Search

Background: Rs1333040 is the single-nucleotide polymorphisms (SNP) related with coronary heart disease (CHD). The aim of the present study is to examine the association between rs1333040 polymorphism genotypes and CHD and to further explore the molecular mechanism in Chinese population. Methods: A case-control study was used in this study, including 500 CHD patients and 500 control subjects. CHD patients and controls were distinguished by coronary angiography. Genotypes of rs1333040 were determined on the Agena MassARRAY system. Statistical analysis was conducted by SPSS (Ver 16.0) and plink (Ver. 1.07, Shaun Purcell). Results: Fisher's exact test by plink indicated a significant difference in the allele distribution between cases and controls, the allele T may be associated with a higher risk of CHD (p = 0.012, odds ratio (OR) = 1.258). The serum levels of low-density lipoprotein cholesterol (LDL-C) (p = 0.029) and Gensini score (p = 0.008) distributed differently in patients with various alleles. In the recessive model, the levels of high-density lipoprotein (HDL) and apolipoprotein A (ApoA) were higher in the TC + CC genotype than in the TT genotype. The TC + TT genotype was found to be risk factors against CHD in a dominant model (OR = 1.278, p = 0.014). The TC + TT genotype along with multiple risk factors significantly positively correlated with the risk of CHD. Conclusions: The present study investigates the association between the rs1333040 polymorphism genotypes and CHD. The T allele of rs1333040 is the susceptibility site of CHD. The interaction between SNP and various risk factors plays an important role in the development of CHD. [ABSTRACT FROM AUTHOR]

CDKN2A/B deletion or silencing is common across human cancer, reinforcing the general importance of bypassing its tumor suppression in cancer formation or progression. In rhabdomyosarcoma (RMS) and neuroblastoma, two common childhood cancers, the three CDKN2A/B transcripts are independently expressed to varying degrees, but one, ARF, is uniformly silenced. Although TGFβ induces certain CDKN2A/B transcripts in HeLa cells, it was unable to do so in five tested RMS lines unless the cells were pretreated with a broadly acting methyltransferase inhibitor, DZNep, or one targeting EZH2. CDKN2A/B induction by TGFβ correlated with de novo appearance of three H3K27Ac peaks within a 20 kb cis element ∼150 kb proximal to CDKN2A/B. Deleting that segment prevented their induction by TGFβ but not a basal increase driven by methyltransferase inhibition alone. Expression of two CDKN2A/B transcripts was enhanced by dCas9/CRISPR activation targeting either the relevant promoter or the 20 kb cis elements, and this "precise" manipulation diminished RMS cell propagation in vitro. Our findings show crosstalk between methyltransferase inhibition and TGFβ-dependent activation of a remote enhancer to reverse CDKN2A/B silencing. Though focused on CDKN2A/B here, such crosstalk may apply to other TGFβ-responsive genes and perhaps govern this signaling protein's complex effects promoting or blocking cancer. [ABSTRACT FROM AUTHOR]

Several studies have reported that chromosome 9p21 is significantly associated with ischemic stroke (IS) risk, with the G allele associated with increased risk. However, controversial results have been reported in the literature. We systematically assessed the relationship between stroke and three 9p21 loci (rs2303206, rs2383207, and rs10757278) in this meta-analysis. First, we searched the PubMed and Embase databases for relevant studies. We then calculated odds ratios using the chi-squared test. The evaluation of experimental data was performed using bias tests and sensitivity analyses. We analyzed data from 16 studies involving 18,584 individuals of Chinese ancestry, including 14,033 cases and 14,656 controls. Our results indicated that chromosome 9p21 is significantly associated with IS (odds ratio: 1.15, 95% confidence interval: 1.1–1.20, p < 0.0001). Because the three single-nucleotide polymorphisms (rs2383206, rs2383207, and 10757278) have a linkage disequilibrium relationship, all three may increase the risk of IS. [ABSTRACT FROM AUTHOR]

Several studies have reported that chromosome 9p21 is significantly associated with ischemic stroke (IS) risk, with the G allele associated with increased risk. However, controversial results have been reported in the literature. We systematically assessed the relationship between stroke and three 9p21 loci (rs2383206, rs2383207, and rs10757278) in this meta-analysis. First, we searched the PubMed and Embase databases for relevant studies. We then calculated odds ratios using the chi-squared test. The evaluation of experimental data was performed using bias tests and sensitivity analyses. We analyzed data from 16 studies involving 18,584 individuals of Chinese ancestry, including 14,033 cases and 14,656 controls. Our results indicated that chromosome 9p21 is significantly associated with IS (odds ratio: 1.15, 95% confidence interval: 1.1–1.20, p < 0.0001). Because the three single-nucleotide polymorphisms (rs2383206, rs2383207, and 10757278) have a linkage disequilibrium relationship, all three may increase the risk of IS.

Abstract Background Rs4977574 (A > G) and Rs1333045 (C > T) are both single nucleotide polymorphisms (SNPs) related with coronary artery disease, locating on chromosome 9p21.3. The study aimed to identify the correlation between rs4977574 and rs1333045 polymorphism genotypes and coronary heart disease (CHD) in a Chinese population. Methods Blood samples were collected from 855 subjects. A case-control study was used in this experiment, and 598 cases in the CHD group and 257 subjects in the control group were enrolled. Genotyping was identified by the Agena MassARRAY system. Statistical analysis was conducted by SPSS (Ver 16.0) and plink (Ver. 1.07, Shaun Purcell). Haplotype analysis was performed using Haploview software. Results Association analysis by plink indicated a significant difference in the allele distribution for single nucleotide polymorphisms between cases and controls (rs4977574 P = 0.003, rs1333045 P = 0.035). Fisher’s exact test by plink proved that allele G may be associated with a higher risk of CHD (P = 0.003, odds ratio (OR) = 1.371) and the T allele was likely to reduce the risk of coronary events (P = 0.035, OR = 0.798). The serum levels of apolipoprotein A (ApoA) were higher in subjects with the AG + AA genotype of rs4977574 compared to those with the GG genotype (P = 0.028). In the dominant model of rs1333045, the levels of ApoA were higher and LDL levels were lower in the TC + TT genotype than in the CC genotype. Conclusions The present study examined the association between the 9p21 chromosome rs4977574 and rs1333045 polymorphism genotypes and CHD in a population of Chinese patients. The G allele of rs4977574 and the C allele of rs1333045 are the susceptibility sites of CHD.

Background and objectives: Several genetic studies have demonstrated an association between genetic variants in a region on chromosome 9p21 and acute myocardial infarction. We aimed to investigate the association between the cyclin-dependent kinase inhibitor 2B antisense RNA rs1333049 single nucleotide polymorphisms on chromosome 9p21 and acute myocardial infarction, in addition to determine the association between risk genotypes and 1- year outcome in such patients. Methods: A total of 150 subjects (100 patients with acute myocardial infarction and 50 participants as a controls) were enrolled in the study. All subjects underwent genotyping of rs1333049. Patients were followed up for 1 year for development of reoccurrence of myocardial infarction, re-coronary intervention and cardiovascular death. Results: The frequency of the GC and CC genotypes of rs1333049 is higher in patients in comparison with controls (54% vs 36% and 36% vs 18% respectively, p<0.001), while controls demonstrated increased frequency of GG genotypes (46% vs 10%, p<0.001). In a multivariate logistic regression analysis. GC and CC genotypes were independent risk factors for myocardial infarction (Odd`s ratio was 174.67, p=0.005). New myocardial ischemic event was significantly higher among the carriers of the CC and CG genotypes compared with patients with homozygous GG genotype (43.3% vs 10%, p value= 0.041). Conclusion: Cyclin-dependent kinase inhibitor 2B antisense RNA rs1333049 single nucleotide polymorphisms is associated with acute myocardial infarction. The carriers of the CC and CG genotypes are at risk for new coronary events rather than homozygous GG genotype in 1 year follow up. [ABSTRACT FROM AUTHOR]

Background: Rs4977574 (A > G) and Rs1333045 (C > T) are both single nucleotide polymorphisms (SNPs) related with coronary artery disease, locating on chromosome 9p21.3. The study aimed to identify the correlation between rs4977574 and rs1333045 polymorphism genotypes and coronary heart disease (CHD) in a Chinese population. Methods: Blood samples were collected from 855 subjects. A case-control study was used in this experiment, and 598 cases in the CHD group and 257 subjects in the control group were enrolled. Genotyping was identified by the Agena MassARRAY system. Statistical analysis was conducted by SPSS (Ver 16.0) and plink (Ver. 1.07, Shaun Purcell). Haplotype analysis was performed using Haploview software. Results: Association analysis by plink indicated a significant difference in the allele distribution for single nucleotide polymorphisms between cases and controls (rs4977574 P = 0.003, rs1333045 P = 0.035). Fisher's exact test by plink proved that allele G may be associated with a higher risk of CHD (P = 0.003, odds ratio (OR) = 1.371) and the T allele was likely to reduce the risk of coronary events (P = 0.035, OR = 0.798). The serum levels of apolipoprotein A (ApoA) were higher in subjects with the AG + AA genotype of rs4977574 compared to those with the GG genotype (P = 0.028). In the dominant model of rs1333045, the levels of ApoA were higher and LDL levels were lower in the TC + TT genotype than in the CC genotype. Conclusions: The present study examined the association between the 9p21 chromosome rs4977574 and rs1333045 polymorphism genotypes and CHD in a population of Chinese patients. The G allele of rs4977574 and the C allele of rs1333045 are the susceptibility sites of CHD. [ABSTRACT FROM AUTHOR]

Background: Based on several reports including genome-wide association studies, genetic variability has been linked with higher (nearly half) susceptibility toward coronary artery disease (CAD). We aimed to evaluate the association of chromosome 9p21 single nucleotide polymorphisms (SNPs): rs2383207, rs10757278, and rs10757274 with the risk and severity of CAD among Arab population. Materials and Methods: A prospective observational case-control study was conducted between 2011 and 2012, in which 236 patients with CAD were recruited from the Heart Hospital in Qatar. Patients were categorized according to their coronary angiographic findings. Also, 152 healthy volunteers were studied to determine if SNPs are associated with risk of CAD. All subjects were genotyped for SNPs (rs2383207, rs2383206, rs10757274 and rs10757278) using allele-specific real-time polymerase chain reaction. Results: Patients with CAD had a mean age of 57 ± 10; of them 77% were males, 54% diabetics, and 25% had family history of CAD. All SNPs were in Hardy-Weinberg equilibrium except rs2383206, with call rate >97%. After adjusting for age, sex and body mass index, the carriers of GG genotype for rs2383207 have increased the risk of having CAD with odds ratio (OR) of 1.52 (95% confidence interval [CI] = 1.01-2.961, P = 0.046). Also, rs2383207 contributed to CAD severity with adjusted OR 1.80 (95% CI = 1.04-3.12, P = 0.035) based on the dominant genetic model. The other SNPs (rs10757274 and rs10757278) showed no significant association with the risk of CAD or its severity. Conclusion: Among Arab population in Qatar, only G allele of rs2483207 SNP is significantly associated with risk of CAD and its severity.

Atherosclerotic cardiovascular disease ( CVD) is a leading cause of mortality and morbidity worldwide, with coronary artery disease ( CAD) being the single leading cause of death. Better control of risk factors, enhanced diagnostic techniques and improved medical therapies have all substantially decreased the mortality of CAD in developed countries. However, CAD and other forms of atherosclerotic CVD are projected to remain the leading cause of death by 2030 and we face a number of challenges if the outcomes of CAD are to be further improved. The fact that a substantial fraction of high-risk subjects do not reach treatment goals for important risk factors is one of these challenges. At the same time, there is also a non-negotiable fraction of 'concealed' high-risk subjects who are not detected by current risk algorithms and diagnostic modalities. In recent years, we have started to rapidly increase our knowledge of the framework of common genetics underlying CAD and atherosclerotic CVD in the population. In conjunction with modern diagnostic and therapeutic options, this new genetic knowledge may provide a valuable tool for further improvements in prevention. This review summarizes the recent findings from the search for common genetic risk factors for CAD. Furthermore, the author discusses how such recent findings could potentially be used in a number of clinical applications within CAD prevention, including in clinical risk stratification, in prediction of drug treatment response and in the search for targets for novel preventive therapies. [ABSTRACT FROM AUTHOR]

• Lower mRNA levels of CDKN2A and CDKN2B, as well as higher mRNA level of MTAP may be related to CHD. • Rs2383207 may affect the occurrence of CHD by influencing the patients'CDKN2A mRNA expression level. • ANRIL may not be related to the occurrence of CHD in Chinese Han population. [ABSTRACT FROM AUTHOR]

The single nucleotide polymorphisms (SNPs) related to both coronary heart disease (CHD) and ischemic stroke (IS) in Chinese individuals have not been identified definitely. This study was developed to evaluate the genetic susceptibility to CHD and IS on the chromosome 9p21 and the adenosine triphosphate (ATP)-binding cassette transporter A1 genes (ABCA1) in a Chinese Han population. Genotypes of the rs1333040, rs1333042, rs4977574, rs2066715 and rs2740483 SNPs were determined in 1134 unrelated patients (CHD, 565 and IS, 569) and 541 controls. The frequencies of the rs4977574 genotypes and alleles between CHD and control groups, and the rs2740483 genotypes and alleles between IS and control groups were different (p = 0.006-0.001). The subjects with rs1333042GG genotype and the carriers of the rs4977574G allele were associated with increased risk of CHD. The carriers of the rs4977574G allele were associated with increased risk of IS. However, the carriers of the rs2740483C allele had lower risk of IS than the non-carriers of the rs2740483C allele after controlling for potential confounders. The rs4977574GG-age (>60 year) interaction increased the risk of CHD (p = 0.022), whereas the rs2740483CG/CC-body mass index (>24 kg/m²) interaction decreased the risk of IS (p = 0.035). The interactions of rs1333040-rs1333042 on the risk of CHD and IS were relatively strong, whereas the interactions of rs1333040-rs1333042-rs2066715 and rs1333040-rs1333042-rs2066715-rs2740483 on the risk of CHD, and rs1333040-rs1333042-rs4977574 and rs1333040-rs1333042-rs4977574-rs2740483 on the risk of IS were relatively weak. These findings suggest that some common variants on the chromosome 9p21 and ABCA1 and their interactions may significantly modify the risk of CHD and IS independent of effects on serum lipid levels. [ABSTRACT FROM AUTHOR]

Coronary artery disease (CAD) and its severe clinical complication of myocardial infarction is the primary cause of human mortality in the modern society, however, its pathogenesis is complex. The current studies suggest that CAD is a multi gene genetic disease caused by both of genetic and environmental factors. The researchers found that there are many susceptibility loci associated with CAD by analysis of genome wide association study (GWAS). The chromosome 9p21 polymorphism associated with CAD and myocardial infarction becomes the focus, but the mechanisms of high incidence of CAD caused by current gene are still not clear. This article reviewed on the progress in CAD and related studies about chromosome 9p21 in recent years. [ABSTRACT FROM AUTHOR]

Background: Based on several reports including genome-wide association studies, genetic variability has been linked with higher (nearly half) susceptibility toward coronary artery disease (CAD). We aimed to evaluate the association of chromosome 9p21 single nucleotide polymorphisms (SNPs): rs2383207, rs10757278, and rs10757274 with the risk and severity of CAD among Arab population. Materials and Methods: A prospective observational case-control study was conducted between 2011 and 2012, in which 236 patients with CAD were recruited from the Heart Hospital in Qatar. Patients were categorized according to their coronary angiographic findings. Also, 152 healthy volunteers were studied to determine if SNPs are associated with risk of CAD. All subjects were genotyped for SNPs (rs2383207, rs2383206, rs10757274 and rs10757278) using allele-specific real-time polymerase chain reaction. Results: Patients with CAD had a mean age of 57 ± 10; of them 77% were males, 54% diabetics, and 25% had family history of CAD. All SNPs were in Hardy-Weinberg equilibrium except rs2383206, with call rate >97%. After adjusting for age, sex and body mass index, the carriers of GG genotype for rs2383207 have increased the risk of having CAD with odds ratio (OR) of 1.52 (95% confidence interval [CI] = 1.01-2.961, P = 0.046). Also, rs2383207 contributed to CAD severity with adjusted OR 1.80 (95% CI = 1.04-3.12, P = 0.035) based on the dominant genetic model. The other SNPs (rs10757274 and rs10757278) showed no significant association with the risk of CAD or its severity. Conclusion: Among Arab population in Qatar, only G allele of rs2483207 SNP is significantly associated with risk of CAD and its severity. [ABSTRACT FROM AUTHOR]

Background Several studies have demonstrated that variants on chromosome 9p21 confer susceptibility to ischemic stroke (IS) disease. But, the results of variants' roles in Chinese IS population are blank or inconsistent. Methods We performed a case–control analysis in 116 patients with IS and 118 non-IS controls of Han background to determine whether 4 single nucleotide polymorphisms were associated with IS. DNA was extracted from saliva using a magnetic nanoparticles–based method. Results After we adjusted for clinical parameters, we found that the rs10757278-GG genotype conveyed 1.88-fold (95% confidence interval [CI], 1.1-3.1; P = .015), the rs1537378-C allele conveyed 2.0-fold (95% CI, 1.2-3.5; P = .008), and the rs1333047-TT genotype conveyed 1.64-fold (95% CI, 1.02-2.6; P = .041) increased risk of IS, respectively. In addition, there is a significant difference of the lipids level between GG genotype compared with that of AA genotype in rs10757278 ( P < .05). Conclusions This study is the first one to demonstrate that the rs10757278-GG genotype, the rs1537378-C allele, and rs1333047-TT genotype are associated with IS in Chinese Han populations. More importantly, the variant of rs10757278 may have different degrees of influence on lipids level. [ABSTRACT FROM AUTHOR]

Background Chromosome 9p21 variants are associated with cardiovascular disease (CVD) but not with any of its known risk markers. However, recent studies have suggested that the risk associated with 9p21 variation is modified by a prudent dietary pattern and smoking. We tested if the increased risk of CVD by the 9p21 single nucleotide polymorphism rs4977574 is modified by intakes of vegetables, fruits, alcohol, or wine, and if rs4977574 interacts with environmental factors on known CVD risk markers. Methods Multivariable Cox regression analyses were performed in 23,949 individuals from the population-based prospective Malm Diet and Cancer Study (MDCS), of whom 3,164 developed CVD during 15 years of follow-up. The rs4977574 variant (major allele: A; minor allele: G) was genotyped using TaqMan Assay Design probes. Dietary data were collected at baseline using a modified diet history method. Cross-sectional analyses were performed in 4,828 MDCS participants with fasting blood levels of circulating risk factors measured at baseline. Results Each rs4977574 G allele was associated with a 16% increased incidence of CVD (95% confidence interval (CI), 1.10 1.22). Higher vegetable intake (hazard ratio (HR), 0.95 [CI: 0.91 0.996]), wine intake (HR, 0.91 [CI: 0.86 0.96] ), and total alcohol consumption (HR, 0.92 [CI: 0.86 0.98]) were associated with lower CVD incidence. The increased CVD incidence by the G allele was restricted to individuals with medium or high vegetable intake (Pinteraction = 0.043), and to non- and low consumers of wine (Pinteraction = 0.029). Although rs4977574 did not associate with any known risk markers, stratification by vegetable intake and smoking suggested an interaction with rs4977574 on glycated hemoglobin and highdensity lipoprotein cholesterol (Pinteraction = 0.015 and 0.049, respectively). Conclusions Our results indicate that rs4977574 interacts with vegetable and wine intake to affect the incidence of CVD, and suggest that an interaction may exist between environmental risk factors and rs4977574 on known risk markers of CVD. [ABSTRACT FROM AUTHOR]

Background: The chromosomal locus 9p21 is a novel genetic marker for a variety of cardiovascular and cerebrovascular diseases. In a recent study, we have demonstrated an association between the single nucleotide polymorphism (SNP) rs1333040C>T on chromosome 9p21 and sporadic brain arteriovenous malformations (BAVMs). Here, we extended our analysis to an additional SNP on chromosome 9p21 (rs7865618A>G) and increased our sample size including BAVMs from two different Italian neurosurgical centers. Methods: We studied 206 patients with sporadic BAVMs and 171 unaffected controls. Genomic DNA was isolated from peripheral blood and the rs1333040C>T and rs7865618A>G polymorphisms were assessed by PCR-RFLP using the BsmI and MspI restriction endonucleases, respectively. For each SNP, we performed dominant, recessive, and additive genetic models. Results: The distribution of the three possible genotypes of rs1333040 (TT, TC and CC) was statistically different between cases and controls (p = 0.0008). The TT genotype was significantly associated with BAVMs both in the dominant (p = 0.013) and recessive (p = 0.012) models. The T allele was significantly associated with BAVMs in the additive model (p = 0.002). Also the distribution of the three possible genotypes of rs7865618 (GG, AG and AA) was statistically different between cases and controls (p = 0.005), and the GG genotype and G allele were significantly associated with BAVMs in the dominant (p = 0.032), recessive (p = 0.007), and additive models (p = 0.009). We also detected a significant association between BAVMs with large nidus size and the GG genotype and G allele of rs7865618 and the TT genotype of rs1333040. A deep venous drainage was instead associated with the TT genotype of the rs1333040 and the GG genotype of the rs7865618. The occurrence of bleeding was associated with the TT genotype and T allele of rs1333040, while the presence of seizures appeared associated with the GG genotype of rs7865618. Conclusions: SNPs of the 9p21 region, in addition to be genetic markers for coronary artery disease, stroke, and intracranial aneurysms, are associated with sporadic BAVMs. These results extend and strengthen the role of the 9p21 chromosomal region as a common risk factor for cerebrovascular diseases. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Highlights: [•] The tumor suppressor gene CDKN2B is highly expressed in human adipose tissue. [•] Risk alleles at the 9p21 locus modify CDKN2B expression in a BMI-dependent fashion. [•] There is an inverse relationship between expression of CDKN2B and adipogenic genes. [•] CDKN2B expression influences to postprandial triacylglycerol clearance. [•] CDKN2B expression in adipose tissue is linked to markers of hepatic steatosis. [Copyright &y& Elsevier]

Objectives To evaluate the proportion of cardiovascular disease ( CVD) incidence that is explained by genetic variation at chromosome 9p21 and to test whether such variation adds incremental information with regard to CVD prediction, beyond traditional risk factors. Design, setting and participants rs4977574 on chromosome 9p21 was genotyped in 24 777 subjects from the Malmö Diet and Cancer study who were free from CVD prior to the baseline examination. Association between genotype and incident CVD ( n = 2668) during a median follow-up of 11.7 years was evaluated in multivariate Cox proportional hazard models. Analyses were performed in quartiles of baseline age, and linear trends in effect size across age groups were estimated in logistic regression models. Results In additive models, chromosome 9p21 significantly predicted CVD in the entire population (hazard ratio 1.17 per G allele, 95% confidence interval 1.11-1.23, P < 0.001). Effect estimates increased from the highest (Q4) to the lowest quartile (Q1) of baseline age, but this trend was not significant. The overall population attributable risk conferred by chromosome 9p21 in fully adjusted models was 13%, ranging from 17% in Q1 to 11% in Q4. Addition of chromosome 9p21 to traditional risk factors only marginally improved predictive accuracy. Conclusion The high population attributable risk conferred by chromosome 9p21 suggests that future interventions interfering with downstream mechanisms of the genetic variation may affect CVD incidence over a broad range of ages. However, variation of chromosome 9p21 alone does not add clinically meaningful information in terms of CVD prediction beyond traditional risk factors at any age. [ABSTRACT FROM AUTHOR]

Metabolic syndrome (MetS) is a common multifactorial disorder that involves abdominal obesity, dyslipidemia, hypertension, and hyperglycemia. Genome-wide association studies have identified a major risk locus for coronary artery disease and myocardial infarction on chromosome 9p21. Here, we examined the frequency of single nucleotide polymorphisms (SNPs) on chromosome 9p21 in a sample of Turkish patients with MetS and further investigated the correlation between regional SNPs, haplotypes, and MetS. The real-time polymerase chain reaction (RT-PCR) was used to analyze 4 SNPs (rs10757274 A/G, rs2383207 A/G, rs10757278 A/G, rs1333049 C/G) in 291 MetS patients and 247 controls. Analysis of 4 SNPs revealed a significant difference in the genotype distribution for rs2383207, rs10757278, and rs1333049 between MetS patients and controls ( p = 0.041, p = 0.005, p = 0.023, respectively) but not for rs10757274 ( p = 0.211). MetS and control allelic frequencies for rs2383207, rs10757278, and rs1333049 were statistically different ( p < 0.05). The rs2383207 AG variant, was identified as a MetS risk factor ( p = 0.012, OR = 33.271; 95 % CI: 2.193-504.805) and the AA haplotype in block 1 and the GC, AG haplotypes in block 2 were associated with MetS ( χ = 3.875, p = 0.049; χ = 9.334, p = 0.0022; χ = 9.134, p = 0.0025, respectively). In this study, we found that chromosome 9p21 SNP rs10757278 and related haplotypes correlate with MetS risk. This is the first report showing an association between a 9p21 variant and MetS and suggests that rs10757278 polymorphism may confer increased risk for disease. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: A number of studies reported on associations of single nucleotide polymorphisms (SNPs) present in chromosome 9p21 with early-onset coronary artery disease (CAD). The present study was then undertaken to perform a meta-analysis of all the results published to date. Methods: All studies of the 9p21 association with early-onset CAD that were published between 2007 and 2012 were retrieved from the PubMed database. RevMan 5.0 software was used to perform meta-analysis of the data that fulfilled the criteria for our meta-analysis. The effect size of four SNPs in the 9p21 region on early-onset CAD risk was assessed based on the odds ratios (ORs) with calculation of 95% confidence interval (CI). Results: A total of 7123 subjects from 7 case–control studies were genotyped. Meta-analysis demonstrated disease association for rs2383207 (OR=0.79, 95% CI 0.71–0.88, P <0.0001), rs2383206 (OR=1.17, 95% CI 1.10–1.25, P <0.00001), rs10757278 (OR=1.28, 95% CI 1.15–1.42, P <0.00001), and rs10757274 (OR=1.17, 95% CI 1.08–1.33, P =0.02). Conclusion: Genetic variation in the chromosome 9p21 region may contribute to the etiology of early-onset CAD although their effect size is rather small. [Copyright &y& Elsevier]

Abstract: Background and aims: Genome-Wide Association Studies found some variants on chromosome 9p21 associated with type 2 diabetes (T2D). We performed a meta-analysis to estimate strength, accuracy and feature of the association of polymorphisms in 9p21 with T2D. Methods and results: Articles were retrieved screening electronic databases and cross references. Twenty-two publications were identified, for a total of 38,455 T2D patients and 60,516 controls. Twenty-one studies investigated the role of the SNP rs10811661; in some studies three additional SNPs (rs564398, rs10757278, rs1333040) were genotyped. Population attributable risk (PAR) was computed as: risk allele frequency∗(OR-1)/OR, using the per-allele odds ratio (OR). The risk allele (T) of rs10811661 was associated with T2D in most of the studies. In meta-analysis the overall per-allele OR was 1.24 (95% CI: 1.21–1.27; P < 10−15), with no difference according to ethnicity (P = 0.45), and low heterogeneity (P = 0.040) across studies partly explained by sample size. Modeling of inheritance suggested an additive effect of the T allele. PAR of T2D related to this polymorphism was 15% for Caucasians and 13% for Asians. The overall odds ratio for the T allele of the SNP rs564398 was 1.08 (95% CI: 1.05–1.12; PAR = 6%). The other SNPs showed negligible associations. Conclusions: This meta-analysis provides accurate and comprehensive estimates of the association of some genetic variants at chromosome 9p21 and T2D. A relatively small but significant role of the T allele of the rs10811661 SNP in increasing by 21–27% the risk of T2D in an additive way was apparent. [Copyright &y& Elsevier]

Abstract: Genome-wide association studies (GWAS) have identified genetic variants contributing to the risk of cardiovascular disease (CVD) at the chromosome 9p21 locus. The CVD-associated region is adjacent to the two cyclin dependent kinase inhibitors (CDKN)2A and 2B and the last exons of the non-coding RNA, ANRIL. It is still not clear which of or how these transcripts are involved in the pathogenesis of atherosclerosis. Objective: We assessed the hypothesis that 9p21 locus polymorphisms influence the expression of the transcripts in the region (ANRIL, CDKN2A/B) and that these transcripts contribute to atherogenesis through the modulation of proliferation in VSMC. Methods: We genotyped 18 SNPs (r 2 <0.8 and MAF>0.05) across the region of interest: CDKN2A/B and ANRIL, encompassing the CVD-associated region. RNA and DNA were extracted from the blood of 57 volunteers (69–72years old). Carotid ultrasound was performed in 56 subjects. CDKN2A/B and ANRIL (exons 1–2 and 17–18) expression was measured employing RT-PCR. Gene expression and cell growth were evaluated in cultured VSMC after the siRNA-mediated knock-down of ANRIL. Results: The risk alleles for atherosclerosis-related phenotypes were consistently associated with a lower expression of ANRIL when evaluating exons 1–2. Common carotid artery stenosis was associated with a significantly lower (P <0.01) expression of ANRIL (exons 1–2). ANRIL knock-down in VSMC caused significant variation in expression of CDKN2A/B (P <0.05) and reduction of cell growth (P <0.05) in vitro. Conclusion: Disease-associated SNPs at the 9p21 locus predominantly affect the expression of ANRIL. Overall, our results suggest that several CVD-associated SNPs in the 9p21 locus affect the expression of ANRIL, which, in turn modulate cell growth, possibly via CDKN2A/B regulation. [Copyright &y& Elsevier]

Background: We investigated whether 9p21 polymorphisms are associated with cardiovascular events in a group of 611 patients enrolled in the Medical, Angioplasty or Surgery Study II (MASS II), a randomized trial comparing treatments for patients with coronary artery disease (CAD) and preserved left ventricular function. Methods: The participants of the MASS II were genotyped for 9p21 polymorphisms (rs10757274, rs2383206, rs10757278 and rs1333049). Survival curves were calculated with the Kaplan-Meier method and compared with the log-rank statistic. We assessed the relationship between baseline variables and the composite end-point of death, death from cardiac causes and myocardial infarction using a Cox proportional hazards survival model. Results: We observed significant differences between patients within each polymorphism genotype group for baseline characteristics. The frequency of diabetes was lower in patients carrying GG genotype for rs10757274, rs2383206 and rs10757278 (29.4%, 32.8%, 32.0%) compared to patients carrying AA or AG genotypes (49.1% and 39.2%, p = 0.01; 52.4% and 40.1%, p = 0.01; 47.8% and 37.9%, p = 0.04; respectively). Significant differences in genotype frequencies between double and triple vessel disease patients were observed for the rs10757274, rs10757278 and rs1333049. Finally, there was a higher incidence of overall mortality in patients with the GG genotype for rs2383206 compared to patients with AA and AG genotypes (19.5%, 11.9%, 11.0%, respectively; p = 0.04). Moreover, the rs2383206 was still significantly associated with a 1.75-fold increased risk of overall mortality (p = 0.02) even after adjustment of a Cox multivariate model for age, previous myocardial infarction, diabetes, smoking and type of coronary anatomy. Conclusions: Our data are in accordance to previous evidence that chromosome 9p21 genetic variation may constitute a genetic modulator in the cardiovascular system in different scenarios. In patients with established CAD, we observed an association between the rs2383206 and higher incidence of overall mortality and death from cardiac causes in patients with multi-vessel CAD. [ABSTRACT FROM AUTHOR]

Genetic variants on chromosome 9p21 confer a robust risk for coronary artery disease but inconsistent risk for stroke. This study investigated whether such genetic variants exert differential risks on myocardial infarction (MI) and ischemic stroke in a Taiwanese population.The study recruited 425 MI patients, 687 patients with ischemic stroke, and 1377 healthy controls. Four key single nucleotide polymorphisms (SNPs) on chromosome 9p21 were genotyped.Multivariate permutation analyses demonstrated that the risk T allele of rs1333040 and G allele of rs2383207 were associated with MI (P = 0.045 and 0.002, respectively). Subjects with the rs2383207 GG genotype had a 1.85-fold (P = 0.021) risk for MI when compared with the subjects with the AA genotype. Further analysis showed that significant results only exist in the young MI group (<65 years) but not in the old MI group (≥65 years). These SNPs were not statistically significant for stroke (adjusted P ranged from 0.097 to 0.540). Haplotype analysis showed global P values of 0.032 for MI and 0.290 for stroke.Genetic variations in the 9p21 region are associated with MI but not with stroke in a Taiwanese population. Early-onset MI was more likely to carry the risk genotypes of 9p21 SNPs. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Sequence variation at Ch9p21 is a predisposing genetic factor for a number of diseases, including myocardial infarction (MI) and diabetes. We determined the risk of MI associated with various alleles and haplotypes, established and compared the predictive values of risk alleles, tested for the independence of associations between different risk alleles and MI, and sought to provide evidence for dual association of alleles with MI and diabetes. Methods: With the use of 35 single nucleotide polymorphisms, together capturing common variation seen in the associated interval, we genotyped 3657 MI cases and 1211 controls prospectively sampled in a European population. Results: Polymorphisms rs10757278 and rs1333049 both exhibited the strongest individual risk signal (OR, 1.45; 95% CI, 1.32–1.59). Two haplotype blocks were established, each of which was mainly represented by a pair of a risk-conferring and a protective haplotype, but none of the risk-associated haplotypes exhibited stronger effects than rs10757278 or rs1333049 alone. Specific polymorphisms (rs7865618, rs1537378, rs7857345, rs1333049) were identified as independent predictors of MI in multivariable models adjusted for conventional cardiovascular risk factors. In specific instances, the presence of two or three polymorphisms in a model, instead of only one, improved the discriminating power. Finally, evidence was provided to suggest dual association of rs7865618 with MI and diabetes. Conclusion: In keeping with published results, this work was consistent with the association of alleles and haplotypes at Ch9p21 with MI and extended prior knowledge by also showing independence of associations among different risk alleles and an association of a specific polymorphism with both MI and diabetes. [Copyright &y& Elsevier]

Recent genome-wide association studies have demonstrated that common genetic variants in a region of chromosome 9p21 confer risk of coronary artery disease (CAD) and other atherosclerotic conditions. Although the absolute increase in risk is small (some 20-30% increase in risk of CAD per copy of the deleterious alleles), the common occurrence of the variants means that their effect on the population risk of disease is estimated to be substantial. Studies investigating the relationship between risk variants and both 'classical' and 'emerging' atherosclerotic risk factors have found no evidence of association. This suggests that the effect of the 9p21 locus on atherosclerotic risk is mediated via a hitherto unknown pathway potentially amenable to therapeutic modulation. Investigation of potential disease mechanisms at this locus is therefore a focus of intense interest. In this review, we discuss the progress that has been made in the study of mechanisms and highlight the outstanding research questions. [ABSTRACT FROM AUTHOR]

The article focuses on a study which investigated the association of chromosome 9p21 haplotypes with increased risk for adverse cardiovascular outcomes in patients diagnosed with coronary artery disease (CAD). It explains experimental and epidemiological evidence indicating the occurrence of CAD from a combination of environmental and genetic factors. It discusses the outcomes of various study analyses such as the International Verapamil SR Trandolapril Study (INVEST) and the Investigation of outcomes From Acute Coronary Syndromes Study (INFORM).

Abstract: Objective: The pathophysiology underlying the chromosome (Chr) 9p21 locus of atherosclerosis susceptibility is presently unknown. Here, we sought to determine whether protein coding genes in the Chr9p21 region, i.e. cyclin-dependent kinase inhibitors CDKN2B (p15INK4b), CDKN2A (p16INK4a, p14ARF) and methylthioadenosine phosphorylase (MTAP) were expressed in human atherosclerotic lesions and whether expression was correlated with lesion composition. Methods and results: Protein expression of p15INK4b, p16INK4a, p14ARF and MTAP was demonstrated by immunostaining in normal and atherosclerotic coronary arteries and co-localized with CD68 and smooth muscle alpha-actin positive cells. Quantitative RT-PCR in human endarteryectomy specimens (n =57) revealed increased p16 INK4a and decreased MTAP expression in macrophage-rich lesions (P <0.001 and P =0.007, respectively). Functional studies suggest that decreased MTAP expression in macrophage-rich lesions might be mediated through down-regulation by TNF-alpha. No clear association of p15 INK4b , p16 INK4a , p14 ARF , and MTAP expression in plaque tissue with Chr9p21 haplotypes was found. The latter finding was corroborated by the lack of correlation of RNA expression of 9p21-regulated transcripts EU741058 and NR_003529 of antisense non-coding RNA in the INK4 locus (ANRIL) with mRNA expression of these genes. In contrast, ANRIL DQ485454 which is not genetically determined by the 9p21 genotype was significantly correlated with MTAP expression (P =0.01). Conclusion: CDKN2B (p15INK4b), CDKN2A (p16INK4a, p14ARF), and MTAP are abundantly expressed in atherosclerotic lesions. While expression levels showed no clear association with Chr9p21 genotype, association of high p16 INK4a and low MTAP expression with a less stable plaque phenotype suggests a more general role of these proteins in atherogenesis. [Copyright &y& Elsevier]

Chromosome 9p21 has been implicated in the pathogenesis of cutaneous malignant melanoma (CMM). In addition to CDKN2A, the major known high-risk susceptibility gene for CMM, recent studies suggest that other 9p21 genes may be involved in melanoma/nevi development. To identify 9p21 variants that influence susceptibility to CMM and number of nevi in CMM-prone families with and without CDKN2A mutations, we analyzed 562 individuals (183 CMM) from 53 families (23 CDKN2A+, 30 CDKN2A−) for 233 tagging SNPs in 21 genes at 9p21. Single SNP- and gene-based regression analyses were used to assess the risk of CMM, nevi count, skin complexion, and tanning ability associated with these SNPs and genes. We found that SNP rs7023329 in the MTAP gene was associated with number of nevi ( P = 0.003) confirming a recent finding by a genome-wide association study. In addition, three SNPs in the ACO1 gene, rs7855483 ( P = 0.002), rs17288067 ( P = 0.0009), and rs10813813 ( P = 0.005), showed the strongest associations with CMM risk. None of the examined 9p21 SNPs was associated with skin complexion, whereas two SNPs, rs10964862 in IFNW1 ( P = 0.003), and rs13290968 in TUSC1 ( P = 0.0006), were associated with tanning ability. Gene-based analyses suggested that the ACO1 gene was significantly associated with CMM ( P = 0.0004); genes IFNW1 ( P = 0.002) and ACO1 ( P = 0.0002) were significantly associated with tanning ability. Our findings are consistent with recent proposals that additional 9p21 genes may contribute to CMM susceptibility in CMM-prone families. These genetic variants may, at least partially, exert their effects through nevi and tanning ability. [ABSTRACT FROM AUTHOR]

Aims: Recent genetic studies identified the rs1333049 variant on chromosome 9p21 as a major susceptibility locus for coronary artery disease and myocardial infarction (MI). Here, we evaluated whether this variant also contributes to recurrent MI or cardiac death following an acute coronary syndrome (ACS). [ABSTRACT FROM PUBLISHER]

Meningioangiomatosis (MA) is a rare lesion appearing sporadically or as a part of neurofibromatosis 2. The occurrences of meningiomas arising from MA (MA-M) have raised doubts about the traditional concept of a hamartomatous origin for MA. Cytogenetic or molecular studies on MA, with or without meningiomas, are limited because of the rarity of MA. The current study was to evaluate the loss of heterozygosity (LOH) in seven cases of MA-M and two cases of pure MA. LOH on six chromosomes (1p32, 9p21, 13q14, 16q22, 17p, and 22q12) were investigated using 13 sets of microsatellite markers, including D1S193, D1S463, D22S193, D22S929, D22S282, TP53, D17S796, D16S421, D16S512, D13S118, D13S153, D9S162, and D9S104. PCR was performed using each marker and polymorphic analysis was accomplished by silver staining. Immunohistochemical stain for Ki-67 was carried out and labeling index was measured by using a semiquantitative manual counting method. The meningioma portions of MA-Ms showed LOH for loci on chromosomes 22q12, 9p21, and 1p32 in 57.1% (4/7), 28.6% (2/7), and 28.6% (2/7) of cases, respectively. The MA portions of MA-M had a LOH for loci on 22q12 in 28.6% (2/7) of cases, whereas each pure MA harbored one LOH on either chromosome 22q12 or 9p21. The proliferation indices of MA-Ms were significantly higher in the meningioma than in the MA components. Our data suggest that both the meningioma and the MA undergo the same overlapping clonal process, with the MA-M while undergoing additional genetic alterations that confer a greater proliferative potential. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Recent large-scale genome-wide association studies have identified a novel susceptibility locus on chromosome 9p21.3 that contributes a significant attributable risk for myocardial infarction. The phenotypic significance of this locus in patients with established coronary artery disease is unknown. We sought to compare cardiovascular structure and function in carriers and non-carriers of the risk haplotype in a cross-sectional study. Methods: We genotyped the rs1333049 single-nucleotide polymorphism in 593 Caucasian individuals with stable coronary artery disease recruited in the Heart and Soul Study. All study subjects underwent resting and stress echocardiography. Linear and logistic regression models were used to examine the association between the rs1333049 polymorphism and echocardiographic parameters of cardiovascular structure and function. Results: There was no association between rs1333049 genotype and echocardiographic phenotype (left ventricular hypertrophy, systolic dysfunction, diastolic dysfunction, inducible ischemia, exercise capacity, mitral annular calcification, and aortic plaque). Conclusions: In a cross-sectional study of individuals with stable coronary artery disease, there was no association of chromosome 9p21.3 genotype with cardiovascular structure and function. [Copyright &y& Elsevier]

Summary: Cholangiocarcinoma in northeast Thailand is associated with liver fluke infection. Mechanisms of inactivation of the p15 INK4b , p16 INK4a , and p14 ARF have been reported in many human cancers but have not hitherto been studied in liver fluke–related cholangiocarcinoma, particularly genetic and epigenetic effects on protein expression. We investigated loss of heterozygosity and microsatellite instability and performed fine mapping of the chromosomal region 9p21-pter in 94 microdissected cholangiocarcinoma samples using polymerase chain reaction based–microsatellite markers. Methylation and protein expression of p14 ARF , p15 INK4b , and p16 INK4a was determined using methylation-specific polymerase chain reaction and immunohistochemistry, respectively. Genetic and epigenetic alterations, including loss of protein expression, were correlated with clinicopathological data. Fine mapping at 9p21-pter showed a distinctive region between D9S286 and D9S1752 of common loss. Methylation frequency was 40.2% for p14 ARF , 48.9% for p15 INK4b , and 28.3% for p16 INK4a . Loss of protein expression of p14ARF, p15INK4b, and p16INK4a was 30.9%, 58%, and 81.5%, respectively. Both p14 ARF methylation and allelic loss at 9p21 were associated with loss of p14ARF expression. Poor prognosis was associated with loss of p16INK4a expression. In conclusion, mechanisms of inactivation of p14 ARF , p15 INK4b , and p16 INK4a in liver fluke–related cholangiocarcinoma are preferentially different, by which epigenetic event being the main mechanism of p14 ARF , whereas p16 INK4a and p15 INK4b inactivation occurs through genetic and both genetic and epigenetic events, respectively. [Copyright &y& Elsevier]

Abdominal aortic aneurysm (AAA) is among a number of vascular disorders to be recently associated with a common allelic variant situated on chromosome 9p21. To further assess the significance of this region of the genome in AAA development, we genotyped the sequence variation tagged by rs10757278 in two geographically independent cohorts of patients and compared them to matched controls. We also assessed the impact of this variant on AAA growth rate in cohorts with a median surveillance period of 3.2 and 4.5 years. Using meta-analysis to combine the findings of both cohorts, we found a significant association between rs10757278-G and the presence of AAA (OR (95%CI) 1.38 (1.04–1.82) P=0.03), an effect size completely consistent with that originally reported. rs10757278 was not significantly associated with altered AAA growth rate in either cohort.European Journal of Human Genetics (2009) 17, 391–394; doi:10.1038/ejhg.2008.196; published online 15 October 2008 [ABSTRACT FROM AUTHOR]

Genome-wide single nucleotide polymorphism (SNP) association studies recently identified four SNPs (rs10757274, rs2383206, rs2383207, and rs10757278) on chromosome 9p21 that were associated with coronary artery disease (CAD) and myocardial infarction (MI) in Caucasian populations from northern Europe and North America. Our aim was to determine whether these SNPs were associated with MI in a southern Europe/Mediterranean population. We employed a case–control association design involving 416 MI patients and 308 non-MI controls from Italy. Significant allelic association was identified between all four SNPs and MI. The association remained significant after adjusting for covariates for MI ( P = 0.007–0.029). One risk haplotype (GGGG; P = 0.028) and one protective haplotype (AAAA; P = 0.047) were identified. Genotypic association analysis demonstrated that the SNPs conferred susceptibility to MI most likely in a dominant model ( P = 0.0007–0.013). When the case cohort was divided into a group of MI patients with a family history ( n = 248) and one group without it ( n = 168), the positive, significant association was identified only in the group with the family history. These results indicate that chromosome 9p21 confers risk for development of MI in an Italian population. [ABSTRACT FROM AUTHOR]

Background The chromosome 9p21 and its CDKN locus, with the p16 tumour suppressor gene ( CDKN2A), are recognized as the genomic regions involved in the pathogenesis of melanoma. Objectives To elucidate further the role of such regions during the different phases of melanocytic tumorigenesis. Methods Tissue sections from naevi, primary and metastatic melanomas were investigated by fluorescence in situ hybridization for allelic loss at the 9p21 chromosome and by immunochemistry for p16CDKN2A expression. Results Dysplastic naevi and primary or secondary melanomas were found to carry hemizygous deletions within the entire 9p21 region at similar frequencies (varying from 55% to 62%). Allelic deletion spanning the CDKN locus was observed at significantly increased rates moving from early (7%) to advanced (28%) primary melanomas and to secondary melanoma lesions (37%) ( P = 0·018). Also, inactivation of the p16 gene ( CDKN2A) was absent in naevi and present at steadily increasing rates moving from primary melanomas (7% early lesions to 17% advanced lesions) to melanoma metastases (62%) ( P = 0·004). Conclusions Our findings indicate that, in a model of sequential accumulation of genetic alterations, 9p21 deletions may play a role in melanocytic transformation and tumour initiation whereas rearrangements at the CDKN locus, and p16 gene ( CDKN2A) inactivation may contribute to tumour progression. [ABSTRACT FROM AUTHOR]

Homozygous deletions of the tumor suppressor gene p16INK4A and deficiency of methylthioadenosine phosphorylase (MTAP), both located on chromosome 9p21, have been independently reported in non-small cell lung cancer (NSCLC). To determine the frequency of co-deletion of these two genes, we investigated 50 samples of primary NSCLC using a quantitative PCR-ELISA. All specimens were fixed in formalin, paraffin embedded and stored until assayed. Histologic subtypes included 25 adenocarcinomas (50%), 21 squamous cell carcinomas (42%) and four large cell carcinomas (8%). Homozygous deletions of MTAP exon 8 could be detected in 19 of 50 NSCLC samples (38%). Adenocarcinoma (11 of 25, 44%) showed a higher deletion frequency than squamous cell carcinoma (six of 21, 29%). In contrast, homozygous p16INK4A deletions were detected in only nine of 50 (18%) samples using specific primers for p16INK4A exon 1α. No difference between the histological subtypes and p16INK4A deletion frequency was observed. We further investigated the ten samples with MTAP deletions but intact p16INK4A exon 1α with primers specific for p16INK4A exon 3, the exon nearest to MTAP exon 8. Interestingly, none of the ten samples had deletion of the p16INK4A exon 3 coding region. Fine mapping analysis performed in ten samples showed a frequent breakpoint between MTAP exon 4 and exon 5. In addition, p16 protein expression could not be detected in five out of six samples with intact p16 but deleted MTAP locus. These data show a high frequency of homozygous MTAP deletions in NSCLC which is associated with detectable co-deletion of p16INK4A in only half of the cases. This result suggests the existence either of another tumor suppressor gene telomeric of p16INK4A or of deletions involving 3′-untranslated (3′-UTR) regulatory regions of p16INK4A that can interfere with its expression or function. [ABSTRACT FROM AUTHOR]

Serous borderline tumors (SBT) are the most common subtype of ovarian borderline tumors with excellent clinical course. However, they can recur or progress to low-grade serous carcinoma (LGSC) in a small proportion of the cases. Beside BRAF and KRAS mutations, copy number alterations (CNA), particularly loss of chromosome 9p21 locus which results in deletion of genes CDKN2A and MTAP, have been suggested to be involved in disease progression. MTAP immunohistochemistry recently has been introduced for mesothelioma as a reliable surrogate marker for the homozygous deletion of chromosome 9p21 locus. Therefore, in the current study, we aimed to evaluate the MTAP loss of expression in serous borderline tumors and low-grade serous carcinomas to identify if it can be used as a marker for prognosis and progression. Eighty-four total cases of ovarian serous lesions, including 21 cases of serous cystadenomas, 21 cases of serous borderline tumors, 12 cases of low-grade serous carcinomas and 30 cases of high-grade serous carcinomas were selected. MTAP immunohistochemistry was performed on the representative blocks and cytoplasmic staining was used for interpretation. The cases were labeled as positive (retained) if MTAP showed cytoplasmic granular staining and negative (loss of expression) if negative cytoplasmic staining was observed in the presence of positive internal control. Ten of 21 cases of serous borderline tumors showed loss of MTAP expression (48%). Among those, 7 cases were bilateral, 2 cases had micropapillary features, one case had supraclavicular and cervical lymph node involvement by serous borderline tumor and 2 cases had progression to low-grade serous carcinoma, including one of micropapillary tumors. Also 8 out of 12 cases of LGSCs showed MTAP loss of expression (66%). Only 4 of 30 cases of high-grade serous carcinomas (13%) and none of the serous cystadenoma cases showed loss of expression of MTAP. To our knowledge, this is the first description of MTAP immunohistochemistry in serous borderline tumors and low-grade serous carcinomas. Our study was limited due to small sample size. However, it showed an association between MTAP loss of expression and adverse clinical behavior in ovarian serous borderline tumors. This supports the role for further investigations in larger series to evaluate the role of MTAP stain as a prognostic marker in these neoplasms. • Loss of chromosome 9p21 locus may play role in progression of ovarian serous borderline tumors (SBT) to low grade serous carcinoma. • Loss of MTAP expression can serve as a surrogate marker for homozygous deletions of chromosome 9p21. • MTAP immunohistochemistry may serve as a useful prognostic marker to identify SBTs with higher risk of recurrence and progression. [ABSTRACT FROM AUTHOR]