Genome-wide association study identifies the GLDC/IL33 locus associated with survival of osteosarcoma patients

Survival rates for osteosarcoma, the most common primary bone cancer, have changed little over the past three decades and are particularly low for patients with metastatic disease. We conducted a multi‐institutional genome‐wide association study (GWAS) to identify germline genetic variants associated with overall survival in 632 patients with osteosarcoma, including 523 patients of European ancestry and 109 from Brazil. We conducted a time‐to‐event analysis and estimated hazard ratios (HR) and 95% confidence intervals (CI) using Cox proportional hazards models, with and without adjustment for metastatic disease. The results were combined across the European and Brazilian case sets using a random‐effects meta‐analysis. The strongest association after meta‐analysis was for rs3765555 at 9p24.1, which was inversely associated with overall survival (HR = 1.76; 95% CI 1.41–2.18, p = 4.84 × 10−7). After imputation across this region, the combined analysis identified two SNPs that reached genome‐wide significance. The strongest single association was with rs55933544 (HR = 1.9; 95% CI 1.5–2.4; p = 1.3 × 10−8), which localizes to the GLDC gene, adjacent to the IL33 gene and was consistent across both the European and Brazilian case sets. Using publicly available data, the risk allele was associated with lower expression of IL33 and low expression of IL33 was associated with poor survival in an independent set of patients with osteosarcoma. In conclusion, we have identified the GLDC/IL33 locus on chromosome 9p24.1 as associated with overall survival in patients with osteosarcoma. Further studies are needed to confirm this association and shed light on the biological underpinnings of this susceptibility locus

X chromosome inactivation does not necessarily determine the severity of the phenotype in Rett syndrome patients

Rett syndrome (RTT) is a severe neurological disorder usually caused by mutations in the MECP2 gene. Since the MECP2 gene is located on the X chromosome, X chromosome inactivation (XCI) could play a role in the wide range of phenotypic variation of RTT patients; however, classical methylation-based protocols to evaluate XCI could not determine whether the preferentially inactivated X chromosome carried the mutant or the wild-type allele. Therefore, we developed an allele-specific methylation-based assay to evaluate methylation at the loci of several recurrent MECP2 mutations. We analyzed the XCI patterns in the blood of 174 RTT patients, but we did not find a clear correlation between XCI and the clinical presentation. We also compared XCI in blood and brain cortex samples of two patients and found differences between XCI patterns in these tissues. However, RTT mainly being a neurological disease complicates the establishment of a correlation between the XCI in blood and the clinical presentation of the patients. Furthermore, we analyzed MECP2 transcript levels and found differences from the expected levels according to XCI. Many factors other than XCI could affect the RTT phenotype, which in combination could influence the clinical presentation of RTT patients to a greater extent than slight variations in the XCI pattern

Identification and Analysis of Natural Building Blocks for Evolution-Guided Fragment-Based Protein Design

Natural evolution has generated an impressively diverse protein universe via duplication and recombination from a set of protein fragments that served as building blocks. The application of these concepts to the design of new proteins using subdomain-sized fragments from different folds has proven to be experimentally successful. To better understand how evolution has shaped our protein universe, we performed an all-against-all comparison of protein domains representing all naturally existing folds and identified conserved homologous protein fragments. Overall, we found more than 1000 protein fragments of various lengths among different folds through similarity network analysis. These fragments are present in very different protein environments and represent versatile building blocks for protein design. These data are available in our web server called F(old P)uzzle (fuzzle.uni-bayreuth.de), which allows to individually filter the dataset and create customized networks for folds of interest. We believe that our results serve as an invaluable resource for structural and evolutionary biologists and as raw material for the design of custom-made proteins

Genome-wide association study identifies the GLDC/IL33 locus associated with survival of osteosarcoma patients

Survival rates for osteosarcoma, the most common primary bone cancer, have changed little over the past three decades and are particularly low for patients with metastatic disease. We conducted a multi-institutional genome-wide association study (GWAS) to identify germline genetic variants associated with overall survival in 632 patients with osteosarcoma, including 523 patients of European ancestry and 109 from Brazil. We conducted a time-to-event analysis and estimated hazard ratios (HR) and 95% confidence intervals (CI) using Cox proportional hazards models, with and without adjustment for metastatic disease. The results were combined across the European and Brazilian case sets using a random-effects meta-analysis. The strongest association after meta-analysis was for rs3765555 at 9p24.1, which was inversely associated with overall survival (HR=1.76; 95% CI 1.41-2.18, p=4.84 x 10(-7)). After imputation across this region, the combined analysis identified two SNPs that reached genome-wide significance. The strongest single association was with rs55933544 (HR=1.9; 95% CI 1.5-2.4; p=1.3 x 10(-8)), which localizes to the GLDC gene, adjacent to the IL33 gene and was consistent across both the European and Brazilian case sets. Using publicly available data, the risk allele was associated with lower expression of IL33 and low expression of IL33 was associated with poor survival in an independent set of patients with osteosarcoma. In conclusion, we have identified the GLDC/IL33 locus on chromosome 9p24.1 as associated with overall survival in patients with osteosarcoma. Further studies are needed to confirm this association and shed light on the biological underpinnings of this susceptibility locus. What's new? To date, prognostic factors associated with survival in patients with osteosarcoma are scarce. Here, the authors conducted a multi-institutional genome-wide association study to explore whether germline genetics may contribute to overall survival in osteosarcoma patients. They identified a common single nucleotide polymorphism, rs55933544, located in the GLDC gene on chromosome 9, associated with poor survival. The rs55933544 risk allele was associated with lower expression of the nearby gene, IL33. These findings, if replicated in additional populations, form the foundation for future studies of the molecular basis of the association of the GLDC/IL33 (rs55933544) variant with survival in osteosarcoma.Intramural Research Program of the Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of HealthBone Cancer Research Trust UKChair's Grant of the Children's Oncology Group from the National Cancer Institute, National Institutes of HealthHuman Specimen Banking of the Children's Oncology Group from the National Cancer Institute, National Institutes of HealthWWWW (QuadW) Foundation, Inc.Ontario Research FundCanadian Foundation for InnovationRegione Emilia-RomagnaRoyal National Orthopaedic Hospital Musculoskeletal Research Programme and BiobankNational Institute for Health Research UCLH Biomedical Research CentreUCL Experimental Cancer CentreFIS, ISCIII and La Fundacion Bancaria "La Caixa"Fundacion Caja NavarraAECC ProjectRainbows for Kate FoundationLiddy Shriver Sarcoma InitiativeVictorian Cancer AgencyAustralian National Health and Medical Research CouncilCancer AustraliaNCI, Div Canc Epidemiol & Genet, NIH, 9609 Med Ctr Dr,Room 6E524, Bethesda, MD 20850 USAInformat Management Serv IMS Inc, Rockville, MD USAOhio State Univ, Nationwide Childrens Hosp, Dept Pathol & Pediat, Columbus, OH 43210 USAUniv Fed Sao Paulo, GRAACC, Pediat Oncol Inst, Lab Genet, Sao Paulo, BrazilUniv Texas MD Anderson Canc Ctr, Dept Pediat, Houston, TX 77030 USAUCL Canc Inst, Huntley St, London, England|Royal Natl Orthopaed Hosp NHS Trust, Stanmore, Middx, EnglandUniv Toronto, Mt Sinai Hosp, Samuel Lunenfeld Res Inst, Litwin Ctr Canc Genet, Toronto, ON, CanadaUniv Navarra, Univ Clin Navarra, Dept Pediat, Pamplona, SpainOrthopaed Rizzoli Inst, Lab Expt Oncol, Bologna, ItalyUniv Southern Calif, Keck Sch Med, Los Angeles, CA USAGarvan Inst Med Res, Kinghorn Canc Ctr, Darlinghurst, NSW, AustraliaUniv Minnesota, Dept Pediat, Minneapolis, MN 55455 USAFrederick Natl Lab Canc Res, Leidos Biomed Res, Canc Genom Res Lab, Frederick, MD USAUniv Fed Sao Paulo, GRAACC, Pediat Oncol Inst, Lab Genet, Sao Paulo, BrazilNIH: U10 CA98543NIH: U24 CA114766]UCL-ECC: PI13/01476ANHMRC: APP1004017Cancer Australia: APP1067094Web of Scienc

Frequency of Pathogenic Germline Variants in Cancer-Susceptibility Genes in Patients With Osteosarcoma

IMPORTANCE: Osteosarcoma, the most common malignant bone tumor in children and adolescents, occurs in a high number of cancer predisposition syndromes that are defined by highly penetrant germline mutations. The germline genetic susceptibility to osteosarcoma outside of familial cancer syndromes remains unclear. OBJECTIVE: To investigate the germline genetic architecture of 1244 patients with osteosarcoma. DESIGN, SETTING, AND PARTICIPANTS: Whole-exome sequencing (n = 1104) or targeted sequencing (n = 140) of the DNA of 1244 patients with osteosarcoma from 10 participating international centers or studies was conducted from April 21, 2014, to September 1, 2017. The results were compared with the DNA of 1062 individuals without cancer assembled internally from 4 participating studies who underwent comparable whole-exome sequencing and 27 173 individuals of non-Finnish European ancestry who were identified through the Exome Aggregation Consortium (ExAC) database. In the analysis, 238 high-interest cancer-susceptibility genes were assessed followed by testing of the mutational burden across 736 additional candidate genes. Principal component analyses were used to identify 732 European patients with osteosarcoma and 994 European individuals without cancer, with outliers removed for patient-control group comparisons. Patients were subsequently compared with individuals in the ExAC group. All data were analyzed from June 1, 2017, to July 1, 2019. MAIN OUTCOMES AND MEASURES: The frequency of rare pathogenic or likely pathogenic genetic variants. RESULTS: Among 1244 patients with osteosarcoma (mean [SD] age at diagnosis, 16 [8.9] years [range, 2-80 years]; 684 patients [55.0%] were male), an analysis restricted to individuals with European ancestry indicated a significantly higher pathogenic or likely pathogenic variant burden in 238 high-interest cancer-susceptibility genes among patients with osteosarcoma compared with the control group (732 vs 994, respectively; P = 1.3 × 10−18). A pathogenic or likely pathogenic cancer-susceptibility gene variant was identified in 281 of 1004 patients with osteosarcoma (28.0%), of which nearly three-quarters had a variant that mapped to an autosomal-dominant gene or a known osteosarcoma-associated cancer predisposition syndrome gene. The frequency of a pathogenic or likely pathogenic cancer-susceptibility gene variant was 128 of 1062 individuals (12.1%) in the control group and 2527 of 27 173 individuals (9.3%) in the ExAC group. A higher than expected frequency of pathogenic or likely pathogenic variants was observed in genes not previously linked to osteosarcoma (eg, CDKN2A, MEN1, VHL, POT1, APC, MSH2, and ATRX) and in the Li-Fraumeni syndrome-associated gene, TP53. CONCLUSIONS AND RELEVANCE: In this study, approximately one-fourth of patients with osteosarcoma unselected for family history had a highly penetrant germline mutation requiring additional follow-up analysis and possible genetic counseling with cascade testing

Genome-wide association study identifies two susceptibility loci for osteosarcoma

Osteosarcoma is the most common primary bone malignancy of adolescents and young adults. To better understand the genetic etiology of osteosarcoma, we performed a multistage genome-wide association study consisting of 941 individuals with osteosarcoma (cases) and 3,291 cancer-free adult controls of European ancestry. Two loci achieved genome-wide significance: a locus in the GRM4 gene at 6p21.3 (encoding glutamate receptor metabotropic 4; rs1906953; P = 8.1 × 10⁻⁹) and a locus in the gene desert at 2p25.2 (rs7591996 and rs10208273; P = 1.0 × 10⁻⁸ and 2.9 × 10⁻⁷, respectively). These two loci warrant further exploration to uncover the biological mechanisms underlying susceptibility to osteosarcoma

Genome-wide association study identifies two susceptibility loci for osteosarcoma

Osteosarcoma is the most common primary bone malignancy of adolescents and young adults. To better understand the genetic etiology of osteosarcoma, we performed a multistage genome-wide association study consisting of 941 individuals with osteosarcoma (cases) and 3,291 cancer-free adult controls of European ancestry. Two loci achieved genome-wide significance: a locus in the GRM4 gene at 6p21.3 (encoding glutamate receptor metabotropic 4; rs1906953; P = 8.1 x 10(-9)) and a locus in the gene desert at 2p25.2 (rs7591996 and rs10208273; P = 1.0 x 10(-8) and 2.9 x 10(-7), respectively). These two loci warrant further exploration to uncover the biological mechanisms underlying susceptibility to osteosarcoma