for asthma.

Conclusions: In summary, this study confirmed the differentially expressed mRNA and aberrant DNAm level of aging-related genes in asthma patients. DMSs are associated with the clinical evaluation indicators of asthma, which indicate the involvement of aging-related genes in the pathogenesis of asthma and provide some new possible biomarkers for asthma.

Advances in sulfur mustard-induced DNA adducts: Characterization and detection

Sulfur mustard (SM) is a blister chemical warfare agent with severe cytotoxicity and genotoxicity. It can extensively alkylate important macromolecules in organisms, such as proteins, DNA, and lipids, and produce a series of metabolites, among which the characteristic ones can be used as biomarkers. The exact toxicological mechanisms of SM remain unclear but mainly involve the DNA lesions induced by alkylation and oxidative stress caused by glutathione depletion. Various methods have been used to analyze DNA damage caused by SM. Among these methods, liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology stands out and makes it possible to observe damage in view of biomarkers induced by SM. Sample preparation is critical for detection by LC-MS/MS and mainly includes DNA isolation, adduct hydrolysis, and adduct purification. Moreover, optimization of chromatographic conditions, selection of MS transitions, and quantitative strategies are also essential. SM-DNA adducts are generally considered to be N⁷-HETEG, O⁶-HETEG, N⁷-BisG, and N³-HETEA. This article proposes some other possibilities of SM-DNA adducts for the identification of SM genotoxicity.

Association between erythema nodosum/ erythema induratum of Bazin and Mycobacterium tuberculosis infection in Koreans

BACKGROUND

Erythema nodosum and erythema induratum of Bazin are similar inflammatory diseases of the lower extremities. These are clinically distinguishable entities, though overlap can occur. Both diseases are reported to be related to Mycobacterium tuberculosis infection, but it is very difficult to identify Mycobacterium tuberculosis in skin lesions.

AIM

This study aimed to develop a new nested polymerase chain reaction targeting the IS6110 insertion sequence of M. tuberculosis to improve the M. tuberculosis detection rate in skin lesions of erythema nodosum or erythema induratum of Bazin.

METHODS

From May 2016 to Jan 2018, 14 patients with clinically suspicious erythema nodosum or erythema induratum were enrolled in the study. Two cases were classified as erythema nodosum and 12 as erythema induratum. Individual patients were subjected to a 4-mm punch biopsy, and their venous whole blood was sampled immediately after diagnosis.

RESULTS

Eight patients were tested for M. tuberculosis using QuantiFERON, of which seven (87.5%) were positive. IS6110-nested polymerase chain reaction on all 14 patients identified 11 (78.6%) positive cases. Four of the eight (50%) individuals tested with QuantiFERON were also positive in the IS6110 nested polymerase chain reaction. The difference between the outcomes of the QuantiFERON and the IS6110-nested polymerase chain reaction tests was not statistically significant. There was also no significant agreement between the results of both assays. Sequencing the IS6110-nested polymerase chain reaction products showed a 97%-100% nucleotide sequence identity with the H37Rv genome.

CONCLUSION

It is important to test for tuberculosis in patients with multiple tender subcutaneous nodules on their lower extremities in high-burden tuberculosis countries like Korea.

LIMITATIONS

We need to register more suspicious patients to verify the association between erythema nodosum/erythema induratum of Bazin and M. tuberculosis. Furthermore, it is necessary to improve the more sensitive polymerase chain reaction technique to identify M. tuberculosis directly in cutaneous lesions.

Identification of lncRNA-Protein Interactions by CLIP and RNA Pull-Down Assays

The emerging data indicates that long noncoding RNAs (lncRNAs) are involved in fundamental biological processes, and their deregulation may lead to oncogenesis and other diseases. LncRNA fulfil its biological functions at least in part by interacting with distinctive proteins. Here, we described two methods to identify the direct or indirect interactions between lncRNA and proteins: cross-linking and immunoprecipitation (CLIP) and RNA pull-down assay. CLIP methods enable yield a list of lncRNAs that directly interact target protein in living cells, whereas immunoprecipitation of biotin-labeled RNA (RNA pull-down) assay represents a method for identification of proteins that directly and indirectly bind with a particular target lncRNA of interest.

The Utilization of Linear Polylysine Coupled with Mechanic Forces to Extract Microbial DNA from Different Matrices

Molecular approaches are powerful tools that are used for medical or environmental diagnoses. However, the main limitations of such a tools are that they extract low levels of DNA and they do not remove the inhibitors of polymerase chain reaction (PCR). Although the use of polycation to complex and purify DNA has been described in the literature, elution often requires a high ionic strength or pH levels not compatible with molecular analyses. In this paper, we described a new process that is based on the complexation of DNA with linear polylysine, followed by capturing the complex by a cation exchange resin. The originality of the process consisted of using mechanic force to elute DNA from the complex. The extraction method showed several advantages when compared to existing methods, such as being compatible with pH levels that range from 5 to 11, as well as high levels of DNA recovery and elimination of PCR inhibitors from complex samples. This method was successfully applied to different types of samples, such as environmental samples, beverage samples, and medical samples. Furthermore, it was proven to be a good solution for removing PCR inhibitors and assuring good DNA recovery yield.

Simultaneous cell lysis and DNA extraction from whole blood using magnetic ionic liquids

Conventional DNA sample preparation methods involve tedious sample handling steps that require numerous inhibitors of the polymerase chain reaction (PCR) and instrumentation to implement. These disadvantages limit the applicability of conventional cell lysis and DNA extraction methods in high-throughput applications, particularly in forensics and clinical laboratories. To overcome these drawbacks, a series of nine hydrophobic magnetic ionic liquids (MILs) previously shown to preconcentrate DNA were explored as cell lysis reagents. The MILs were found to lyse white blood cells from whole blood, 2-fold diluted blood, and dry blood samples while simultaneously extracting human genomic DNA. The identity of metal ion incorporated within the MIL appears to cause hemolysis while the cationic component further reduces the cell's integrity. Over 500 pg of human genomic DNA was isolated from 50 μL of whole blood using the trioctylbenzylammonium tris(hexafluoroacetylaceto)nickelate(II) ([N_8,8,8,Bz⁺][Ni(hfacac)₃^-]) MIL, and 800 pg DNA was isolated from a dry blood samples using the trihexyl(tetradecyl)phosphonium tris(phenyltrifluoroacetylaceto)nickelate(II) ([P_6,6,6,14⁺][Ni(Phfacac)₃^-]) MIL following a 1-min vortex step. A rapid, one-step cell lysis and DNA extraction from blood is ideal for settings that seek high-throughput analysis while minimizing the potential for contamination.Graphical abstract.

DNA methylation down-regulates integrin β4 expression in asthmatic airway epithelial cells

BACKGROUND

Integrin β4 (ITGB4) is a hemi-desmosome protein which is downregulated in the airway epithelial cells of asthma patients. The proximal promoters and exons of ITGB4 contain CpG islands or multiple CpG sites both in human and mice, which indicated the possible methylation regulation of ITGB4 in airway epithelial cells.

OBJECTIVE

We sought to unveil that DNA methylation regulates the decreased ITGB4 during the pathogenesis of asthma.

METHODS

Mice were exposed to house dust mite (HDM) extracts to construct an asthma model. 5-Aza-2'-deoxycytidine (5-AZA) or dexamethasone (DEX) were added in the last two weeks. Besides, the primary human bronchial epithelial (HBE) cells were incubated for the detection of ITGB4 expression and methylation status after HDM stress. Furthermore, DNA methylation of ITGB4 in peripheral blood was measured in asthma patients. Logistic regression was employed to evaluate the association between methylation sites and asthma patients' ages in the control of potential confounders. Moreover, the correlations between differentially methylated sites (DMSs) and clinical parameters in asthma patients were assessed. Finally, the ability of candidate DMSs to predict asthma was evaluated by receiver operating characteristic (ROC) analysis and principal component analysis (PCA).

RESULTS

We found that in HDM-stressed asthma model, DNA methylation regulated the reduced ITGB4 expression in airway epithelial cells. Moreover, alteration in the specific CpG sites (chr17:73717720 and chr17:73717636) of ITGB4 may regulate ITGB4 expression and further may be associated with the clinically phenotypic of asthma. The specific DMSs of ITGB4 in peripheral blood can distinguish asthma patients from healthy controls (HCs) effectively.

CONCLUSIONS AND CLINICAL RELEVANCE

This study confirmed that DNA methylation regulates the decreased expression of ITGB4 in the airway epithelial cells of asthma patients. These results supply some useful insights to the mechanism of the decreased ITGB4 in asthmatic airway epithelial and provide possible targets for early prediction and screening of asthma.

Parallel DNA Extraction From Whole Blood for Rapid Sample Generation in Genetic Epidemiological Studies

Large-scale genetic epidemiological studies require high-quality analysis of samples such as blood or saliva from multiple patients, which is challenging at the point of care. To expand these studies’ impact, minimal sample storage time and less complex extraction of a substantial quantity and good purity of DNA or RNA for downstream applications are necessary. Here, a simple microfluidics-based system that performs genomic DNA (gDNA) extraction from whole blood was developed. In this system, a mixture of blood lysate, paramagnetic beads, and binding buffer are first placed into the input well. Then, the gDNA-bound paramagnetic beads are pulled using a magnet through a central channel containing a wash buffer to the output well, which contains elution buffer. The gDNA is eluted at 55°C off the chip. The 40-minute microfluidic protocol extracts gDNA from six samples simultaneously and requires an input of 4 μL of diluted blood and a total reagent volume of 75 μL per reaction. Techniques including quantitative PCR (qPCR) and spectrofluorimetry were used to test the purity and quantity of gDNA eluted from the chip following extraction. Bead transport and molecular diffusional analysis showed that an input of less than 4 ng of gDNA (∼667 white blood cells) is optimal for on-chip extraction. There was no observable transport of inhibitors into the eluate that would greatly affect qPCR, and a sample was successfully prepared for next-generation sequencing (NGS). The microfluidics-based extraction of DNA from whole blood described here is paramount for future work in DNA-based point-of-care diagnostics and NGS library workflows.

Variable DNA methylation of aging-related genes is associated with male COPD

Background

Chronic obstructive pulmonary disease (COPD) is a chronic lung inflammatory disease which has a close relationship with aging. Genome-wide analysis reveals that DNA methylation markers vary obviously with age. DNA methylation variations in peripheral blood have the potential to be biomarkers for COPD. However, the specific DNA methylation of aging-related genes in the peripheral blood of COPD patients remains largely unknown.

Methods

Firstly, 9 aging-related differentially expressed genes (DEGs) in COPD patients were screened out from the 25 aging-related genes profile through a comprehensive screening strategy. Secondly, qPCR and multiple targeted bisulfite enrichment sequencing (MethTarget) were used to detect the mRNA level and DNA methylation level of the 9 differentially expressed genes in the peripheral blood of 60 control subjects and 45 COPD patients. The candidate functional CpG sites were selected on the basis of the regulation ability of the target gene expression. Thirdly, the correlation was evaluated between the DNA methylation level of the key CpG sites and the clinical parameters of COPD patients, including forced expiratory volume in one second (FEV1), forced expiratory volume in one second as percentage of predicted volume (FEV1%), forced expiratory volume/ forced vital capacity (FEV/FVC), modified British medical research council (mMRC) score, acute exacerbation frequency and the situation of frequent of acute aggravation (CAT) score. Lastly, differentially methylated CpG sites unrelated to smoking were also determined in COPD patients.

Results

Of the 9 differentially expressed aging-related genes, the mRNA expression of 8 genes were detected to be significantly down-regulated in COPD group, compared with control group. Meanwhile, the methylated level of all aging-related genes was changed in COPD group containing 219 COPD-related CpG sites in total. Notably, 27 CpG sites of FOXO3 gene showed a lower False Discovery Rate (FDR) and higher methylation difference values. Also, some variable DNA methylation is associated with the severity of COPD. Additionally, of the 219 COPD-related CpG sites, 147 CpG sites were not related to smoking.

Conclusion

These results identified that the mRNA expression and DNA methylation level of aging-related genes were changed in male COPD patients, which provides a molecular link between aging and COPD. The identified CpG markers are associated with the severity of COPD and provide new insights into the prediction and identification of COPD.

Merkel cell polyomavirus DNA sequences in the blood of healthy population of Pakistan

Aim: This study aimed at detecting and quantifying Merkel cell polyomavirus (MCPyV) viral loads in the peripheral blood of healthy Pakistani individuals. Patients & methods: A total of 221 whole blood samples obtained from healthy individuals were examined by qPCR. Results & conclusion: MCPyV was detected in the peripheral blood of 31.2% healthy individuals. The rate of MCPyV positivity decreased from young (36%), to middle (33.7%) and elder (25.3%) age groups. Our data revealed higher prevalence of MCPyV in women (43.93%) than men (25.80%). The MCPyV viral load was calculated in the range of 0.06 -11 copies/ng of isolated DNA. The MCPyV viral load increased from young (median = 3.35) to elder (median = 5.66) age groups. The MCPyV circulate at a higher frequency by residing dormant in certain blood cells, which might act as potential vehicles for the spread of MCPyV infection among general population.

Novel extraction of high quality genomic DNA from frozen bovine blood samples by using detergent method

DNA is the prerequisite for life’s inception that transfers hereditary information, past several years; various types of commercial kits are made available which vary depending on the type of the biological sample being used. The present study is focused on developing an improvised methodology for the isolation of genomic DNA from stored bovine blood samples. DNA was isolated by using the conventional Phenol: Chloroform: Isoamyl alcohol (PCI) method and Detergent method. The aim of the study was to make a comparative analysis and evaluation of these two methods to identify the one that gives a superior quality and quantity of genomic DNA. Total (n=48) each duplicate blood samples from three different buffalo(Bubalus bubalis) breeds Banni, Surti, Murrah, three zebu cattle (Bos indicus) breeds Kankerj, Gir, Sahiwal were collected from the jugular vein. The quantity, purity of the genomic DNA was assessed based on the total DNA yield, purity ratios, spectral profile, agarose gel electrophoresis analysis and polymerase chain reaction amplification of MC1R gene product without any inhibitors. The results of our study suggest that detergent method is also suitable for extraction of genomic DNA from the bovine blood and results were significant (*P>0.05). The total mean yield was found to be 329.05±11 μg/5ml for all six breeds while the PCI method was employed. The total mean yield of the gDNA for all six breeds was 406.6±43 μg/5ml of blood when the detergent method was used. One way ANOVA test showed that the total DNA yield varied depending on the isolation method used. The DNA yield obtained from the DG method was (***P< 0.001) significant as compared to the PCI method (**P<0.01).

Measuring coverage and accuracy of whole-exome sequencing in clinical context

PURPOSE

To evaluate the coverage and accuracy of whole-exome sequencing (WES) across vendors.

METHODS

Blood samples from three trios underwent WES at three vendors. Relative performance of the three WES services was measured for breadth and depth of coverage. The false-negative rates (FNRs) were estimated using the segregation pattern within each trio.

RESULTS

Mean depth of coverage for all genes was 189.0, 124.9, and 38.3 for the three vendor services. Fifty-five of the American College of Medical Genetics and Genomics 56 genes, but only 56 of 63 pharmacogenes, were 100% covered at 10 × in at least one of the nine individuals for all vendors; however, there was substantial interindividual variability. For the two vendors with mean depth of coverage >120 ×, analytic positive predictive values (aPPVs) exceeded 99.1% for single-nucleotide variants and homozygous indels, and sensitivities were 98.9-99.9%; however, heterozygous indels showed lower accuracy and sensitivity. Among the trios, FNRs in the offspring were 0.07-0.62% at well-covered variants concordantly called in both parents.

CONCLUSION

The current standard of 120 × coverage for clinical WES may be insufficient for consistent breadth of coverage across the exome. Ordering clinicians and researchers would benefit from vendors' reports that estimate sensitivity and aPPV, including depth of coverage across the exome.

Value of VKORC1 (-1639G>A) rs9923231 genotyping in predicting warfarin dose: A replication study in South Indian population

OBJECTIVE

Warfarin is the most commonly prescribed oral anticoagulant, although having a narrow therapeutic index and wide interindividual variability. The aim of this study was to replicate the utility of VKORC1 (-1639G>A) rs9923231 genotyping in predicting the mean daily dose and to evaluate its ability to categorize warfarin-treated patients to high-, intermediate-, or low-dose categories in the South Indian population.

MATERIALS AND METHODS

A cohort of 222 warfarin-treated patients was genotyped using restriction fragment length polymorphism method. The influence of the rs9923231 polymorphism on the variations in the mean daily dose was compared using one-way analysis of variance and linear regression analysis. Discriminatory ability of the rs9923231 polymorphism to group the patients into ordered dose categories was assessed by estimating the proportional odds ratios using the ordered logit regression analysis.

RESULTS

The frequency of AA genotype and A allele in the study sample was found to be 1.8% and 9.23%, respectively, which was similar to reports from other South Indian populations. The mean daily dose required to achieve the optimum international normalized ratio was significantly lower in AA homozygous genotype carriers (3.99 ± 1.67 mg/day) and GA heterozygous (4.26 ± 1.57 mg/day) compared to the GG genotype carriers (5.51 ± 2.13 mg/day), p = 0.003. The A allele carriers (GA+AA genotypes) had a 3.23 higher odds of being grouped as a low-dose requiring category compared to non-carriers (95% CI 1.49-6.98, p = 0.003).

CONCLUSIONS

These preliminary results strongly support the use of VKORC1 (-1639G>A) rs9923231 polymorphism for genetically guided initial warfarin dosing in South Indian patients with heart valve replacements.

Impact of DNA extraction method and targeted 16S-rRNA hypervariable region on oral microbiota profiling

Amplification and sequencing of 16S amplicons are widely used for profiling the structure of oral microbiota. However, it remains not clear whether and to what degree DNA extraction and targeted 16S rRNA hypervariable regions influence the analysis. Based on a mock community consisting of five oral bacterial species in equal abundance, we compared the 16S amplicon sequencing results on the Illumina MiSeq platform from six frequently employed DNA extraction procedures and three pairs of widely used 16S rRNA hypervariable primers targeting different 16S rRNA regions. Technical reproducibility of selected 16S regions was also assessed. DNA extraction method exerted considerable influence on the observed bacterial diversity while hypervariable regions had a relatively minor effect. Protocols with beads added to the enzyme-mediated DNA extraction reaction produced more accurate bacterial community structure than those without either beads or enzymes. Hypervariable regions targeting V3-V4 and V4-V5 seemed to produce more reproducible results than V1-V3. Neither sequencing batch nor change of operator affected the reproducibility of bacterial diversity profiles. Therefore, DNA extraction strategy and 16S rDNA hypervariable regions both influenced the results of oral microbiota biodiversity profiling, thus should be carefully considered in study design and data interpretation.

Tetrandrine alleviates symptoms of rheumatoid arthritis in rats by regulating the expression of cyclooxygenase-2 and inflammatory factors

The present study aimed to construct a rat model of rheumatoid arthritis (RA) to evaluate changes in pathology, the expression of inflammatory factors and regulation of signaling pathways. The protective effect of tetrandrine (Tet) on tissue lesions induced by RA was also investigated. A total of 60 Wistar rats (100-200 g) were randomly divided into six groups (n=10 per group), namely a blank (NC) group, model group, methotrexate (MTX) group (3 mg/kg body weight), high-dose Tet group (31.25 mg/kg body weight), medium-dose Tet group (18.75 mg/kg body weight) and low-dose Tet group (6.25 mg/kg body weight). A rat model of RA was induced via injection of 0.1 ml complete Freund's adjuvant into the right rear toe. Toe swelling rate, arthritis index and immune organ index were calculated. In addition, cyclooxygenase (COX)-2 expression at the mRNA and protein level in the peripheral blood mononuclear cells (PBMCs) of rats were determined by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. Serum concentrations of inflammatory factors were measured using enzyme-linked immunosorbent assays. It was observed that treatment with Tet alleviated the severity of rear toe swelling associated with RA in rats. Furthermore, Tet exerted anti-inflammatory and immunosuppressive effects in the rat model of RA. Tet also reduced the expression of COX-2 in PBMCs and lowered the concentrations of inflammatory factors in the serum of RA rats. The present data indicate that Tet may exert pharmacological effects in the treatment of RA. The mechanism of action of Tet may be associated with the regulation of inflammatory factors and the inhibition of immune organs.

Lack of association of mirSNP rs11174811 in AVPR1A gene with arterial blood pressure and hypertension in South Indian population

Epigenetic regulation of arterial blood pressure mediated through mirSNPs in renin-angiotensin aldosterone system (RAAS) genes is a less explored hypothesis. Recently, the mirSNP rs11174811 in the 3'UTR of the AVPR1A gene was associated with higher arterial blood pressure in a large study population from the Study of Myocardial Infarctions Leiden (SMILE). The aim of the present study was to replicate the association of mirSNP rs11174811 with blood pressure outcomes and hypertension in a south Indian population. Four hundred and fifteen hypertensive cases and 416 normotensive controls were genotyped using a 5' nuclease allelic discrimination assay. Logistic regression was used to test the association of mirSNP rs11174811 with the hypertension phenotype. Censored normal regression was used to test the association of the polymorphism with continuous blood pressure outcomes such as systolic and diastolic blood pressure. The mirSNP rs11174811 did not show any significant association with hypertension. The adjusted odds ratio was 1.02, with 95% CI of 0.72 to 1.45 (p = 0.909). The mean systolic and diastolic blood pressure values were not significantly different across the three genotypic groups, between hypertensives and normotensives, or when stratified by gender. Despite having a similar minor allele frequency (MAF) of 14.5% compared with the SMILE cohort, our results did not support an association of the mirSNP rs11174811 with the hypertension phenotype or with continuous blood pressure outcomes in the south Indian population.