Clinical and genetic characteristics of ankylosing spondylitis patients with peripheral arthritis at disease onset.

OBJECTIVES: The aim of this study was to assess the clinical and genetic characteristics associated with the presence of peripheral arthritis (PA) at disease onset in patients with ankylosing spondylitis (AS). METHODS: 456 Spanish AS patients, diagnosed according to the modified New York Criteria, who had at least ten years of follow-up since initial disease onset were selected from the National Spondyloarthropathies Registry (REGISPONSER). 18.9% of AS patients initially presented PA. Clinical variables and 384 single nucleotide polymorphisms (SNPs) distributed in 190 genes were analysed. SNP genotyping was performed using the Illumina GoldenGate genotyping platform. Association tests for allele frequencies and for categorical clinical variables were performed by the χ2 test and with the unpaired t-test for continuous variables. p-values of <0.05 were considered statistically significant. RESULTS: AS patients with PA showed an earlier age of disease onset (p=0.021), longer disease duration (p=0.020) and longer duration of AS symptoms from onset (p=0.034) than AS patients without PA. We found significant associations with the presence of PA at disease onset in 14 SNPs located in 10 genes: HLA-DQB2 (rs2857210 and rs9276615), HLA-DOB (rs2857151, rs2621332 and rs1383261), JAK2 (rs7857730), IL-23R (rs11209008 and rs10489630), CYP1B1 (rs1056836), NELL1 (rs8176786), KL (rs564481), and MEFV (rs224204), IL-2RB (rs743777) and IL-1A (rs1800587). CONCLUSIONS: Both clinical and genetic factors are associated with the presence of PA at disease onset in Spanish AS patients. The results suggest that this subset of AS patients with PA at disease onset might have differentiation factors involved in disease pathogenesis.

Pathogenic classification of LPL gene variants reported to be associated with LPL deficiency.

BACKGROUND: Lipoprotein lipase (LPL) deficiency is a serious lipid disorder of severe hypertriglyceridemia (SHTG) with chylomicronemia. A large number of variants in the LPL gene have been reported but their influence on LPL activity and SHTG has not been completely analyzed. Gaining insight into the deleterious effect of the mutations is clinically essential. METHODS: We used gene sequencing followed by in-vivo/in-vitro and in-silico tools for classification. We classified 125 rare LPL mutations in 33 subjects thought to have LPL deficiency and in 314 subjects selected for very SHTG. RESULTS: Of the 33 patients thought to have LPL deficiency, only 13 were homozygous or compound heterozygous for deleterious mutations in the LPL gene. Among the 314 very SHTG patients, 3 were compound heterozygous for pathogenic mutants. In a third group of 51,467 subjects, from a general population, carriers of common variants, Asp9Asn and Asn291Ser, were associated with mild increase in triglyceride levels (11%-35%). CONCLUSION: In total, 39% of patients clinically diagnosed as LPL deficient had 2 deleterious variants. Three patients selected for very SHTG had LPL deficiency. The deleterious mutations associated with LPL deficiency will assist in the diagnosis and selection of patients as candidates for the presently approved LPL gene therapy.

A genetic predictive model for canine hip dysplasia: integration of Genome Wide Association Study (GWAS) and candidate gene approaches.

Canine hip dysplasia is one of the most prevalent developmental orthopedic diseases in dogs worldwide. Unfortunately, the success of eradication programs against this disease based on radiographic diagnosis is low. Adding the use of diagnostic genetic tools to the current phenotype-based approach might be beneficial. The aim of this study was to develop a genetic prognostic test for early diagnosis of hip dysplasia in Labrador Retrievers. To develop our DNA test, 775 Labrador Retrievers were recruited. For each dog, a blood sample and a ventrodorsal hip radiograph were taken. Dogs were divided into two groups according to their FCI hip score: control (A/B) and case (D/E). C dogs were not included in the sample. Genetic characterization combining a GWAS and a candidate gene strategy using SNPs allowed a case-control population association study. A mathematical model which included 7 SNPs was developed using logistic regression. The model showed a good accuracy (Area under the ROC curve = 0.85) and was validated in an independent population of 114 dogs. This prognostic genetic test represents a useful tool for choosing the most appropriate therapeutic approach once genetic predisposition to hip dysplasia is known. Therefore, it allows a more individualized management of the disease. It is also applicable during genetic selection processes, since breeders can benefit from the information given by this test as soon as a blood sample can be collected, and act accordingly. In the authors' opinion, a shift towards genomic screening might importantly contribute to reducing canine hip dysplasia in the future. In conclusion, based on genetic and radiographic information from Labrador Retrievers with hip dysplasia, we developed an accurate predictive genetic test for early diagnosis of hip dysplasia in Labrador Retrievers. However, further research is warranted in order to evaluate the validity of this genetic test in other dog breeds.

Improved prediction of knee osteoarthritis progression by genetic polymorphisms: the Arthrotest Study.

OBJECTIVE: The aim of this study was to develop a genetic prognostic tool to predict radiographic progression towards severe disease in primary knee OA (KOA) patients. METHODS: This investigation was a cross-sectional, retrospective, multicentric association study in 595 Spanish KOA patients. Caucasian patients aged ≥40 years at the time of diagnosis of primary KOA of Kellgren-Lawrence grade 2 or 3 were included. Patients who progressed to Kellgren-Lawrence score 4 or who were referred for total knee replacement within 8 years after diagnosis were classified as progressors to severe disease. Clinical variables of the initial stages of the disease (gender, BMI, age at diagnosis, OA in the contralateral knee, and OA in other joints) were registered as potential predictors. Single nucleotide polymorphisms and clinical variables with an association of P < 0.05 were included in the multivariate analysis using forward logistic regression. RESULTS: A total of 23 single nucleotide polymorphisms and the time of primary KOA diagnosis were significantly associated with KOA severe progression in the exploratory cohort (n = 220; P < 0.05). The predictive accuracy of the clinical variables was limited: area under the curve (AUC) = 0.66. When genetic variables were added to the clinical model (full model), the prediction of KOA progression was significantly improved (AUC = 0.82). Combining only genetic variables (rs2073508, rs10845493, rs2206593, rs10519263, rs874692, rs7342880, rs780094 and rs12009), a predictive model with good accuracy was also obtained (AUC = 0.78). The predictive ability for KOA progression of the full model was confirmed on the replication cohort (two-sample Z-test; n = 62; P = 0.190). CONCLUSION: An accurate prognostic tool to predict primary KOA progression has been developed based on genetic and clinical information from OA patients.

Candidate's single-nucleotide polymorphism predictors of treatment nonresponse to the first anti-TNF inhibitor in ankylosing spondylitis.

The objective of this study is to identify single-nucleotide polymorphisms (SNPs) predictors of treatment nonresponse to the first anti-TNF-alpha agent in ankylosing spondylitis (AS). Patients were classified as "nonresponders" if they failed to achieve improvement ≥50 % of the initial BASDAI. We selected candidate SNPs previously reported, associated with susceptibility or pathogenesis of AS and with other spondylarthropaties (SpAs). The predictors of nonresponse were modeled with multiple logistic regression. The predictive power of the genetic model of nonresponse to treatment was tested with AUC-ROC. One hundred and twenty-one (121) AS patients fulfilled the inclusion criteria. Of the candidate SNPs tested for association with treatment effectiveness, five independent predictors were identified: rs917997, rs755622, rs1800896, rs3740691, and rs1061622. The genetic model of nonresponse to treatment had a predictive power of 0.77 (95 % CI 0.68-0.86). Our study identified several polymorphisms which could be the useful genetic biomarkers in predicting nonresponse to anti-TNF-alpha therapy.

Genetic and microbial factors modulating the ubiquitin proteasome system in inflammatory bowel disease.

OBJECTIVE: Altered microbiota composition, changes in immune responses and impaired intestinal barrier functions are observed in IBD. Most of these features are controlled by proteases and their inhibitors to maintain gut homeostasis. Unrestrained or excessive proteolysis can lead to pathological gastrointestinal conditions. The aim was to validate the identified protease IBD candidates from a previously performed systematic review through a genetic association study and functional follow-up. DESIGN: We performed a genetic association study in a large multicentre cohort of patients with Crohn's disease (CD) and UC from five European IBD referral centres in a total of 2320 CD patients, 2112 UC patients and 1796 healthy controls. Subsequently, we did an extensive functional assessment of the candidate genes to explore their causality in IBD pathogenesis. RESULTS: Ten single nucleotide polymorphisms (SNPs) in four genes were significantly associated with CD: CYLD, USP40, APEH and USP3. CYLD was the most significant gene with the intronically located rs12324931 the strongest associated SNP (p(FDR)=1.74e-17, OR=2.24 (1.83 to 2.74)). Five SNPs in four genes were significantly associated with UC: USP40, APEH, DAG1 and USP3. CYLD, as well as some of the other associated genes, is part of the ubiquitin proteasome system (UPS). We therefore determined if the IBD-associated adherent-invasive Escherichia coli (AIEC) can modulate the UPS functioning. Infection of intestinal epithelial cells with the AIEC LF82 reference strain modulated the UPS turnover by reducing poly-ubiquitin conjugate accumulation, increasing 26S proteasome activities and decreasing protein levels of the NF-κB regulator CYLD. This resulted in IκB-α degradation and NF-κB activation. This activity was very important for the pathogenicity of AIEC since decreased CYLD resulted in increased ability of AIEC LF82 to replicate intracellularly. CONCLUSIONS: Our results reveal the UPS, and CYLD specifically, as an important contributor to IBD pathogenesis, which is favoured by both genetic and microbial factors.

Genetic factors conferring an increased susceptibility to develop Crohn's disease also influence disease phenotype: results from the IBDchip European Project.

OBJECTIVE: Through genome-wide association scans and meta-analyses thereof, over 70 genetic loci (Crohn's disease (CD) single nucleotide polymorphisms (SNPs)) are significantly associated with CD. We aimed to investigate the influence of CD-SNPs and basic patient characteristics on CD clinical course, and develop statistical models to predict CD clinical course. DESIGN: This retrospective study included 1528 patients with CD with more than 10 years of follow-up from eight European referral hospitals. CD outcomes of interest were ileal (L1), colonic (L2) and ileocolonic disease location (L3); stenosing (B2) or penetrating behaviour (B3); perianal disease; extraintestinal manifestations; and bowel resection. A complicated disease course was defined as stenosing or penetrating behaviour, perianal disease and/or bowel resection. Association between CD-SNPs or patient characteristics and specified outcomes was studied. RESULTS: Several CD-SNPs and clinical characteristics were statistically associated with outcomes of interest. The NOD2 gene was the most important genetic factor, being an independent predictive factor for ileal location (p=2.02 × 10(-06), OR=1.90), stenosing (p=3.16 × 10(-06), OR=1.82) and penetrating (p=1.26 × 10(-02), OR=1.25) CD behaviours, and need for surgery (p=2.28 × e-05, OR=1.73), and as such was also the strongest factor associated with a complicated disease course (p=6.86 × 10(-06), OR=2.96). Immunomodulator (azathioprine/6-mercaptopurine and methotrexate) use within 3 years after diagnosis led to a reduction in bowel stenoses (p=1.48 × 10(-06), OR=0.35) and surgical rate (p=1.71 × 10(-07), OR=0.34). Association between each outcome and genetic scores, created using significant SNPs in the univariate analysis, revealed large differences in the probability of developing fistulising disease (IL23R, LOC441108, PRDM1, NOD2; p=9.64e-4, HR=1.43), need for surgery (IRGM, TNFSF15, C13ORF31, NOD2; p=7.12 × 10(-03), HR=1.35), and stenosing disease (NOD2, JAK2, ATG16L1; p=3.01 × 10(-02), HR=1.29) among patients with low and high score. CONCLUSIONS: This large multicentre cohort study has found several genetic and clinical factors influencing the clinical course of CD. NOD2 and early immunomodulator use are the clinically most meaningful predictors for its clinical course.

Genetic predisposition to early recurrence in clinically localized prostate cancer.

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Currently available nomograms to predict preoperative risk of early biochemical recurrence (EBCR) after radical prostatectomy are solely based on classic clinicopathological variables. Despite providing useful predictions, these models are not perfect. Indeed, most researchers agree that nomograms can be improved by incorporating novel biomarkers. In the last few years, several single nucleotide polymorphisms (SNPs) have been associated with prostate cancer, but little is known about their impact on disease recurrence. We have identified four SNPs associated with EBCR. The addition of SNPs to classic nomograms resulted in a significant improvement in terms of discrimination and calibration. The new nomogram, which combines clinicopathological and genetic variables, will help to improve prediction of prostate cancer recurrence. OBJECTIVES: To evaluate genetic susceptibility to early biochemical recurrence (EBCR) after radical prostatectomy (RP), as a prognostic factor for early systemic dissemination. To build a preoperative nomogram to predict EBCR combining genetic and clinicopathological factors. PATIENTS AND METHODS: We evaluated 670 patients from six University Hospitals who underwent RP for clinically localized prostate cancer (PCa), and were followed-up for at least 5 years or until biochemical recurrence. EBCR was defined as a level prostate-specific antigen >0.4 ng/mL within 1 year of RP; preoperative variables studied were: age, prostate-specific antigen, clinical stage, biopsy Gleason score, and the genotype of 83 PCa-related single nucleotide polymorphisms (SNPs). Univariate allele association tests and multivariate logistic regression were used to generate predictive models for EBCR, with clinicopathological factors and adding SNPs. We internally validated the models by bootstrapping and compared their accuracy using the area under the curve (AUC), net reclassification improvement, integrated discrimination improvement, calibration plots and Vickers' decision curves. RESULTS: Four common SNPs at KLK3, KLK2, SULT1A1 and BGLAP genes were independently associated with EBCR. A significant increase in AUC was observed when SNPs were added to the model: AUC (95% confidence interval) 0.728 (0.674-0.784) vs 0.763 (0.708-0.817). Net reclassification improvement showed a significant increase in probability for events of 60.7% and a decrease for non-events of 63.5%. Integrated discrimination improvement and decision curves confirmed the superiority of the new model. CONCLUSIONS: Four SNPs associated with EBCR significantly improved the accuracy of clinicopathological factors. We present a nomogram for preoperative prediction of EBCR after RP.

Both baseline clinical factors and genetic polymorphisms influence the development of severe functional status in ankylosing spondylitis.

Functional severity in ankylosing spondylitis (AS) patients is variable and difficult to predict early. The aim of our study was to assess whether a combination of baseline clinical factors and genetic markers may predict the development of severe functional status in AS. We performed a cross-sectional association study on AS patients included in the Spanish National Registry of Spondyloarthropathies--REGISPONSER. Bath Ankylosing Spondylitis Functional Index (BASFI) was standardized by adjusting for disease duration since the first symptoms (BASFI/t). We considered as severe functional status the values of BASFI/t in the top of the 60th (p60), 65th (p65), 70th (p70), and 75th (p75) percentile. We selected 384 single nucleotide polymorphisms (SNPs) distributed in 190 genes to be analyzed. The study cohort included 456 patients with mean age 50.8(± 10.5) years and with mean disease duration since first symptoms 24.7 (± 10.1) years. Older age at disease onset and neck pain at baseline showed statistical significant association with severe BASFI/t. Polymorphisms associated in the allele frequencies test with severe BASFI/t in all classifications were: rs2542151 (p60 [P = .04], p65 [P = .04], p70 [P = .001] and p75 [P = .001]) and rs2254441 (p60 [P = .004], p65 [P = .02], p70 [P = .01] and p75 [P<.001]).. Genotype association, after adjustment for covariates, found an association in three of the four patients' classifications for rs2542151 and in two of the classifications for rs2254441.Forward logistic regression did not identify any model with a good predictive power for severe functional development.In our study we identified clinical factors and 24 polymorphisms associated with development of severe functional status in AS patients. Validation of these results in other cohorts is required.

Genetic polymorphisms inside and outside the MHC improve prediction of AS radiographic severity in addition to clinical variables.

OBJECTIVE: The aim of this study was to analyse if single nucleotide polymorphisms (SNPs) inside and outside the MHC region might improve the prediction of radiographic severity in AS. METHODS: A cross-sectional multi-centre study was performed including 473 Spanish AS patients previously diagnosed with AS following the Modified New York Criteria and with at least 10 years of follow-up from the first symptoms of AS. Clinical variables and 384 SNPs were analysed to predict radiographic severity [BASRI-total (BASRI-t) corrected for the duration of AS since first symptoms] using multivariate forward logistic regression. Predictive power was measured by the area under the receiver operating characteristic curve (AUC), specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: The model with the best fit measured radiographic severity as the BASRI-t 60th percentile and combined eight variables: male gender, older age at disease onset and six SNPs at ADRB1 (rs1801253), NELL1 (rs8176785) and MHC (rs1634747, rs9270986, rs7451962 and rs241453) genes. The model predictive power was defined by AUC = 0.76 (95% CI 0.71, 0.80), being significantly better than the model with only clinical variables, AUC = 0.68 (95% CI 0.63, 0.73), P = 0.0004. Internal split-sample analysis proved the validation of the model. Patient genotype for SNPs outside the MHC region, inside the MHC region and clinical variables account for 26, 38 and 36%, respectively, of the explained variability on radiographic severity prediction. CONCLUSION: Prediction of radiographic severity in AS based on clinical variables can be significantly improved by including SNPs both inside and outside the MHC region.

ERAP1 polymorphisms and haplotypes are associated with ankylosing spondylitis susceptibility and functional severity in a Spanish population.

OBJECTIVES: The aim of this study was to assess the involvement of the endoplasmic reticulum aminopeptidase 1 (ERAP1) gene in AS susceptibility and functional severity in a Spanish population. METHODS: Eight single nucleotide polymorphisms (SNPs) spanning the ERAP1 gene were genotyped by allele-specific fluorescent PCR in 300 AS Spanish patients and 300 spondylarthritis-free controls. The influence of the ERAP1 SNPs on the functional severity of AS was analysed with the BASFI corrected for disease duration. Association analyses with AS susceptibility and functional severity were performed. RESULTS: Significant ERAP1 single marker association with AS susceptibility was found for five SNPs, namely rs30187 (allele T: P = 0.035), rs17482078 (allele C: P = 0.030), rs2287987 (allele T: P = 0.028), rs26653 (allele C: P = 0.041) and rs10050860 (allele C: P = 0.018). Three of the associated SNPs (rs17482078, rs2287987 and rs10050860) were in strong linkage disequilibrium. After imputing genotypes with the HapMap CEU data as reference, the strongest association was with rs41135 (P = 0.0046) in the 5'-upstream region of ERAP1. In addition, the SNP rs17481856 was found to be a risk factor for functional severity in AS and a borderline trend was observed for rs27044. CONCLUSIONS: These results suggest that the ERAP1 gene is associated with genetic predisposition to AS and influences the functional severity of the disease in a Spanish population.

Trp64Arg polymorphism in ADRB3 gene is associated with elite endurance performance.

In this study, allele and genotype frequencies of the ADRB1 Arg389Gly (rs1801253), ADRB2 Gly16Arg (rs1042713) and Gln27Glu (rs1042714), and ADRB3 Trp64Arg (rs4994) variations were compared in the following three groups of Spanish (Caucasian) men: (1) world-class endurance athletes (E; runners and cyclists, n=100), (2) elite power athletes (P; sprinters, jumpers and throwers, n=53) and (3) non-athletic controls (C; n=100). No significant differences were observed in genotype and allele distributions among the study groups except for the ADRB3 Trp64Arg polymorphism in E versus C (27% vs 8% of carriers of the Arg allele in E and C, p<0.001; frequency of the minor Arg (C) allele of 14% vs 4% in E and C, p=0.001). Heterozygosity for the ADRB3 Trp64Arg polymorphism seems to be associated with elite endurance performance, while other variants of the ß-adrenergic receptors' genes do not seem to significantly influence top-level sports performance, at least in athletes of Spanish origin.

Association of the intergenic single-nucleotide polymorphism rs10865331 (2p15) with ankylosing spondylitis in a Spanish population.

OBJECTIVE: A recent genome-wide association study has identified 2 single-nucleotide polymorphisms (SNP) associated with ankylosing spondylitis (AS), rs10865331 (2p15) and rs2242944 (21q22). We assessed the association of these SNP with AS in a Spanish population. METHODS: Four hundred fifty-six patients with AS fulfilling the modified New York Criteria and 300 healthy donors were analyzed. Result. SNP rs10865331 (allele A: p = 0.039; genotype: p = 0.016) was significantly associated with AS, while no association was found for rs2242944. CONCLUSION: This is the first study that replicates in an independent cohort the association of the intergenic SNP rs10865331 with susceptibility to AS.

Improved prediction of biochemical recurrence after radical prostatectomy by genetic polymorphisms.

PURPOSE: Single nucleotide polymorphisms are inherited genetic variations that can predispose or protect individuals against clinical events. We hypothesized that single nucleotide polymorphism profiling may improve the prediction of biochemical recurrence after radical prostatectomy. MATERIALS AND METHODS: We performed a retrospective, multi-institutional study of 703 patients treated with radical prostatectomy for clinically localized prostate cancer who had at least 5 years of followup after surgery. All patients were genotyped for 83 prostate cancer related single nucleotide polymorphisms using a low density oligonucleotide microarray. Baseline clinicopathological variables and single nucleotide polymorphisms were analyzed to predict biochemical recurrence within 5 years using stepwise logistic regression. Discrimination was measured by ROC curve AUC, specificity, sensitivity, predictive values, net reclassification improvement and integrated discrimination index. RESULTS: The overall biochemical recurrence rate was 35%. The model with the best fit combined 8 covariates, including the 5 clinicopathological variables prostate specific antigen, Gleason score, pathological stage, lymph node involvement and margin status, and 3 single nucleotide polymorphisms at the KLK2, SULT1A1 and TLR4 genes. Model predictive power was defined by 80% positive predictive value, 74% negative predictive value and an AUC of 0.78. The model based on clinicopathological variables plus single nucleotide polymorphisms showed significant improvement over the model without single nucleotide polymorphisms, as indicated by 23.3% net reclassification improvement (p = 0.003), integrated discrimination index (p <0.001) and likelihood ratio test (p <0.001). Internal validation proved model robustness (bootstrap corrected AUC 0.78, range 0.74 to 0.82). The calibration plot showed close agreement between biochemical recurrence observed and predicted probabilities. CONCLUSIONS: Predicting biochemical recurrence after radical prostatectomy based on clinicopathological data can be significantly improved by including patient genetic information.

Can we identify a power-oriented polygenic profile?

Using the model originally developed by Williams and Folland (J Physiol 586: 113-121, 2008), we determined 1) a "total genotype score" (TGS, from the accumulated combination of the 6 polymorphisms, with a maximum value of "100" for the theoretically optimal polygenic score) in a group of elite power athletes, endurance athletes, and nonathletic controls, and 2) the probability for the occurrence of Spanish individuals with the "perfect" power-oriented profile (i.e., TGS = 100). We analyzed six polymorphism that are candidates to explain individual variations in elite power athletic status or power phenotypes (ACE I/D, ACTN3 R577X, AGT Met235Thr, GDF-8 K153R, IL6 -174 G/C, and NOS3 -786T>C) in 53 elite track and field power athletes (jumpers, sprinters), 100 nonathletic controls, and 100 elite endurance athletes (distance runners and road cyclists) (all Spanish Caucasian males). The mean TGS was significantly higher in power athletes (70.8 +/- 17.3) compared with endurance athletes (60.4 +/- 15.9; P < 0.001) and controls (63.3 +/- 13.2; P = 0.012), whereas it did not differ between the latter two groups (P = 0.366). A total of five power athletes (9.4%, all sprinters) had a theoretically "optimal" TGS of 100 vs. 0 subjects in the other two groups. The probability of a Spanish individual possessing a theoretically optimal polygenic profile for up to the six candidate polymorphisms we studied was very small, i.e., approximately 0.2% (or 1 in 500 Spanish individuals). We have identified a polygenic profile that allows us, at least partly, to distinguish elite power athletes from both endurance athletes and nonathletic population.

The -174 G/C polymorphism of the IL6 gene is associated with elite power performance.

The -174 G/C polymorphism [rs1800795] of the IL6 gene is a candidate to explain individual variations in health and exercise related phenotypes. We compared -174 G/C genotypic and allelic frequencies in three groups of men of the same Caucasian (Spanish) descent: elite endurance athletes (cyclists, runners; n=100); elite power athletes (jumpers, throwers, sprinters; n=53) and non-athletic controls (n=100). The frequency of the GG genotype (P=0.030) and G allele (P=0.026) was higher in the power athletes group compared with the control group. The frequency of the GG genotype (P=0.033) and G allele (P=0.013) was also higher in the power athletes group compared with the endurance athletes group. The odds ratio of being a power athlete if the subject had the GG genotype (dominant model) was 2.471 (95% confidence interval: 1.242-4.915) compared to the control group or the endurance athlete group. We did not find differences between the control and endurance athlete groups. In summary, our findings suggest that the G allele of the IL6 -174 G/C polymorphism might favour sprint/power sports performance.

Are elite endurance athletes genetically predisposed to lower disease risk?

We compared a polygenic profile that combined 33 disease risk-related mutations and polymorphisms among nonathletic healthy control subjects and elite endurance athletes. The study sample comprised 100 healthy Spanish male nonathletic (sedentary) control subjects and 100 male elite endurance athletes. We analyzed 33 disease risk-related mutations and polymorphisms. We computed a health-related total genotype score (TGS, 0-100) from the accumulated combination of the 33 variants. We did not observe significant differences in genotype or allele distributions among groups, except for the rs4994 polymorphism (P < 0.001). The computed health-related TGS was similar among groups (23.8 +/- 1.0 vs. 24.2 +/- 0.8 in control subjects and athletes, respectively; P = 0.553). Similar results were obtained when computing specific TGSs for each main disease category (cardiovascular disease and cancer). We observed no evidence that male elite endurance athletes are genetically predisposed to have lower disease risk than matched nonathletic control subjects.

Prediction of functional impairment and remission in rheumatoid arthritis patients by biochemical variables and genetic polymorphisms.

OBJECTIVE: To develop a model to predict RA outcome based on biochemical variables and single nucleotide polymorphisms (SNPs). METHODS: We collected baseline data from RA patients. SNP genotyping was performed using an oligonucleotide microarray. Remission and severe disability were investigated as outcomes of the study. Logistic regression models and receiver operating characteristic (ROC) curves were used to determine sensitivity (S), specificity (Sp) and likelihood ratio (LR). RESULTS: Six hundred and thirty-two patients (375 in the study and 257 in the validation) were included. Twenty-two out of 152, and 19 out of 208 patients had an HAQ > 2. The model obtained to predict disability included levels of the anti-cyclic citrullinated peptide (anti-CCP) antibodies, ESR and SNP rs2070874 in the IL-4 gene. Homozygous and heterozygous carriers of the IL-4 33T allele had a decreased risk of severe disability. The discriminative power had an area under the curve (AUC) of 0.792 (95% CI 0.694, 0.889), with S 41%, Sp 95% and LR +7.6. Twenty-one out of 268 and 17 out of 211 patients were in remission in the study and validation cohorts, respectively. The model included absence of anti-CCP antibodies and the SNP rs2476601 on the PTPN22 gene. Homozygous and heterozygous carriers of the PTPN22 1858T allele had a decreased probability of remission. The discriminative power had an AUC of 0.842 (95% CI 0.756, 0.928), with S 76%, Sp 86% and LR + 5.4. Predictive ability was confirmed on the validation cohort. CONCLUSIONS: We have developed two models based on laboratory variables that are associated with relevant outcomes for RA patients at disease onset.

The -786 T/C polymorphism of the NOS3 gene is associated with elite performance in power sports.

The NOS3 gene is a candidate to explain individual variations in health and exercise related phenotypes. We compared genotypic and allelic frequencies of the NOS3 -786 T/C polymorphism (rs2070744) in three groups of men of the same Caucasian (Spanish) descent: (i) elite endurance athletes (cyclists, runners; N = 100); (ii) elite power athletes (jumpers, throwers, sprinters; N = 53) and (iii) non-athletic controls (N = 100). The frequency of the TT genotype was significantly higher in power athletes (57%) than in the endurance (33%, P = 0.017) or control group (34%, P = 0.026). The frequency of the T allele was also higher in power sportsmen (71%) than in their endurance (55%, P = 0.003) and control referents (56%, P = 0.015). No differences were observed between control and endurance groups. In summary, the -786 T/C polymorphism of the NOS3 gene seems to be associated with elite performance in power-oriented athletic events (throwing, jumping, sprinting), with the T allele exerting a beneficial effect. The mechanism by which this allele variant might benefit power performance remains to be elucidated.

Association and linkage disequilibrium analyses of APOE polymorphisms in atherosclerosis.

BACKGROUND: Apolipoprotein E (apo E) plays a major role in lipid metabolism, and its genetic variations have been associated with cardiovascular risk. The objective of this study was to investigate the influence of the APOE promoter (-491 A/T, -427 T/C and -219 G/T) and coding region (APOE epsilon2/epsilon3/epsilon4) polymorphisms in atherosclerosis disease by association and linkage disequilibrium analyses. MATERIALS AND METHODS: We analyzed these polymorphisms in a sample of 286 subjects with atherosclerosis disease: 153 subjects with atherothrombotic stroke (ATS) and 133 subjects with ischemic heart disease (IHD); and in two control groups, 103 newborns and 114 elderly subjects. RESULTS: The epsilon4 allele was associated with more severe carotid stenosis in the ATS group, being the percentages of epsilon4 carriers 26.7% and 11.4% for the higher and lower carotid stenosis groups, respectively (p=0,066). The -491 T/T IHD subjects presented higher vessel scores than subjects A/A and A/T genotypes at that position (p=0,041), and the frequencies of -2 (5.1% versus 14.1%, p=0,060) and -427C (10.3% versus 24.4%, p=0,019) alleles were lower in IHD subjects with higher extent score versus lower extent score. The epsilon2 allele was in linkage disequilibrium with the -427C allele in all studied groups, and the -219T allele was associated with the epsilon4 allele in the IHD group. CONCLUSION: In summary, the epsilon2 allele was in linkage disequilibrium with the -427C allele in all studied groups, and only slight associations between the analyzed APOE polymorphisms in the promoter and in the coding region and carotid and coronary vascular disease have been observed.