Discover the most talked about and latest scientific content & concepts.

Concept: Genetic polymorphism


Genetic polymorphism is suggested to be associated with human physical performance. The angiotensin I-converting enzyme insertion/deletion (ACE I/D) polymorphism and the α-actinin-3 gene (ACTN3) R577X polymorphism have been most widely studied for such association analysis. However, the findings are frequently heterogeneous. We aim to summarize the associations of ACE I/D and ACTN3 R577X with sport performance by means of meta-analysis.

Concepts: Genetics, Allele, Chromosome, The Association, Polymorphism, Adaptation, Genetic polymorphism, Julian Huxley


OBJECTIVE: Disordered metabolism of estrogen is believed to play a significant role in endometrial carcinogenesis. Recently, a number of studies have been conducted to identify the role of estrogen-related gene polymorphism in endometrial cancer risk, generating conflicting conclusions. This meta-analysis aimed to assess the association between genetic polymorphisms involving estrogen metabolic enzymes and endometrial cancer risk. METHODS: A systematic search of 6 databases was conducted. Fourteen studies on the association of COMT (catechol-O-methyltransferase) Val158Met, CYP1B1 Leu432Val, and CYP1B1 Asn453Ser polymorphisms with endometrial cancer risk were identified, enrolling a total of 4283 cancer cases and 7094 controls. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the relationship. RESULTS: In CYP1B1 Leu432Val( rs1056836) analysis, the heterozygous genotype (CG) demonstrated an increased risk for endometrial cancer (Val/Leu vs Leu/Leu: pooled OR, 1.11; 95% CI, 1.01-1.23; P = 0.039; I = 10.5%; (Val/Val +Val/Leu) vs Leu/Leu: pooled OR, 1.19; 95% CI, 1.03-1.38; P = 0.017; I = 54.7%). As for CYP1B1 Asn453Ser(rs1800440) polymorphism, a decreased risk was observed in G allele compared with A allele (Ser vs Asn: pooled OR, 0.82; 95% CI, 0.72-0.94; P = 0.005; I = 0.0%), and heterozygous genotype also showed a decreased risk compared with normal genotype (Ser/Asn vs Asn/Asn: pooled OR, 0.81; 95% CI, 0.69-0.95; P = 0.011; I = 0.0%). As for COMT Val158Met (rs4680) polymorphism, the heterogeneous genotype showed a decreased risk for endometrial cancer compared with the common homogenous genotype in a fixed-effect model in Asian population (Met/Val vs Val/Val: pooled OR, 0.83; 95% CI, 0.70-0.98; P = 0.033; I = 29.2%), whereas no positive results are found in other subgroups or models. CONCLUSIONS: COMT Val158Met was seen to show a decreased risk for endometrial cancer in Asian population. CYP1B1 Leu432Val and Asn453Ser polymorphisms demonstrated an increased and decreased risk for endometrial cancer, respectively. Further large and comprehensive studies in various populations with more detailed individual data are needed to confirm our findings.

Concepts: Genetics, Genotype, Allele, Estrogen, Cytochrome P450, Endometrial cancer, Polymorphism, Genetic polymorphism


The androgen receptor (AR) gene polymorphism in humans is linked to aggression and may also be linked to reproduction. Here we report associations between AR gene polymorphism and aggression and reproduction in two small-scale societies in northern Tanzania (Africa)-the Hadza (monogamous foragers) and the Datoga (polygynous pastoralists). We secured self-reports of aggression and assessed genetic polymorphism of the number of CAG repeats for the AR gene for 210 Hadza men and 229 Datoga men (aged 17-70 years). We conducted structural equation modeling to identify links between AR gene polymorphism, aggression, and number of children born, and included age and ethnicity as covariates. Fewer AR CAG repeats predicted greater aggression, and Datoga men reported more aggression than did Hadza men. In addition, aggression mediated the identified negative relationship between CAG repeats and number of children born.

Concepts: Genetics, Allele, Chromosome, Tanzania, Androgen receptor, Genetic polymorphism, Julian Huxley


Limited information is available when it comes to the impact of genetic on Calcific Aortic Stenosis (CAS). Apolipoprotein B (apoB) is a key component in lipid metabolism and plays an important role in the dynamic equilibrium of cholesterol. We performed a case-control study to explore the association of apoB genetic polymorphisms with CAS in Chinese subjects, in Xinjiang, China.

Concepts: Genetics, Allele, Apolipoprotein B, Apolipoprotein, Polymorphism, Adaptation, Genetic polymorphism


Epidemiologic studies have suggested that parental occupations, pesticide use, environmental factors, and genetic polymorphism are involved in the etiology of childhood acute leukemia (CAL). In total, 116 cases of CAL and 162 controls were recruited and submitted to blood drawing to assess the presence of genetic polymorphisms. Parental occupations, pesticides exposure, and other potential determinants were investigated. Increased risk for CAL was associated with prenatal maternal use of insecticides/rodenticides (odds ratio [OR]=1.87; 95% confidence intervals [CI], 1.04-3.33), with subjects living <100 m from pesticide-treated fields (OR=3.21; 95% CI, 1.37-7.53) and with a paternal occupation as traffic warden/policeman (OR=4.02; 95% CI, 1.63-9.87). Associations were found between CAL and genetic polymorphism of CYP2D6*4 for homozygous alleles (mutant type/mutant type: OR=6.39; 95% CI, 1.17-34.66). In conclusion, despite the small sample size, maternal prenatal exposure to pesticides, paternal occupation as a traffic warden/police officer, and CYP2D6*4 polymorphism could play a role in the etiology of CAL.

Concepts: Genetics, Epidemiology, Allele, Sample size, Pesticide, Polymorphism, Adaptation, Genetic polymorphism


Over 30 years ago, black Africans from Kenya and Ghana were shown to metabolize acetaminophen faster by glucuronidation and slower by oxidation compared with white Scottish Europeans. The objectives of this study were to determine whether similar differences exist between African-Americans and European-Americans, and to identify genetic polymorphisms that could explain these potential differences. Acetaminophen plasma pharmacokinetics and partial urinary metabolite clearances via glucuronidation, sulfation, and oxidation were determined in healthy African-Americans (18 men, 23 women) and European-Americans (34 men, 20 women) following a one-gram oral dose. There were no differences in acetaminophen total plasma, glucuronidation, or sulfation clearance values between African-Americans and European-Americans. However, median oxidation clearance was 37% lower in African-Americans versus European-Americans (0.57 versus 0.90 mL/min/kg; P=0.0001). Although acetaminophen total or metabolite clearance values were not different between genders, shorter plasma half-life values (by 11 to 14%; P<0.01) were observed for acetaminophen, acetaminophen glucuronide, and acetaminophen sulfate in women versus men. The UGT2B15*2 polymorphism was associated with variant allele number proportional reductions in acetaminophen total clearance (by 15 to 27%; P<0.001) and glucuronidation partial clearance (by 23 to 48%; P<0.001). UGT2B15 *2/*2 genotype subjects also showed higher acetaminophen protein-adduct concentrations than *1/*2 (by 42%; P=0.003) and *1/*1 (by 41%; P=0.003) individuals. Finally, CYP2E1 *1D/*1D genotype African-Americans had lower oxidation clearance than *1C/*1D (by 42%; P=0.041) and *1C/*1C (by 44%; P=0.048) African-Americans. Consequently, African-Americans oxidize acetaminophen more slowly than European-Americans, which may be partially explained by the CYP2E1*1D polymorphism. UGT2B15*2 influences acetaminophen pharmacokinetics in both African-Americans and European-Americans.

Concepts: Genetics, Allele, Polymorphism, Adaptation, Genetic polymorphism


Breast cancer is the most common type of cancer among females. Genetic polymorphisms might have a role in carcinogenesis. The aim of this study was to determine whether C to T base substitution within TaqI Vitamin D receptor (VDR) gene (rs731236) in exon 9 was a risk factor among patients with breast cancer.

Concepts: DNA, Vitamin D, Genetics, Cancer, Breast cancer, Allele, Chromosome, Genetic polymorphism


Little evidence is available regarding the impact of genetic polymorphisms on the risk of thromboembolic stroke in patients with atrial fibrillation (AF). An increasing body of evidence demonstrates that inflammatory responses play an important role in the pathophysiology of AF.

Concepts: Inflammation, Gene, Genetics, Allele, Chromosome, Stroke, Atrial fibrillation, Genetic polymorphism


To establish a physiologically-based pharmacokinetic (PBPK) model for analyzing the factors associated with side effects of irinotecan by using a computer-based virtual clinical study (VCS) because many controversial associations between various genetic polymorphisms and side effects of irinotecan have been reported.

Concepts: Pharmacology, Clinical trial, Allele, Effectiveness, Pharmaceutical industry, Polymorphism, Adaptation, Genetic polymorphism


Rocuronium (ROC) is a neuromuscular blocker mainly eliminated by biliary excretion dependent on organic anion transporting polypeptide 1A2 (OATP1A2) hepatocellular uptake. However, the influence of SLCO1A2 (gene encoding OATP1A2) genetic polymorphism on ROC pharmacokinetics was never described before. The objective of this work was to evaluate the influence of genetic polymorphisms of SLCO1A2 on the pharmacokinetics of rocuronium (ROC).

Concepts: Genetics, Allele, Chromosome, Polymorphism, Adaptation, Genetic polymorphism