Confidence intervals for the odds ratio in case-control studies: the state of the art.
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ObjectiveThis study aimed to investigate the potential causal relationships between chronic pain and three key sarcopenia-related quantitative traits: (a) hand grip strength; (b) usual walking pace; and (c) appendicular lean mass, using bidirectional two-sample Mendelian randomization.MethodsWe conducted bidirectional two-sample Mendelian randomization using summary-level data from large-scale genome-wide association studies to assess the genetically predicted associations between chronic pain, including multisite chronic pain and chronic widespread musculoskeletal pain, and the aforementioned sarcopenia-related traits.ResultsMendelian randomization revealed that multisite chronic pain was significantly associated with an increased risk of low hand grip strength (odds ratio = 1.70; p < 0.001) and decreased usual walking pace (odds ratio = 0.81; p < 0.001); chronic widespread musculoskeletal pain was also significantly associated with decreased usual walking pace (odds ratio = 0.15; p < 0.001). Additionally, higher left hand grip strength was significantly associated with a lower risk of multisite chronic pain (odds ratio = 0.90; p< 0.001) and chronic widespread musculoskeletal pain (odds ratio = 0.99; p = 0.002); higher right hand grip strength was significantly associated with a lower risk of multisite chronic pain (odds ratio = 0.91; p = 0.002); and higher usual walking pace was significantly associated with a lower risk of multisite chronic pain (odds ratio = 0.49; p < 0.001) and chronic widespread musculoskeletal pain (odds ratio = 0.92; p < 0.001). No significant causal associations were detected for appendicular lean mass in either direction (all p > 0.05).ConclusionThis study provides genetic evidence supporting potential causal links between chronic pain and key phenotypic components of sarcopenia.
Extreme phenotype sequencing has led to the identification of high-impact rare genetic variants for many complex disorders but has not been applied to studies of severe schizophrenia. We sequenced 112 individuals with severe, extremely treatment-resistant schizophrenia, 218 individuals with typical schizophrenia, and 4,929 controls. We compared the burden of rare, damaging missense and loss-of-function variants between severe, extremely treatment-resistant schizophrenia, typical schizophrenia, and controls across mutation intolerant genes. Individuals with severe, extremely treatment-resistant schizophrenia had a high burden of rare loss-of-function (odds ratio, 1.91; 95% CI, 1.39 to 2.63; P = 7.8 × 10-5) and damaging missense variants in intolerant genes (odds ratio, 2.90; 95% CI, 2.02 to 4.15; P = 3.2 × 10-9). A total of 48.2% of individuals with severe, extremely treatment-resistant schizophrenia carried at least one rare, damaging missense or loss-of-function variant in intolerant genes compared to 29.8% of typical schizophrenia individuals (odds ratio, 2.18; 95% CI, 1.33 to 3.60; P = 1.6 × 10-3) and 25.4% of controls (odds ratio, 2.74; 95% CI, 1.85 to 4.06; P = 2.9 × 10-7). Restricting to genes previously associated with schizophrenia risk strengthened the enrichment with 8.9% of individuals with severe, extremely treatment-resistant schizophrenia carrying a damaging missense or loss-of-function variant compared to 2.3% of typical schizophrenia (odds ratio, 5.48; 95% CI, 1.52 to 19.74; P = 0.02) and 1.6% of controls (odds ratio, 5.82; 95% CI, 3.00 to 11.28; P = 2.6 × 10-8). These results demonstrate the power of extreme phenotype case selection in psychiatric genetics and an approach to augment schizophrenia gene discovery efforts.
Genomic medicine requires a robust evidence base of variant phenotypic impacts, which remains incomplete even in extensively studied genes with monogenic disease associations. Here, we evaluated the broad potential of using population cohort data to identify evidence that can be used in variant assessment. Across 41 genes related to 18 clinically actionable monogenic phenotypes, we calculated variant-level odds ratios of disease enrichment using data from 469,803 UK Biobank participants. We found significant differences in odds ratio values between ClinVar-labeled pathogenic and benign variants in 11 phenotypes, spanning both common and rare disorders. To facilitate clinical translation, we calibrated the strength of evidence provided by variant-level odds ratios to align with American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP) interpretation guidelines (PS4 criterion) and found that odds ratios may reach "moderate," "strong," or "very strong" evidence, varying by phenotype and gene. Overall, we found that 2.6% (N = 12,350) of participants harbor a rare variant of uncertain significance (VUS) with at least moderate evidence of pathogenicity-an indication of potentially unrecognized disease risk. Finally, by incorporating computational and functional data alongside population-based odds ratios, we identified variants that met the criteria for clinical reclassification. Notably, using this approach, we identified that 12.4% of rare VUSs in LDLR seen in participants meet diagnostic criteria to be classified as likely pathogenic, demonstrating its potential to scale the reclassification of VUSs.
BACKGROUND: Current endoscopic retrograde cholangiopancreatography (ERCP) and cholangioscopic-based diagnostic sampling for indeterminant biliary strictures remain suboptimal. Artificial intelligence (AI)-based algorithms by means of computer vision in machine learning have been applied to cholangioscopy in an effort to improve diagnostic yield. The aim of this study was to perform a systematic review and meta-analysis to evaluate the diagnostic performance of AI-based diagnostic performance of AI-associated cholangioscopic diagnosis of indeterminant or malignant biliary strictures. METHODS: Individualized searches were developed in accordance with PRISMA and MOOSE guidelines, and meta-analysis according to Cochrane Diagnostic Test Accuracy working group methodology. A bivariate model was used to compute pooled sensitivity and specificity, likelihood ratio, diagnostic odds ratio, and summary receiver operating characteristics curve (SROC). RESULTS: Five studies (n=675 lesions; a total of 2,685,674 cholangioscopic images) were included. All but one study analyzed a deep learning AI-based system using a convoluted neural network (CNN) with an average image processing speed of 30 to 60 frames per second. The pooled sensitivity and specificity were 95% (95% CI: 85-98) and 88% (95% CI: 76-94), with a diagnostic accuracy (SROC) of 97% (95% CI: 95-98). Sensitivity analysis of CNN studies (4 studies, 538 patients) demonstrated a pooled sensitivity, specificity, and accuracy (SROC) of 95% (95% CI: 82-99), 88% (95% CI: 72-95), and 97% (95% CI: 95-98), respectively. CONCLUSIONS: Artificial intelligence-based machine learning of cholangioscopy images appears to be a promising modality for the diagnosis of indeterminant and malignant biliary strictures.
BACKGROUND: Females are less likely than males to be diagnosed with attention-deficit hyperactivity disorder (ADHD). When diagnosed, females are older than males. AIMS: In this study, we examined the childhood antecedents of later ADHD diagnosis and its impact on adolescent/emerging adult outcomes, with a focus on females. METHOD: In this cohort study, we used data from a Welsh nation-wide electronic cohort of 13 593 individuals (n = 2680 (19.7%) females) diagnosed with ADHD and 578 793 individuals (n = 286 734 (49.5%) females) without ADHD. We compared females with later diagnoses (ages 12-25) to those with earlier, timely diagnoses (ages 5-11) and no diagnosis, in terms of childhood (ages 5-11) antecedents and adolescent/adult (ages 12-25) outcomes. We also tested for sex differences. RESULTS: Although females with earlier ADHD diagnosis showed more health and educational difficulties in childhood than those with later diagnosed ADHD (odds ratios ranged from 0.18 to 0.92), there was clear evidence of these difficulties in females with later diagnosed ADHD, compared with females without ADHD (odds ratios: 1.07-9.02). In adolescence/early adulthood, females with later diagnosed ADHD used more healthcare services and had worse mental health, educational and socioeconomic outcomes than females diagnosed earlier (odds ratios: 1.39-4.96) and those without ADHD (odds ratios: 1.54-23.98). Many of these outcomes were exacerbated in females compared with males. CONCLUSIONS: The results demonstrate that later ADHD diagnosis is associated with significant negative outcomes by adolescence and disproportionately disadvantages females. Despite later diagnosis, there was clear evidence of childhood mental health and educational difficulties when compared with females without ADHD. Therefore, timely childhood ADHD diagnosis may help to mitigate later risks, especially for females.
The etiology of pediatric psychiatric disorders is complex, involving intergenerational influences and a child's own developmental health. We aimed to investigate the potential effects of genetically predicted childhood traits (childhood obesity, absence epilepsy, intelligence) and parental health traits (longevity, Alzheimer disease, severe depression) on the risk of several childhood and adolescent psychiatric disorders. We employed a 2-sample Mendelian randomization (MR) design using summary statistics from large-scale genome-wide association studies. Data for parental health exposures were primarily from the UK Biobank. Data for childhood trait exposures were from various consortia. Data for outcomes - conduct disorder, mixed conduct and emotional disorders, attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and broader behavioral/emotional and social disorders - were sourced from FinnGen and the Psychiatric Genomics Consortium, among others. We used the inverse-variance weighted method for the primary analysis, with MR-Egger, weighted median, and weighted mode as additional analyses. To test the robustness of the results, we conducted sensitivity analyses using MR-Egger regression, Cochran Q test for heterogeneity, the MR-pleiotropy residual sum and outlier test, and a leave-one-out analysis. Genetic liability for childhood obesity was associated with an increased risk of ASD (odds ratio = 1.06, P = .016) and ADHD (odds ratio = 1.09, P = .026), even though these associations did not withstand multiple testing correction. No other robust, statistically significant causal associations were identified. Sensitivity analyses showed limited evidence of bias from horizontal pleiotropy for the main findings. Our findings provide MR evidence supporting potential links from genetic liability for childhood obesity to increased risks of ASD and ADHD. These results highlight the importance of considering a child's early-life health trajectory in the etiology of pediatric psychiatric disorders.
PURPOSE: Genome-wide association studies have identified many common variants associated at low effect sizes with various cancers. Summing the effects of these variants into polygenic risk scores (PRS) can improve cancer risk prediction. However, cross-cancer and cross-phenotype pleiotropic associations of cancer-specific PRS are limited. METHODS: Using logistic regression models, we tested the association of 13 cancer-specific PRS with curated phenotypes representing the same 13 cancers and 340 cancer and cardiometabolic phecodes in 560,287 individuals (114,255 African ancestry [AFR] and 446,032 European ancestry [EUR]) from the Million Veteran Program. Models were stratified by ancestry and used age, principal components, and cancer-specific PRS per standard deviation as independent variables, and correction was applied for multiple comparisons. RESULTS: All 13 cancer-specific PRS were significantly associated with their respective cancers among EUR individuals with odds ratios per standard deviation of PRS (odds ratio [OR]) 1.05-1.70. Among AFR individuals, the effect sizes of the cancer PRS were lower, with OR 1.01-1.48, and cancer-specific PRS were significantly associated with their respective cancers for five of 13 cancers (bladder, breast in female patients, colorectal, prostate, and thyroid). In cancer-cancer pleiotropy studies, only the renal cancer-specific PRS was significantly associated with skin cancer (OR = 1.04, P = 4.5 × 10-06) among EUR individuals. PheWAS demonstrated five positive pleotropic associations with cardiometabolic conditions (thyroid cancer PRS with thyroid goiter, oral cancer PRS with diabetes phenotypes, and hypothyroidism) and two negative associations (oral and lung cancer PRS separately with coronary artery disease). CONCLUSION: Cancer PRS have stronger associations per cancer among EUR versus AFR individuals. In contrast to PRS of other chronic diseases, the majority of cancer-related PRS are highly specific and pleiotropic associations with other cancers and cardiometabolic traits are uncommon.
BACKGROUND: Maintaining normothermia throughout the peri-operative period prevents the occurrence of complications related to hypothermia. OBJECTIVE: To determine the effect of a thermal care bundle with a short prewarming period on inadvertent peri-operative hypothermia (IPH), surgical site infection (SSI), and unplanned readmission among osteosynthesis patients, and to identify associated variables. DESIGN: Open-label, randomised controlled trial. SETTING: University hospital. PATIENTS: One hundred and forty-eight patients who underwent osteosynthesis surgery. INTERVENTION: The intervention group received the thermal care bundle, which consisted in prewarming patients 10 min before anaesthesia delivery and maintaining body temperature with a forced air device during surgery and the immediate postoperative period; in addition, the operating room environmental temperature was kept at 21 °C, and fluids were warmed to 38 °C. MAIN OUTCOME MEASURES: For the primary objective, hypothermia was defined as core body temperature below 36 °C and measured using the 3M Spot On zero heat flux sensor. Core temperature was recorded upon admission to the pre-operative holding area and subsequently every 30 min until postanaesthesia care unit (PACU) discharge. Secondary objectives were SSI and readmissions: a follow-up at 30 to 60 and 90 days was performed by the principal investigator. RESULTS: All 148 patients completed the study, and there were no significant differences between the groups at baseline. At the start of surgery, the incidence of hypothermia was significantly lower in the bundle group (1.3 vs. 9.9% among controls; odds ratio = 7.59, P  = 0.021). A significantly lower incidence of hypothermia was also observed at admission to the PACU (14.3% in the bundle group vs. 29.6% among controls; odds ratio = 2.07; P  = 0.024). Application of the bundle increased patients' core body temperature by 0.13 °C (95% confidence interval (CI), 0.003 to 0.254; P  = 0.045). Patients in the bundle group had a slightly lower observed incidence of wound infections requiring readmission (odds ratio = 0.35; 95% CI, 0.04 to 2.92), although this difference was not statistically significant ( P  = 0.332). CONCLUSIONS: The bundle reduces peri-operative hypothermia by up to 59%, but does not affect on SSI; factors like presurgery hospital stay, operating room and PACU occupancy were identified as risk factors for SSI. REGISTRATION: 21 July 2022: NCT05469958 (Clinical Trials.gov), first recruitment 15 August 2022.
The discharge ECG's of 641 patients with acute myocardial infarction (AMI) (WHO categories "definite" and "possible" AMI) were studied to assess the prognostic value of P wave morphology as an index of left ventricular dysfunction. Of 69 patients with abnormal P terminal force (PTF), i.e., --0.03 mm.sec. or more negative, 53.6 per cent died within the next 5 years of ischemic heart disease, compared with 20.4 per cent of 558 patients with normal PTF. The odds ratio (age-corrected risk to die, Mantel-Haenszel test) was 4.1 (95 per cent confidence limits 2.4 to 7.0). The mortality curve of patients with normal PTF was linear whereas there was an abrupt rise in mortality rate during the first six months if PTF was abnormal. Of a group of 15 patients with the frontal axis of the terminal P wave --30 degrees or more negative, 8 died (Odds ratio 4.7; 1.3 to 17.1). Ten patients had atrial fibrillation, and five of them died (Odds ratio 2.; 0.5 to 12.9). In 14 cases the duration of the P wave in Lead II was 0.12 sec. but it showed no relationship to mortality (p less than 0.10). The significance of the P wave morphology on the discharge ECG to long-term survival after MI has been demonstrated. These simple ECG variables, related to left ventricular failure, can easily be put to clinical use to differentiate MI patients who are in greater risk of dying during the chronic phase.
Previous studies have revealed a potential association between psoriasis and coronary artery disease (CAD). However, the causal relationship between the 2 remains unclear. This study aims to assess the causal link between psoriasis and CAD, which encompasses coronary heart disease, myocardial infarction, and angina pectoris. After obtaining genome-wide association studies data on psoriasis and CAD, we selected appropriate single nucleotide polymorphisms for Mendelian randomization (MR) analysis. The inverse-variance weighted method was used as the main analytical method. The inverse-variance weighted method indicated that psoriasis was associated with a higher risk of CAD (odds ratio = 11.538, 95% confidence interval = 4.498-29.595, P < .001), and coronary heart disease (odds ratio = 1.080, 95% confidence interval = 1.031-1.132, P = .001). Reverse MR analyses did not show causal effects of CAD on psoriasis. This study shows a significant causal association between psoriasis and incidence of CAD. However, there is no reverse causal association between CAD and psoriasis.
BACKGROUND: The relationship between plasma lipoprotein(a) [Lp(a)] levels and metabolic dysfunction-associated steatotic liver disease (MASLD) remains unclear. The aim of this study was to examine the combined effects of Lp(a) levels on liver and vascular damage. METHODS: The study was conducted using the Liver-Bible cohort of individuals with metabolic dysfunction (n = 859, 808 with genomic information) and the Milan Biobank (n = 6963). Genome-wide association studies (GWAS) and polygenic risk scores (PRS) were used to evaluate the inherited factors influencing plasma Lp(a) levels. RESULTS: In the Liver-Bible cohort, genetic variation in the LPA gene was the strongest determinant of Lp(a), followed by liver stiffness measurement (LSM). Additionally, circulating Lp(a) levels, but not genetic predisposition, were inversely related to LSM, suggesting that MASLD severity may affect Lp(a) secretion. Among participants with more severe insulin resistance (n = 250), Lp(a) levels (odds ratio 6.7, 95% CI 1.0-53.0, p = 0.046) and LSM (odds ratio 13.7, 95% CI 1.4-172.2, p = 0.023) were associated with greater prevalence of carotid atherosclerotic plaques, regardless of traditional cardiovascular risk factors. In the Milan Biobank, genetically predicted higher Lp(a) levels tended to increase the risk of liver-related outcomes, whereas genetically predicted MASLD was associated with lower circulating Lp(a) levels. CONCLUSIONS: The results of this study suggest that liver damage is more likely the cause of reduced plasma Lp(a) levels rather than a consequence. Assessing plasma Lp(a) levels and the extent of liver damage could improve the prediction of vascular damage.
Let P1 be the probability of a disease in one population and P2 be the probability of a disease in a second population. The ratio of these quantities, R = P1/P2, is termed the relative risk. We consider first the analyses of the relative risk from retrospective studies. The relation between the relative risk and the odds ratio (or cross-product ratio) is developed. The odds ratio can be considered a parameter of an exponential model possessing sufficient statistics. This permits the development of exact significance tests and confidence intervals in the conditional space. Unconditional tests and intervals are also considered briefly. The consequences of misclassification errors and ignoring matching or stratifying are also considered. The various methods are extended to combination of results over the strata. Examples of case-control studies testing the association between HL-A frequencies and cancer illustrate the techniques. The parallel analyses of prospective studies are given. If P1 and P2 are small with large samples sizes the appropriate model is a Poisson distribution. This yields a exponential model with sufficient statistics. Exact conditional tests and confidence intervals can then be developed. Here we consider the case where two populations are compared adjusting for sex differences as well as for the strata (or covariate) differences such as age. The methods are applied to two examples: (1) testing in the two sexes the ratio of relative risks of skin cancer in people living in different latitudes, and (2) testing over time the ratio of the relative risks of cancer in two cities, one of which fluoridated its drinking water and one which did not.
BACKGROUND: Genome-wide association studies (GWAS) and subsequent functional interpretation have been used to identify susceptible genes and potential drug-repositioning candidates. This study aimed to identify genes associated with colorectal cancer (CRC) and potential drug-repositioning candidates. METHODS: Patients with CRC at Seoul National University Hospital (SNUH, discovery study) and Chonnam National University Hospital (CNUH, replication study) were included as case groups. The Korean Genome and Epidemiology Study (KoGES) participants were included as a control group. Single-nucleotide polymorphisms (SNPs) were extracted from blood-derived DNA (N = 409,063). A SNP-based logistic regression model was applied. Furthermore, post-GWAS analysis was conducted. Drug-repositioning candidates were identified using a pre-trained deep neural network and the druggability assessment tool. RESULTS: In the discovery study, we conducted a 1:3 age- and sex-matched case-control study that included 500 CRC cases (mean age 63.0 ± 7.15 years) and 1,500 healthy controls (mean age 62.9 ± 7.07 years), each group comprising 50% males and 50% females. The replication study enrolled 4,860 patients with CRC and 46,384 healthy controls. The two-stage GWAS revealed statistically significant associations among MKLN1 (rs75170436, 7q32.3, beta (log odds ratio) = - 0.90, Pmeta = 5.90 × 10-13), MMP14 (rs3751489, 14q11.2, beta (log odds ratio) = - 1.91, Pmeta = 2.31 × 10-12). Post-GWAS functional analysis revealed strong associations on two genes highlighting deleterious effects and increased gene expression. Drug-repositioning analysis identified GW0742 (PPARβ/δ agonist) with the highest binding score and druggability score for MMP14 with a reference allele (12.06, 0.85). CONCLUSIONS: Using GWAS, MKLN1 and MMP14 were found to be associated with CRC development and we identified GW0742 (PPARβ/δ agonist) as a potential drug-repositioning candidate for CRC based on MKLN1 and MMP14. These findings improve the understanding of CRC development and provide insights into novel therapeutic targets and candidates for CRC treatment.
BACKGROUND: Pulmonary cryptococcosis(PC) presents diagnostic challenges because of its non-specific clinical and radiological manifestations. Bronchoalveolar lavage fluid (BALF)-based testing, which includes latex agglutination (LA) and lateral flow assay (LFA), offers a minimally invasive diagnostic method, yet its pooled diagnostic accuracy remains unclear. METHODS: We systematically searched PubMed, Embase, Cochrane Library, and Scopus from inception to May 2026. Studies evaluating BALF-based testing for PC with extractable 2 × 2 data were included. The methodological quality of relevant studies was assessed by the QUADAS-2 tool. Pooled sensitivity, specificity, likelihood ratios, and diagnostic odds ratio (DOR) were estimated using a bivariate random-effects model. Subgroup analyses were performed by testing method and reference standard type. Heterogeneity was evaluated through paired forest plots, HSROC visualization, and exploratory bivariate meta-regression. RESULTS: The pooled sensitivity was 0.87 (95% CI: 0.81-0.91), and the specificity was 0.99 (95% CI: 0.982 - 0.995). The pooled positive likelihood ratio (PLR) was 88.00 (95% CI: 47.39 - 163.42), the negative likelihood ratio (NLR) was 0.13 (95% CI: 0.09 -0.20), and the DOR was 658.50 (95% CI: 285.36-1519.55). No significant threshold effect or publication bias was detected. Exploratory meta-regression suggested a possible assay-method effect in the joint model (P = 0.03), mainly driven by specificity (P = 0.01). CONCLUSIONS: The study demonstrates the high accuracy of CrAg in BALF for the diagnosis of pulmonary cryptococcosis, supporting its role as an important adjunctive diagnostic tool, particularly when tissue biopsy is not feasible or rapid results are needed. Larger prospective studies with standardized protocols are needed to validate these estimates.
Background: Acute kidney injury (AKI) is associated with high mortality and adverse outcomes. Fibroblast growth factor 23 (FGF23) has emerged as a potential biomarker for AKI; however, its diagnostic and prognostic utility remains inconsistent.Methods: We conducted a systematic review and meta-analysis of studies evaluating circulating intact FGF23 (iFGF23) or C-terminal FGF23 (cFGF23) (PROSPERO: CRD42022302659). PubMed, EMBASE, CNKI, and Wanfang databases were searched through June 9, 2026. QUADAS-2 was used for quality assessment. A random-effects bivariate model pooled sensitivity, specificity, positive/negative likelihood ratio (PLR/NLR), diagnostic odds ratio (DOR), and area under the summary receiver operating characteristic curve (SROC AUC).Results: Twenty-three studies were included: 17 diagnostic, 6 prognostic (one addressing both). For AKI diagnosis, the pooled sensitivity was 0.79 (95% CI 0.73-0.86), specificity 0.82 (95% CI 0.75-0.89), PLR 4.40 (95% CI 2.59-6.21), NLR 0.25 (95% CI 0.16-0.34), DOR 17.49 (95% CI 8.67-35.16), and SROC AUC 0.87 (95% CI 0.81-0.92). Substantial heterogeneity was observed (I2 = 67%), with iFGF23 demonstrating higher accuracy than cFGF23 (AUC 0.91 vs 0.81). For AKI mortality, pooled sensitivity was 0.77 (95% CI 0.69-0.84), specificity 0.76 (95% CI 0.70-0.82), DOR 10.89 (95% CI 6.86-17.30), and SROC AUC 0.77 (95% CI 0.70-0.83). Significant heterogeneity was noted (I2 = 86.2% for sensitivity, 80.4% for specificity). No significant publication bias was detected.Conclusions: Circulating FGF23 exhibits moderate-to-high diagnostic and moderate prognostic performance in AKI, though interpretation is limited by substantial heterogeneity. It may serve as a complementary biomarker for risk stratification, pending further validation with standardized protocols.
OBJECTIVES: The MUC5B promoter single nucleotide polymorphism (SNP) rs35705950 has been associated with idiopathic pulmonary fibrosis (IPF) and RA-related interstitial lung disease (ILD), but not with SSc-ILD. We hypothesized that the MUC5B promoter polymorphism or other IPF susceptibility loci are associated with an increased risk for the uncommon SSc-usual interstitial pneumonia (UIP) endophenotype, rather than SSc-ILD in general. METHODS: We performed a cross-sectional study of SSc-ILD patients from four US Scleroderma Programs to investigate the frequency of MUC5B rs35705950 and 12 additional IPF susceptibility loci. SSc-ILD patients were stratified by high resolution chest CT (HRCT) imaging findings into UIP and non-UIP groups. Analysis of HRCTs performed by a thoracic radiologist blinded to participants' characteristics classified each scan as definite UIP, probable UIP, indeterminate or alternative diagnosis, according to American Thoracic Society criteria. RESULTS: Four-hundred and eighty-nine SSc-ILD patients were included; 80% were female and 75% were White. Twenty-three (4.7%) patients had a definite UIP pattern. The MUC5B SNP rs35705950 was not associated with a definite UIP pattern in SSc-ILD. In contrast, patients carrying two copies of the IPF risk gene FAM13A minor allele rs2609255 had significantly higher odds of a definite UIP pattern compared with the other patterns (odds ratio 3.40, 95% CI 1.19-9.70), and compared with an alternative diagnosis (odds ratio 3.65, 95% CI 1.25-10.65). CONCLUSION: We demonstrated a novel association between FAM13A and SSc-UIP. Contrary to IPF and RA-ILD, the MUC5B promoter polymorphism was not associated with a definite UIP pattern in SSc-ILD.