Apolipoprotein E Polymorphism and Alzheimer’s Risk in Kashmiri Population

Background: Although the cause of Alzheimer's disease is unknown, most experts feel that the disease is caused by a combination of circumstances rather than a single cause. Age, gene polymorphism, diabetes, and other conditions are all risk factors for Alzheimer's disease. Given the importance of gene polymorphism in different diseases, we intended to find out the association of APOE gene polymorphism with Alzheimer's risk in the Kashmiri population. Method: Out of 300 patients who were referred to the memory clinic of the hospital, to evaluate the probable relation of APOE gene variation in Alzheimer's disease, we conducted the study on 59 clinically confirmed Alzheimer's patients and 52 age and ethnicity-matched healthy controls found in a community survey. Results: Our data revealed a statistically significant association of ε4 variant genotype of the APOE gene with AD susceptibility in the Kashmiri population. Conclusions: The current study's findings provided insight into the role of APOE polymorphisms in Alzheimer's disease susceptibility. The identified susceptibility variant may become a marker genotype for AD.

The Association of ADRA2A Genotype with Dexmedetomidine Dosage in Pediatric Patients

Background: Critically ill children in the pediatric intensive care unit (PICU) often require sedation with dexmedetomidine, an α2-adrenergic receptor (ADRA2A) agonist. In adults, evidence suggests an ADRA2A polymorphism (rs1800544) modulates the dexmedetomidine response. We hypothesize that pediatric patients with at least one wild-type allele (GG and GC) will require larger dexmedetomidine doses and a longer time to effective dose than patients with a variant genotype (CC). Methods: This study was approved by the institutional review board (IRB). Patients in the PICU, 1 week through 25 years of age, and sedated with dexmedetomidine for ≥ 2 days were approached for enrollment. Genomic DNA was extracted from blood or saliva before genotyping for rs1800544 with a custom designed TaqMan® Assay on the QuantStudio 12K Flex platform. Patient genotype was determined using TaqMan® Genotyper software. Patient data were collected from the electronic medical record. Results: Sixty-five patients were enrolled and genotyped. Twenty-six patients were homozygous variant (CC), 27 heterozygous (GC), and 12 wildtype (GG) for rs1800544. The maximum dose (mcg/kg/hr) was 0.75 ± 0.31, and 0.78 ± 0.32, in patients with and without a G allele, respectively (p=0.65). The mean doses were 0.59 ± 0.22 and 0.58 ± 0.24 in patients with and without a G allele, respectively (p=0.85). The time to effective dose (hrs) was 5.8 ± 12.0 for patients with a G allele and 4.0 ± 8.2 for patients with no G allele (p=0.74). Conclusion: Our hypothesis that the CC genotype would require lower doses of dexmedetomidine was not confirmed. Patients without a G allele required lower dexmedetomidine dosage and a longer time to achieve an effective dose, but these findings were not significant. This could be due to the small sample size or clinical factors that affect pediatric sedation. An adequately powered study could determine the association of ADRA2A genotype with dexmedetomidine.

Association of Gem-associated protein 4 gene polymorphisms with the risk of colorectal cancer in the Polish population

Aim: Gem-associated protein 4 (GEMIN4), a member of the GEMIN gene family, is a key compound of the regulating factors responsible for miRNA biogenesis. Genetic variability within this gene can alter the risk for development of colorectal cancer (CRC) as was shown for other genes involved in miRNA biogenesis. Therefore, presented study was intended to identify genetic variants of three single nucleotide polymorphisms (SNPs) in the GEMIN4 gene (rs1062923, rs2740348 and rs910925) and their relationship with CRC. Methods: The study comprised 203 patients and 179 age and sex matched controls. Genotyping of GEMIN4 gene variants was done using Taqman® assay. The association of GEMIN4 variants with CRC was done by odds ratio analysis. Haplotype analysis was done to see the combined effect of studied variants on CRC. Results: Patients carrying all variant genotypes for GEMIN4 rs1062923 (odds ratio [OR]= 0.205; 95% confidence interval [CI]= 0.1034-0.4065 for CC variant and [OR] = 0.1436; [CI] = 0.0869-0.2373 for CT variant, respectively) and GEMIN4 rs2740348 (odds ratio [OR]= 0.4498; 95% confidence interval [CI]= 0.2342-0.8637for CC variant and [OR] = 0.3986; [CI] = 0.2043-0.7776 for CG variant, respectively) showed significant association in lower occurrence of cancer, whereas in case of GEMIN4 G/C rs910925 variant genotype, no significance correlation was found. Conclusions: Our study gives a substantive support for the association between the GEMIN4 gene variants/miRNA biogenesis and CRC risk.

Genome-wide Identification and Analysis of Splicing QTLs in Multiple Sclerosis by RNA-Seq Data

Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory demyelinating lesions in the central nervous system. Recently, the dysregulation of alternative splicing (AS) in the brain has been found to significantly influence the progression of MS. Moreover, previous studies demonstrate that many MS-related variants in the genome act as the important regulation factors of AS events and contribute to the pathogenesis of MS. However, by far, no genome-wide research about the effect of genomic variants on AS events in MS has been reported. Here, we first implemented a strategy to obtain genomic variant genotype and AS isoform average percentage spliced-in values from RNA-seq data of 142 individuals (51 MS patients and 91 controls). Then, combing the two sets of data, we performed a cis-splicing quantitative trait loci (sQTLs) analysis to identify the cis-acting loci and the affected differential AS events in MS and further explored the characteristics of these cis-sQTLs. Finally, the weighted gene coexpression network and gene set enrichment analyses were used to investigate gene interaction pattern and functions of the affected AS events in MS. In total, we identified 5835 variants affecting 672 differential AS events. The cis-sQTLs tend to be distributed in proximity of the gene transcription initiation site, and the intronic variants of them are more capable of regulating AS events. The retained intron AS events are more susceptible to influence of genome variants, and their functions are involved in protein kinase and phosphorylation modification. In summary, these findings provide an insight into the mechanism of MS.

Association of β-defensin 1 gene Polymorphism and dental caries susceptibility in Tamil Ethnicity

Dental caries is a multifactorial disease that affects a large proportion of the population with both genetic and environmental factors contributing to the disease. Even in healthy oral environmental conditions, some individuals are susceptible to dental caries due to potential genetic contribution. Antimicrobial peptides are expressed in oral cavity and play an important role against microbial colonization and form an important first line defense against cariogenic bacteria. In the present study, we attempt to identify genetic variants that would cause significant functional impact towards susceptibility to dental caries. We investigated single nucleotide polymorphisms (SNPs) of beta-defensin 1 (DEFB1) as predictors of dental caries in tamil ethnic population. A total of 120 subjects were recruited for this study, which included 60 dental caries patients (DMFT>5) and 60 healthy controls (DMFT=0). Three SNPs of 5’UTR regulatory elements of DEFB1 were genotyped by PCR followed by Sanger sequencing. The genotypes associated with susceptibility to caries were found to be significant between rs11362 (p=.025, odds ratio = 3.72, 95% confidence interval (CI) = 1.289-10.742), rs1799946 (p=.023, odds ratio=4.32, 95% CI = 1.33-14.028) gene polymorphisms and risk of dental caries (DMFT>5) in tamil ethnicity. The variant genotype GG of rs1800972 polymorphism was found to be high in cases than controls but was not significant (p=0.136). Our data suggested that β-defensin 1 polymorphisms play a role in the susceptibility to dental caries.

Prospective and detailed behavioral phenotyping in DDX3X syndrome

Background DDX3X syndrome is a recently identified genetic disorder that accounts for 1–3% of cases of unexplained developmental delay and/or intellectual disability (ID) in females, and is associated with motor and language delays, and autism spectrum disorder (ASD). To date, the published phenotypic characterization of this syndrome has primarily relied on medical record review; in addition, the behavioral dimensions of the syndrome have not been fully explored. Methods We carried out multi-day, prospective, detailed phenotyping of DDX3X syndrome in 14 females and 1 male, focusing on behavioral, psychological, and neurological measures. Three participants in this cohort were previously reported with limited phenotype information and were re-evaluated for this study. We compared results against population norms and contrasted phenotypes between individuals harboring either (1) protein-truncating variants or (2) missense variants or in-frame deletions. Results Eighty percent (80%) of individuals met criteria for ID, 60% for ASD and 53% for attention-deficit/hyperactivity disorder (ADHD). Motor and language delays were common as were sensory processing abnormalities. The cohort included 5 missense, 3 intronic/splice-site, 2 nonsense, 2 frameshift, 2 in-frame deletions, and one initiation codon variant. Genotype–phenotype correlations indicated that, on average, missense variants/in-frame deletions were associated with more severe language, motor, and adaptive deficits in comparison to protein-truncating variants. Limitations Sample size is modest, however, DDX3X syndrome is a rare and underdiagnosed disorder. Conclusion This study, representing a first, prospective, detailed characterization of DDX3X syndrome, extends our understanding of the neurobehavioral phenotype. Gold-standard diagnostic approaches demonstrated high rates of ID, ASD, and ADHD. In addition, sensory deficits were observed to be a key part of the syndrome. Even with a modest sample, we observe evidence for genotype–phenotype correlations with missense variants/in-frame deletions generally associated with more severe phenotypes.

Association of NQO1Pro187Ser polymorphism with clinical outcomes and survival of lung cancer patients treated with platinum chemotherapy

Background: The study was carried out to evaluate the association of NQO1 P187S polymorphism in North Indian lung cancer (LC) patients. We determined the effect of this polymorphic variant on the survival of LC patients. Patients & methods/results: This case–control study comprised a total of 1100 subjects. The genotyping was carried out using PCR-RFLP and statistical analysis was carried out. The variant TT genotype exhibited 3.5-fold higher odds in subjects with stage III (p = 0.0006), fivefold higher odds of lymph-node invasion (p = 0.007) and an odd of <1 in case of metastasis (p = 0.0028). Patients possessing TT genotype and administered with paclitaxel, exhibited a poor survival (3.57 vs 12.20 months; hazard ratio = 7.95; p = 0.0098). Conclusion: These results suggest that NQO1 variant genotype was not found to modulate risk toward LC. However, the variant genotype was found to be strongly correlated with stage III LC, lymph node invasion and was found to be positively correlating with metastasis.

Association among extracellular superoxide dismutase genotype, plasma concentration, and comorbidity in the very old and centenarians

Superoxide dismutase 3 (SOD3), an antioxidant enzyme, is known as extracellular SOD (EC-SOD) because it is the predominant form in extracellular fluids. The diversity of plasma EC-SOD concentration is associated with the SOD3 p.R231G missense variant genotype. To clarify the association among SOD3 genotype, plasma EC-SOD concentration, and comorbidity in Oldest Old, we analyzed genome-wide associations with plasma EC-SOD concentration and associations between EC-SOD concentration and medical history classified by the SOD3 genotype in the Very Old (85–99 years old, n = 505) and Centenarians (over 100 years old, n = 595). The results revealed that SOD3 p.R231G was the most significant variant associated with plasma EC-SOD concentration. Although no significant difference was observed in medical histories between the SOD3 p.R231G variant non-carriers and carriers, higher EC-SOD concentration in plasma of SOD3 p.R231G variant non-carriers was associated with a high odds ratio for chronic kidney disease (OR = 2.70, 95% CI = 1.98–3.72) and low odds ratio for diabetes mellitus (DM) (OR = 0.61, 95% CI = 0.39–0.95). Comparison with 11 plasma biomarkers for age-related disease showed that plasma EC-SOD concentration correlated with adiponectin and estimated glomerular filtration rate with creatinine correction; therefore, we deduced that EC-SOD co-operates with adiponectin and possesses beneficial functions for DM in the Oldest Old.