Lisa D.S. Bloomer

Inheritance of coronary artery disease in men: an analysis of the role of the Y chromosome

Summary Background A sexual dimorphism exists in the incidence and prevalence of coronary artery disease—men are more commonly affected than are age-matched women. We explored the role of the Y chromosome in coronary artery disease in the context of this sexual inequity. Methods We genotyped 11 markers of the male-specific region of the Y chromosome in 3233 biologically unrelated British men from three cohorts: the British Heart Foundation Family Heart Study (BHF-FHS), West of Scotland Coronary Prevention Study (WOSCOPS), and Cardiogenics Study. On the basis of this information, each Y chromosome was tracked back into one of 13 ancient lineages defined as haplogroups. We then examined associations between common Y chromosome haplogroups and the risk of coronary artery disease in cross-sectional BHF-FHS and prospective WOSCOPS. Finally, we undertook functional analysis of Y chromosome effects on monocyte and macrophage transcriptome in British men from the Cardiogenics Study. Findings Of nine haplogroups identified, two (R1b1b2 and I) accounted for roughly 90% of the Y chromosome variants among British men. Carriers of haplogroup I had about a 50% higher age-adjusted risk of coronary artery disease than did men with other Y chromosome lineages in BHF-FHS (odds ratio 1·75, 95% CI 1·20–2·54, p=0·004), WOSCOPS (1·45, 1·08–1·95, p=0·012), and joint analysis of both populations (1·56, 1·24–1·97, p=0·0002). The association between haplogroup I and increased risk of coronary artery disease was independent of traditional cardiovascular and socioeconomic risk factors. Analysis of macrophage transcriptome in the Cardiogenics Study revealed that 19 molecular pathways showing strong differential expression between men with haplogroup I and other lineages of the Y chromosome were interconnected by common genes related to inflammation and immunity, and that some of them have a strong relevance to atherosclerosis. Interpretation The human Y chromosome is associated with risk of coronary artery disease in men of European ancestry, possibly through interactions of immunity and inflammation. Funding British Heart Foundation; UK National Institute for Health Research; LEW Carty Charitable Fund; National Health and Medical Research Council of Australia; European Union 6th Framework Programme; Wellcome Trust.

Male-Specific Region of the Y Chromosome and Cardiovascular Risk Phylogenetic Analysis and Gene Expression Studies

Objective—Haplogroup I of male-specific region of the human Y chromosome is associated with 50% increased risk of coronary artery disease. It is not clear to what extent conventional cardiovascular risk factors and genes of the male-specific region may explain this association. Approach and Results—A total of 1988 biologically unrelated men from 4 white European populations were genotyped using 11 Y chromosome single nucleotide polymorphisms and classified into 13 most common European haplogroups. Approximately 75% to 93% of the haplotypic variation of the Y chromosome in all cohorts was attributable to I, R1a, and R1b1b2 lineages. None of traditional cardiovascular risk factors, including body mass index, blood pressures, lipids, glucose, C-reactive protein, creatinine, and insulin resistance, was associated with haplogroup I of the Y chromosome in the joint inverse variance meta-analysis. Fourteen of 15 ubiquitous single-copy genes of the male-specific region were expressed in human macrophages. When compared with men with other haplogroups, carriers of haplogroup I had ≈0.61- and 0.64-fold lower expression of ubiquitously transcribed tetratricopeptide repeat, Y-linked gene (UTY) and protein kinase, Y-linked, pseudogene (PRKY) in macrophages (P=0.0001 and P=0.002, respectively). Conclusions—Coronary artery disease predisposing haplogroup I of the Y chromosome is associated with downregulation of UTY and PRKY genes in macrophages but not with conventional cardiovascular risk factors.Objective— Haplogroup I of male-specific region of the human Y chromosome is associated with 50% increased risk of coronary artery disease. It is not clear to what extent conventional cardiovascular risk factors and genes of the male-specific region may explain this association. Approach and Results— A total of 1988 biologically unrelated men from 4 white European populations were genotyped using 11 Y chromosome single nucleotide polymorphisms and classified into 13 most common European haplogroups. Approximately 75% to 93% of the haplotypic variation of the Y chromosome in all cohorts was attributable to I, R1a, and R1b1b2 lineages. None of traditional cardiovascular risk factors, including body mass index, blood pressures, lipids, glucose, C-reactive protein, creatinine, and insulin resistance, was associated with haplogroup I of the Y chromosome in the joint inverse variance meta-analysis. Fourteen of 15 ubiquitous single-copy genes of the male-specific region were expressed in human macrophages. When compared with men with other haplogroups, carriers of haplogroup I had ≈0.61- and 0.64-fold lower expression of ubiquitously transcribed tetratricopeptide repeat, Y-linked gene ( UTY ) and protein kinase, Y-linked, pseudogene ( PRKY ) in macrophages ( P =0.0001 and P =0.002, respectively). Conclusions— Coronary artery disease predisposing haplogroup I of the Y chromosome is associated with downregulation of UTY and PRKY genes in macrophages but not with conventional cardiovascular risk factors. # Significance {#article-title-29}

The Epithelial Sodium Channel γ-Subunit Gene and Blood Pressure: Family Based Association, Renal Gene Expression, and Physiological Analyses

Variants in the gene encoding the &ggr;-subunit of the epithelial sodium channel (SCNN1G) are associated with both Mendelian and quantitative effects on blood pressure. Here, in 4 cohorts of 1611 white European families composed of a total of 8199 individuals, we undertook staged testing of candidate single-nucleotide polymorphisms for SCNN1G (supplemented with imputation based on data from the 1000 Genomes Project) followed by a meta-analysis in all of the families of the strongest candidate. We also examined relationships between the genotypes and relevant intermediate renal phenotypes, as well as expression of SCNN1G in human kidneys. We found that an intronic single-nucleotide polymorphism of SCNN1G (rs13331086) was significantly associated with age-, sex-, and body mass index–adjusted blood pressure in each of the 4 populations (P<0.05). In an inverse variance-weighted meta-analysis of this single-nucleotide polymorphism in all 4 of the populations, each additional minor allele copy was associated with a 1-mm Hg increase in systolic blood pressure and 0.52-mm Hg increase in diastolic blood pressure (SE=0.33, P=0.002 for systolic blood pressure; SE=0.21, P=0.011 for diastolic blood pressure). The same allele was also associated with higher 12-hour overnight urinary potassium excretion (P=0.04), consistent with increased epithelial sodium channel activity. Renal samples from hypertensive subjects showed a nonsignificant (P=0.07) 1.7-fold higher expression of SCNN1G compared with normotensive controls. These data provide genetic and phenotypic evidence in support of a role for a common genetic variant of SCNN1G in blood pressure determination.

Coronary artery disease predisposing haplogroup I of the Y chromosome, aggression and sex steroids – Genetic association analysis

OBJECTIVE Amongst middle-aged men, haplogroup I is associated with ≈ 50% higher risk of coronary artery disease than other paternal lineages of Y chromosome. We hypothesised that carriers of haplogroup I had higher levels of aggression and estrogens and/or lower levels of androgens early in life and thus might be more prone to cardiovascular disease than men with other lineages of Y chromosome. METHODS We reconstructed phylogenetic tree of the Y chromosome in >1000 young apparently healthy white men from the general population. Each Y chromosome was classified into one of 13 most common European lineages. Androgens (DHEA-S, androstenedione, total testosterone) and their metabolites (total estradiol, estrone) were measured by radioimmunoassays. Information on five dimensions of aggression (total, physical, verbal, anger and hostility) was collected using Buss and Perry questionnaire. RESULTS Approximately 17% men inherited haplogroup I from their fathers. Carriers of haplogroup I showed lower scores of verbal aggression than men with other haplogroups (β = -0.72, SE = 0.29, P = 0.012) and when further compared to carriers of most common R1a lineage and other haplogroups (β = -1.03, SE = 0.34, P = 0.003). However, these associations did not survive a correction for multiple testing. Sex steroids did not show even nominal level of association with haplogroup I. CONCLUSION Our data show no overall association between haplogroup I and sex-related phenotypes in young white men. These results also suggest that the previously identified association between haplogroup I and coronary artery disease is not likely mediated by unfavourable profile of sex steroids or heightened aggression early in life.

Urotensin-II System in Genetic Control of Blood Pressure and Renal Function

Urotensin-II controls ion/water homeostasis in fish and vascular tone in rodents. We hypothesised that common genetic variants in urotensin-II pathway genes are associated with human blood pressure or renal function. We performed family-based analysis of association between blood pressure, glomerular filtration and genes of the urotensin-II pathway (urotensin-II, urotensin-II related peptide, urotensin-II receptor) saturated with 28 tagging single nucleotide polymorphisms in 2024 individuals from 520 families; followed by an independent replication in 420 families and 7545 unrelated subjects. The expression studies of the urotensin-II pathway were carried out in 97 human kidneys. Phylogenetic evolutionary analysis was conducted in 17 vertebrate species. One single nucleotide polymorphism (rs531485 in urotensin-II gene) was associated with adjusted estimated glomerular filtration rate in the discovery cohort (p = 0.0005). It showed no association with estimated glomerular filtration rate in the combined replication resource of 8724 subjects from 6 populations. Expression of urotensin-II and its receptor showed strong linear correlation (r = 0.86, p<0.0001). There was no difference in renal expression of urotensin-II system between hypertensive and normotensive subjects. Evolutionary analysis revealed accumulation of mutations in urotensin-II since the divergence of primates and weaker conservation of urotensin-II receptor in primates than in lower vertebrates. Our data suggest that urotensin-II system genes are unlikely to play a major role in genetic control of human blood pressure or renal function. The signatures of evolutionary forces acting on urotensin-II system indicate that it may have evolved towards loss of function since the divergence of primates.

Male-Specific Region of the Y Chromosome and Cardiovascular Risk

Objective—Haplogroup I of male-specific region of the human Y chromosome is associated with 50% increased risk of coronary artery disease. It is not clear to what extent conventional cardiovascular risk factors and genes of the male-specific region may explain this association. Approach and Results—A total of 1988 biologically unrelated men from 4 white European populations were genotyped using 11 Y chromosome single nucleotide polymorphisms and classified into 13 most common European haplogroups. Approximately 75% to 93% of the haplotypic variation of the Y chromosome in all cohorts was attributable to I, R1a, and R1b1b2 lineages. None of traditional cardiovascular risk factors, including body mass index, blood pressures, lipids, glucose, C-reactive protein, creatinine, and insulin resistance, was associated with haplogroup I of the Y chromosome in the joint inverse variance meta-analysis. Fourteen of 15 ubiquitous single-copy genes of the male-specific region were expressed in human macrophages. When compared with men with other haplogroups, carriers of haplogroup I had ≈0.61- and 0.64-fold lower expression of ubiquitously transcribed tetratricopeptide repeat, Y-linked gene (UTY) and protein kinase, Y-linked, pseudogene (PRKY) in macrophages (P=0.0001 and P=0.002, respectively). Conclusions—Coronary artery disease predisposing haplogroup I of the Y chromosome is associated with downregulation of UTY and PRKY genes in macrophages but not with conventional cardiovascular risk factors.Objective— Haplogroup I of male-specific region of the human Y chromosome is associated with 50% increased risk of coronary artery disease. It is not clear to what extent conventional cardiovascular risk factors and genes of the male-specific region may explain this association. Approach and Results— A total of 1988 biologically unrelated men from 4 white European populations were genotyped using 11 Y chromosome single nucleotide polymorphisms and classified into 13 most common European haplogroups. Approximately 75% to 93% of the haplotypic variation of the Y chromosome in all cohorts was attributable to I, R1a, and R1b1b2 lineages. None of traditional cardiovascular risk factors, including body mass index, blood pressures, lipids, glucose, C-reactive protein, creatinine, and insulin resistance, was associated with haplogroup I of the Y chromosome in the joint inverse variance meta-analysis. Fourteen of 15 ubiquitous single-copy genes of the male-specific region were expressed in human macrophages. When compared with men with other haplogroups, carriers of haplogroup I had ≈0.61- and 0.64-fold lower expression of ubiquitously transcribed tetratricopeptide repeat, Y-linked gene ( UTY ) and protein kinase, Y-linked, pseudogene ( PRKY ) in macrophages ( P =0.0001 and P =0.002, respectively). Conclusions— Coronary artery disease predisposing haplogroup I of the Y chromosome is associated with downregulation of UTY and PRKY genes in macrophages but not with conventional cardiovascular risk factors. # Significance {#article-title-29}

Male-Specific Region of the Y Chromosome and Cardiovascular RiskSignificance

Objective—Haplogroup I of male-specific region of the human Y chromosome is associated with 50% increased risk of coronary artery disease. It is not clear to what extent conventional cardiovascular risk factors and genes of the male-specific region may explain this association. Approach and Results—A total of 1988 biologically unrelated men from 4 white European populations were genotyped using 11 Y chromosome single nucleotide polymorphisms and classified into 13 most common European haplogroups. Approximately 75% to 93% of the haplotypic variation of the Y chromosome in all cohorts was attributable to I, R1a, and R1b1b2 lineages. None of traditional cardiovascular risk factors, including body mass index, blood pressures, lipids, glucose, C-reactive protein, creatinine, and insulin resistance, was associated with haplogroup I of the Y chromosome in the joint inverse variance meta-analysis. Fourteen of 15 ubiquitous single-copy genes of the male-specific region were expressed in human macrophages. When compared with men with other haplogroups, carriers of haplogroup I had ≈0.61- and 0.64-fold lower expression of ubiquitously transcribed tetratricopeptide repeat, Y-linked gene (UTY) and protein kinase, Y-linked, pseudogene (PRKY) in macrophages (P=0.0001 and P=0.002, respectively). Conclusions—Coronary artery disease predisposing haplogroup I of the Y chromosome is associated with downregulation of UTY and PRKY genes in macrophages but not with conventional cardiovascular risk factors.Objective— Haplogroup I of male-specific region of the human Y chromosome is associated with 50% increased risk of coronary artery disease. It is not clear to what extent conventional cardiovascular risk factors and genes of the male-specific region may explain this association. Approach and Results— A total of 1988 biologically unrelated men from 4 white European populations were genotyped using 11 Y chromosome single nucleotide polymorphisms and classified into 13 most common European haplogroups. Approximately 75% to 93% of the haplotypic variation of the Y chromosome in all cohorts was attributable to I, R1a, and R1b1b2 lineages. None of traditional cardiovascular risk factors, including body mass index, blood pressures, lipids, glucose, C-reactive protein, creatinine, and insulin resistance, was associated with haplogroup I of the Y chromosome in the joint inverse variance meta-analysis. Fourteen of 15 ubiquitous single-copy genes of the male-specific region were expressed in human macrophages. When compared with men with other haplogroups, carriers of haplogroup I had ≈0.61- and 0.64-fold lower expression of ubiquitously transcribed tetratricopeptide repeat, Y-linked gene ( UTY ) and protein kinase, Y-linked, pseudogene ( PRKY ) in macrophages ( P =0.0001 and P =0.002, respectively). Conclusions— Coronary artery disease predisposing haplogroup I of the Y chromosome is associated with downregulation of UTY and PRKY genes in macrophages but not with conventional cardiovascular risk factors. # Significance {#article-title-29}

423 ANDROGENS AND AGGRESSIVENESS DO NOT MEDIATE THE EFFECT OF THE Y CHROMOSOME ON CARDIOVASCULAR RISK

Introduction: Men develop coronary artery disease (CAD) ∼10 years earlier than age-matched women at a ratio of 2:1. A major biological difference between the genders, possibly accounting for this “male disadvantage”, is the Y chromosome. Haplogroup I of the Y chromosome increases risk of CAD by ∼50%. We sought to investigate if “male-specific” phenotypes previously associated with CAD may explain this effect. Methodology: We examined whether various measures of aggression and/or androgens may account for the association between haplogroup I and cardiovascular risk. 11 Y chromosome polymorphisms were genotyped in 1940 men (GRAPHIC, YMCA1, YMCA2) and using phylogenetic analysis each subject was assigned one Y chromosome lineage. Age-adjusted linear regression and fixed-effect inverse-variance meta-analysis was used to examine the effect of haplogroup I on each phenotype. Results: Meta-analysis of 1940 men showed no statistical difference in BMI, blood-pressure, lipids, glucose or renal function between carriers of haplogroup I and all other haplogroups. There were no statistical differences in measures of aggression in age-adjusted meta-analysis of 998 men from YMCA1 and 2 (meta-analysis p = 0.092, p = 0.016, p = 0.155, p = 0.315 and p = 0.164 for physical aggression, verbal aggression, anger, hostility and total aggression, respectively) after correction for multiple testing. Haplogroup I was also not associated with circulating levels of androgens in 861 men from YMCA1 (p = 0.388, p = 0912, p = 0.665, for testosterone, androstendione and DHEA-S respectively). Conclusions: These results suggest that neither traditional cardiovascular risk factors nor traits typically perceived as “male-specific” are likely to account for the association between the Y chromosome and cardiovascular risk.

PHYLOGENETIC ANALYSIS OF THE Y CHROMOSOME IN ABDOMINAL AORTIC ANEURYSMS: A META-ANALYSIS OF THREE BRITISH COHORTS.

Introduction: Coronary artery disease (CAD) and abdominal aortic aneurysms (AAA) are significantly sexually dimorphic; men develop and die of CAD and AAA more commonly than age-matched women. Haplogroup I of the Y chromosome as a strong, independent risk factor of CAD. As both diseases are sexually dimorphic clinical manifestations of cardiovascular disease we hypothesised that haplogroup I of the Y chromosome may underlie the genetic background that drives the male predominance at diagnosis. Methodology: A total of 2917 (mean age 70years, mean aneurysm diameter 6 cm) men recruited into three British cohorts were genotyped for 11 Y chromosome polymorphisms. Using this information and Y chromosome phylogenetic analysis, each man was assigned one common European Y chromosome lineage. Using age-adjusted linear regression and fixed-effect inverse variance meta-analysis we examined the effect of haplogroup I on the risk of AAA. Results: The distribution of haplogroups identified in each of the three cohorts was in keeping with published prevalence (prevalence of haplogroup I ranged from 14% to 20%). There was no statistically significant individual associations between haplogroup I and age-adjusted risk of AAA in either of three cohorts (p=0.643, p=0.815 and p=0.530 in Leicester, Leeds, and Belfast, respectively). The fixed effect meta-analysis of the three cohorts confirmed that haplogroup I had no affect on the age-adjusted risk of AAA (p= 0.693). Conclusions: Haplogroup I of the Y chromosome does not predispose its carriers to AAA. This may suggest that significant differences in the genetic architecture of sexual dimorphism between AAA and CAD.

69 A FUNCTIONAL GENETIC VARIANT OF FGF1 IS ASSOCIATED WITH BLOOD PRESSURE IN THE GENERAL POPULATION

Background: Fibroblast growth factor-1 gene (FGF1) and its partner molecules were previously associated with human hypertension. We examined whether the lead common polymorphism of FGF1 (rs152524) is associated with blood pressure (BP) in the general population of white European ethnicity and whether this association may have functional consequences at the gene expression level. Methods and results: The inverse variance meta-analysis of 14972 subjects from 6 cohorts (Silesian Hypertension Study, Silesian Cardiovascular Study, Young Men Cardiovascular Association Study, Genetic Regulation of Arterial Pressure of Humans in the Community, Victorian Family Heart Study, Prevention of Renal and Vascular End-stage Disease PREVEND Study) revealed that each major allele of rs152524 was associated with 0.9-mmHg and 0.3-mmHg increase in adjusted clinic SBP (P = 8.39x10−5) and DBP (P = 8.16x10−3). The major allele of rs152524 was also associated with a significant increase in adjusted mean 24-hour DBP in 1987 subjects with available 24-hour ambulatory BP monitoring (p = 0.0470). Our comparative expression analysis of 6-week old spontaneously hypertensive (SHR, n = 5) and Wistar-Kyoto (WKY, n = 5) rats revealed that FGF1 was up-regulated in the kidney (p = 0.035) but not in the aorta of SHR (p = 0.7758). We identified 2 alternative transcripts of FGF1 (FGF1-001 and FGF1-002) in the human kidney. Using 121 human samples from Polish Kidney Tissue Bank we uncovered that the major allele of rs152524 was associated with up-regulation of one of these transcripts (FGF1-001) in the kidney (p = 0.005). Conclusions: Common allelic variant of FGF1 up-regulates one of its transcripts in the kidney and associates with BP elevation in the general population.