The ß(2) -adrenergic receptor (ADRB2) is located on smooth muscle cells and is an important regulator of smooth muscle tone. The Thr164Ile polymorphism (rs1800888) in the ADRB2 gene is rare but has profound functional consequences on receptor function and could cause lifelong elevated smooth muscle tone. We tested the hypothesis that Thr164Ile is associated with increased blood pressure, increased frequency of hypertension and increased risk of cardiovascular disease (CVD).
A total of 66 750 individuals from two large Danish general population studies were genotyped, and 1943 Thr164Ile heterozygotes and 16 homozygotes were identified.
Thr164Ile genotype was associated with increased systolic and diastolic blood pressure in women (trend: P = 0.04 and 0.02): systolic and diastolic blood pressure increased by 5% and 2%, respectively, in female homozygotes compared with female noncarriers. All female Thr164Ile homozygotes had hypertension compared with 58% of female heterozygotes and 54% of female noncarriers (chi-square: P = 0.001). Female Thr164Ile homozygotes and heterozygotes had odds ratios for ischaemic heart disease (IHD) of 2.93 (0.56-15.5) and 1.28 (1.03-1.61), respectively, compared with female noncarriers (trend: P = 0.007). These differences were not observed in men. Furthermore, Gly16Arg (rs1042713) and Gln27Glu (rs1042714) in the ADRB2 gene were not associated with blood pressure, hypertension or CVD either in the population overall or in women and men separately.
ADRB2 Thr164Ile is associated with increased blood pressure, increased frequency of hypertension and increased risk of IHD amongst women in the general population. These findings, particularly for homozygotes, are novel.
The ß(2)-adrenergic receptor (ADRB2) influences regulation of energy balance by stimulating catecholamine-induced lipolysis in adipose tissue. The rare functional ADRB2rs1800888(Thr164Ile) polymorphism could therefore influence risk of obesity and subsequently diabetes.
We tested the hypothesis that the ADRB2rs1800888(Thr164Ile) polymorphism associates with risk of obesity and diabetes and compared effect sizes with those of FTO(rs9939609), MC4R(rs17782313), and TMEM18(rs6548238).
We conducted a population-based cohort study in Copenhagen, Denmark.
We genotyped more than 64,000 individuals from the Danish general population.
We evaluated body mass index (BMI), obesity (BMI =30 kg/m(2)), and diabetes.
Rare allele frequencies were 0.02 for T for ADRB2rs1800888(Thr164Ile), 0.40 for A for FTOrs9939609, 0.25 for C for MC4Rrs17782313, and 0.20 for T for TMEM18rs6548238. For rare vs. common homozygotes, odds ratio for obesity was 3.32 (95% confidence interval = 1.08-10.19) for ADRB2rs1800888(Thr164Ile), 1.42 (1.35-1.52) for FTOrs9939609, 1.18 (1.06-1.30) for MC4Rrs17782313, and 1.28 (1.10-1.50) for TMEM18rs6548238 (common vs. rare). Corresponding odds ratios for diabetes were 1.85 (0.24-14.29), 1.22 (1.07-1.39), 0.96 (0.80-1.16), and 1.61 (1.17-2.22), respectively. After adjustment for BMI, only TMEM18rs6548238 remained associated with diabetes. BMI was increased in rare vs. common homozygotes in FTOrs9939609, MC4Rrs17782313, and TMEM18rs6548238 (common vs. rare) but not in ADRB2rs1800888(Thr164Ile).
Our results suggest that ADRB2rs1800888(Thr164Ile) rare vs. common homozygotes are not significantly associated with an increase in BMI measured continuously but may be associated with an increased risk of obesity. Also, TMEM18rs6548238 associated with risk of diabetes after adjustment for BMI. These findings need confirmation in other studies.
The serotonin 2C (HTR2C) receptor has been implicated in suicide-related behaviours, however there are not many studies to date about HTR2C and suicidality. We studied HTR2C haplotypes in suicide attempters, where our sample composed of 306 families with at least one member affected by bipolar disorder. HTR2C (Cys23Ser and a common STR in the promoter) variants were analyzed with respect to attempter status and the severity of suicidal behaviour. The X-linked haplotype analysis in relation to suicide attempt did not reveal any significant association. Furthermore, we performed a particular gene-gene interaction for the X-linked serotonergic genes (HTR2C and MAOA), and found no association among this intergenic haplotype combination and suicidal behaviour in bipolar disorder.
Numerous linkage studies have indicated chromosome 18q21-22 as a locus of importance for blood pressure regulation. This locus harbors the neural precursor cell expressed developmentally downregulated 4-like (NEDD4L) gene, which is instrumental for the regulation of the amiloride-sensitive epithelial sodium channel (ENaC). In a linkage study of 16 markers (including two single nucleotide polymorphism markers located within the NEDD4L gene) on chromosome 18 between 70-104 cM and ambulatory blood pressure (ABP), in 118 families, the strongest evidence of linkage was found for 24 h and day-time systolic ABP at the NEDD4L locus (82.25 cM) (P=0.0014). In a large population sample (n=4001), we subsequently showed that a NEDD4L gene variant (rs4149601), which by alternative splicing leads to varying expression of a functionally crucial C2 domain, was associated with diastolic blood pressure (DBP) (P=0.03) and DBP progression over time (P=0.04). A genotype combination of the rs4149601 and an intronic NEDD4L marker (rs2288774) was associated with systolic blood pressure (SBP) (P=0.01), DBP (P=0.04), and progression of both SBP (P=0.03) and DBP (P=0.05) over time. A quantitative transmission disequilibrium test in the family material of the rs4149601 supported this NEDD4L variant as being at least partially causative of the linkage result. In conclusion, our findings suggest that the chromosome 18 linkage peak at 82.25 cM is explained by genetic NEDD4L variation affecting cross-sectional and longitudinal blood pressure, possibly as a consequence of altered NEDD4L interaction with ENaC.
The -112G>A polymorphism of the secretoglobin 3A2 (SCGB3A2) gene encoding uteroglobin-related protein 1 (UGRP1) increases risk for the development of Graves' disease in subsets of patients with elevated levels of immunoglobulin E.
The human secretoglobin 3A2 (SCGB3A2) gene encoding secretory uteroglobin-related protein 1 (UGRP1) resides on the chromosome region 5q31-33 that harbors a susceptibility locus to several autoimmune and inflammatory diseases, including asthma and Graves' disease (GD). Recently, association between the marker rs1368408 (-112G?>A), located in the promoter region of the SCGB3A2 gene, and susceptibility to GD was found in Chinese and UK Caucasians. The study aim was to evaluate whether this polymorphism confers GD susceptibility in a large population cohort comprising 1,474 Russian GD patients and 1,619 controls. The marker rs1368408 was studied using a TaqMan allele discrimination assay. Serum levels of UGRP1 and immunoglobulin E (IgE) were assessed using enzyme-linked immunosorbent assay (ELISA) analyses. Association between the allele A of SCGB3A2 and a higher risk of GD (odds ratio [OR] = 1.33, P = 2.9 × 10(-5)) was shown. Both affected and non-affected carriers of the higher risk genotype A/A had significantly decreased levels of serum UGRP1 compared to the subjects homozygous for G/G (93 ± 37 pg/ml vs. 132 ± 45 pg/ml, P = 0.0011 for GD patients; 77 ± 28 pg/ml vs. 119 ± 33 pg/ml, P = 0.0019 for controls). Serum IgE levels were significantly higher in non-affected subjects homozygous for A/A compared to control individuals homozygous for G/G (153 ± 46 IU/ml vs. 122 ± 40 IU/ml, P = 0.0095). Our data suggest that the carriage of the SCGB3A2 -112A/A variant increases the risk for GD in subsets of patients with elevated levels of IgE, a hallmark of allergic asthma. Therefore, the SCGB3A2 -112G?>A polymorphism may be considered as a likely marker linking susceptibility to allergy/asthma and GD on chromosome 5q31-33.
The E-cadherin (CDH1) gene has been associated with prostate carcinogenesis. The C/A polymorphism--160 base pairs relative to the transcription start site has been shown to decrease gene transcription. We analyzed the association between this polymorphism and the risk of sporadic, familial (2 close relatives) and hereditary (3 or more close relatives) prostate cancer. We combined data from 3 population-based epidemiologic studies in Sweden encompassing altogether 1,036 prostate cancer cases and 669 controls that were genotyped for the short nucleotide polymorphism. Odds ratios with 95% confidence intervals were estimated through unconditional logistic regression. We found no significant association between the A-allele and sporadic (OR = 1.0; 95% CI = 0.8-1.2) or familial (OR = 1.4; 95% CI = 0.9-2.2) prostate cancer. In contrast, risk of hereditary cancer was increased among heterozygote CA carriers (OR = 1.7; 95% CI = 1.0-2.7) and particularly among homozygote AA carriers (OR = 2.6; 95% CI = 1.4-4.9). Our data indicate that the -160 single nucleotide polymorphism in CDH1 is a low-penetrant prostate cancer susceptibility gene that might explain a proportion of familial and notably hereditary prostate cancer.
The -250G>A promoter variant in hepatic lipase associates with elevated fasting serum high-density lipoprotein cholesterol modulated by interaction with physical activity in a study of 16,156 Danish subjects.
CONTEXT: Hepatic lipase plays a pivotal role in the metabolism of high-density lipoprotein (HDL) and low-density lipoprotein by involvement in reverse cholesterol transport and the formation of atherogenic small dense low-density lipoprotein. OBJECTIVES: The objective was to investigate the impact of variants in LIPC on metabolic traits and type 2 diabetes in a large sample of Danes. Because behavioral factors influence hepatic lipase activity, we furthermore examined possible gene-environment interactions in the population-based Inter99 study. DESIGN: The LIPC -250G>A (rs2070895) variant was genotyped in the Inter99 study (n = 6070), the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen Detected Diabetes in Primary Care Denmark screening cohort of individuals with risk factors for undiagnosed type 2 diabetes (n = 8662), and in additional type 2 diabetic patients (n = 1,064) and glucose-tolerant control subjects (n = 360). RESULTS: In the Inter99 study, the A allele of rs2070895 associated with a 0.057 mmol/liter [95% confidence interval (CI) 0.039-0.075] increase in fasting serum HDL-cholesterol (HDL-c) (P = 8 x 10(-10)) supported by association in the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen Detected Diabetes in Primary Care study [0.038 mmol/liter per allele (95% CI 0.024-0.053); P = 2 x 10(-7)). The allelic effect on HDL-c was modulated by interaction with self-reported physical activity (P(interaction) = 0.002) because vigorous physically active homozygous A-allele carriers had a 0.30 mmol/liter (95% CI 0.22-0.37) increase in HDL-c compared with homozygous G-allele carriers. CONCLUSIONS: We validate the association of LIPC promoter variation with fasting serum HDL-c and present data supporting an interaction with physical activity implying an increased effect on HDL-c in vigorous physically active subjects carrying the -250 A allele. This interaction may have potential implications for public health and disease prevention.
Uncertainty exists whether the 4154delA mutation of the BRCA1 gene detected in unrelated individuals from Latvia, Poland and Russia is a founder mutation with a common ancestral origin. To trace back this problem we analysed the mutation-associated haplotype of the BRCA1 intragenic SNPs as well as intragenic and nearby STR markers in mutation carriers from the aforementioned populations. The mutation-associated SNP alleles were found to be "T-A-A-A-A-G" for six intragenic SNPs of the BRCA1 gene (IVS8-58delT, 3232A/G, 3667A/G, IVS16-68A/G, IVS16-92A/G, IVS18+66G/A, respectively). The alleles 195, 154, 210 and 181 were found to be associated with the 4154delA mutation for STR markers D17S1325, D17S855, D17S1328 and D17S1320, correspondingly. Further analysis of markers in the 4154delA mutation carriers from all three populations allows us to assert that all analysed mutation carriers share a common ancestry.
Polymorphisms in the gene coding for low-density lipoprotein receptor-related protein 5 (LRP5) contribute to variation in bone mass in the general population. Whether this is due to influence on bone mass acquisition or on bone loss thereafter has not been established.
We studied the association of LRP5 polymorphisms with peak bone mass in young men. The study included 235 Finnish men, aged 18.3 to 20.6 years. Lifestyle factors and fracture history were recorded. Bone mineral content (BMC), density (BMD) and scan area were measured for the lumbar spine and proximal femur by dual energy X-ray absorptiometry (DXA). Blood and urine were collected for determination of bone turnover markers, serum 25-OHD and PTH. Genomic DNA was extracted from peripheral blood for genetic analysis of LRP5. Ten single nucleotide polymorphisms in LRP5 were analyzed and correlated with bone parameters.
Only the A1330V polymorphism of LRP5 significantly associated with bone parameters. In comparison with subjects with the AlaAla genotype (n=215), those with AlaVal genotype (n=20) had lower femoral neck BMC (P=0.029) and BMD (P=0.012), trochanter BMC (P=0.0067) and BMD (P=0.015), and total hip BMC (P=0.0044) and BMD (P=0.0089). Fracture history was similar for the genotypes.
The polymorphic valine variant at position 1330 of LRP5 was significantly associated with reduced BMC and BMD values in healthy young Finnish men. The results provide evidence for the crucial role of LRP5 in peak bone mass acquisition.
BACKGROUND AND OBJECTIVE: Many environmental and genetic factors influence the development of chemoresistance. The goal of this study was to characterize the genetic variation in the ABCB1, GSTM1, GSTT1 and GSTP1 genes, as well as the haplotype structure in the ABCB1 gene. METHODS: Variants in these genes were studied in 109 healthy controls and 93 breast cancer cases, both of Caucasian origin. The cases were analyzed in relation to TP53 mutation status and response to doxorubicin. Both single and multiple single nucleotide polymorphism analyses were performed. RESULTS: Chi-square analyses revealed a significant association between TP53 mutation status and both the GA genotype of ABCB1 exon 11 (Ser400Asn) and the GG genotype of GSTP1 (Ile105Val; P