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Subasri V, Light N, Kanwar N, Brzezinski J, Luo P, Hansford JR, Cairney E, Portwine C, Elser C, Finlay JL, Nichols KE, Alon N, Brunga L, Anson J, Kohlmann W, de Andrade KC, Khincha PP, Savage SA, Schiffman JD, Weksberg R, Pugh TJ, Villani A, Shlien A, Goldenberg A, Malkin D. Multiple Germline Events Contribute to Cancer Development in Patients with Li-Fraumeni Syndrome. CANCER RESEARCH COMMUNICATIONS 2023; 3:738-754. [PMID: 37377903 PMCID: PMC10150777 DOI: 10.1158/2767-9764.crc-22-0402] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 01/19/2023] [Accepted: 03/29/2023] [Indexed: 06/29/2023]
Abstract
Li-Fraumeni syndrome (LFS) is an autosomal dominant cancer-predisposition disorder. Approximately 70% of individuals who fit the clinical definition of LFS harbor a pathogenic germline variant in the TP53 tumor suppressor gene. However, the remaining 30% of patients lack a TP53 variant and even among variant TP53 carriers, approximately 20% remain cancer-free. Understanding the variable cancer penetrance and phenotypic variability in LFS is critical to developing rational approaches to accurate, early tumor detection and risk-reduction strategies. We leveraged family-based whole-genome sequencing and DNA methylation to evaluate the germline genomes of a large, multi-institutional cohort of patients with LFS (n = 396) with variant (n = 374) or wildtype TP53 (n = 22). We identified alternative cancer-associated genetic aberrations in 8/14 wildtype TP53 carriers who developed cancer. Among variant TP53 carriers, 19/49 who developed cancer harbored a pathogenic variant in another cancer gene. Modifier variants in the WNT signaling pathway were associated with decreased cancer incidence. Furthermore, we leveraged the noncoding genome and methylome to identify inherited epimutations in genes including ASXL1, ETV6, and LEF1 that confer increased cancer risk. Using these epimutations, we built a machine learning model that can predict cancer risk in patients with LFS with an area under the receiver operator characteristic curve (AUROC) of 0.725 (0.633-0.810). Significance Our study clarifies the genomic basis for the phenotypic variability in LFS and highlights the immense benefits of expanding genetic and epigenetic testing of patients with LFS beyond TP53. More broadly, it necessitates the dissociation of hereditary cancer syndromes as single gene disorders and emphasizes the importance of understanding these diseases in a holistic manner as opposed to through the lens of a single gene.
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Affiliation(s)
- Vallijah Subasri
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
- Vector Institute, Toronto, Ontario, Canada
| | - Nicholas Light
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Nisha Kanwar
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jack Brzezinski
- Division of Haematology/Oncology, The Hospital for Sick Children, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Ping Luo
- Princess Margaret Cancer Center, University Health Network, Toronto, Ontario, Canada
| | - Jordan R. Hansford
- Children's Cancer Centre, Royal Children's Hospital, Melbourne, Victoria, Australia
- Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Pediatrics, University of Melbourne, Melbourne, Australia
- Michael Rice Cancer Centre, Women's and Children's Hospital, North Adelaide, South Australia, Australia
- South Australia Health and Medical Research Institute, Adelaide, South Australia, Australia
- South Australia Immunogenomics Cancer Institute, University of Adelaide, Adelaide, Australia
| | - Elizabeth Cairney
- Department of Paediatrics, London Health Sciences Centre and Western University, London, Ontario, Canada
| | - Carol Portwine
- Department of Paediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Christine Elser
- Department of Medical Oncology, Princess Margaret Hospital and Mount Sinai Hospital, Toronto, Ontario, Canada
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Jonathan L. Finlay
- Neuro-Oncology Program, Nationwide Children's Hospital and The Ohio State University, Columbus, Ohio
| | - Kim E. Nichols
- Department of Oncology, St Jude Children's Research Hospital, Memphis, Tennessee
| | - Noa Alon
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ledia Brunga
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jo Anson
- Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah
| | - Wendy Kohlmann
- Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah
| | - Kelvin C. de Andrade
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, NCI, Bethesda, Maryland
| | - Payal P. Khincha
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, NCI, Bethesda, Maryland
| | - Sharon A. Savage
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, NCI, Bethesda, Maryland
| | - Joshua D. Schiffman
- Department of Pediatrics, University of Utah, Salt Lake City, Utah
- PEEL Therapeutics, Inc., Salt Lake City, Utah
| | - Rosanna Weksberg
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Trevor J. Pugh
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Princess Margaret Cancer Center, University Health Network, Toronto, Ontario, Canada
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
| | - Anita Villani
- Division of Haematology/Oncology, The Hospital for Sick Children, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Adam Shlien
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Anna Goldenberg
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
- Vector Institute, Toronto, Ontario, Canada
- CIFAR: Child and Brain Development, Toronto, Ontario, Canada
- Department of Computer Science, University of Toronto, Toronto, Ontario, Canada
| | - David Malkin
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Haematology/Oncology, The Hospital for Sick Children, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
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Barfield R, Huyghe JR, Lemire M, Dong X, Su YR, Brezina S, Buchanan DD, Figueiredo JC, Gallinger S, Giannakis M, Gsur A, Gunter MJ, Hampel H, Harrison TA, Hopper JL, Hudson TJ, Li CI, Moreno V, Newcomb PA, Pai RK, Pharoah PDP, Phipps AI, Qu C, Steinfelder RS, Sun W, Win AK, Zaidi SH, Campbell PT, Peters U, Hsu L. Genetic Regulation of DNA Methylation Yields Novel Discoveries in GWAS of Colorectal Cancer. Cancer Epidemiol Biomarkers Prev 2022; 31:1068-1076. [PMID: 35247911 PMCID: PMC9081265 DOI: 10.1158/1055-9965.epi-21-0724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 10/05/2021] [Accepted: 02/23/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Colorectal cancer has a strong epigenetic component that is accompanied by frequent DNA methylation (DNAm) alterations in addition to heritable genetic risk. It is of interest to understand the interrelationship of germline genetics, DNAm, and colorectal cancer risk. METHODS We performed a genome-wide methylation quantitative trait locus (meQTL) analysis in 1,355 people, assessing the pairwise associations between genetic variants and lymphocytes methylation data. In addition, we used penalized regression with cis-genetic variants ± 1 Mb of methylation to identify genome-wide heritable DNAm. We evaluated the association of genetically predicted methylation with colorectal cancer risk based on genome-wide association studies (GWAS) of over 125,000 cases and controls using the multivariate sMiST as well as univariately via examination of marginal association with colorectal cancer risk. RESULTS Of the 142 known colorectal cancer GWAS loci, 47 were identified as meQTLs. We identified four novel colorectal cancer-associated loci (NID2, ATXN10, KLHDC10, and CEP41) that reside over 1 Mb outside of known colorectal cancer loci and 10 secondary signals within 1 Mb of known loci. CONCLUSIONS Leveraging information of DNAm regulation into genetic association of colorectal cancer risk reveals novel pathways in colorectal cancer tumorigenesis. Our summary statistics-based framework sMiST provides a powerful approach by combining information from the effect through methylation and residual direct effects of the meQTLs on disease risk. Further validation and functional follow-up of these novel pathways are needed. IMPACT Using genotype, DNAm, and GWAS, we identified four new colorectal cancer risk loci. We studied the landscape of genetic regulation of DNAm via single-SNP and multi-SNP meQTL analyses.
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Affiliation(s)
- Richard Barfield
- Department of Biostatistics and Bioinformatics, Duke University, Durham NC USA
| | - Jeroen R Huyghe
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Mathieu Lemire
- Neurosciences & Mental Health Program, Hospital for Sick Children, Toronto, ON, Canada
| | - Xinyuan Dong
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
- Department of Biostatistics, University of Washington, Seattle, Washington, USA
| | - Yu-Ru Su
- Biostatistics Unit, Kaiser Permanente Washington Health Research Institute, Seattle, Washington
| | - Stefanie Brezina
- Institute of Cancer Research, Department of Medicine I, Medical University Vienna, Vienna, Austria
| | - Daniel D Buchanan
- Colorectal Oncogenomics Group, Department of Clinical Pathology, The University of Melbourne, Parkville, Victoria 3010 Australia
- University of Melbourne Centre for Cancer Research, Victorian Comprehensive Cancer Centre, Parkville, Victoria 3010 Australia
- Genomic Medicine and Family Cancer Clinic, The Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Jane C Figueiredo
- Department of Medicine, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Steven Gallinger
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Marios Giannakis
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts, USA
- The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Andrea Gsur
- Institute of Cancer Research, Department of Medicine I, Medical University Vienna, Vienna, Austria
| | - Marc J Gunter
- International Agency for Research on Cancer (IARC/WHO), Nutrition and Metabolism Branch, Lyon, France
| | - Heather Hampel
- Division of Human Genetics, Department of Internal Medicine, The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA
| | - Tabitha A Harrison
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - John L Hopper
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Epidemiology, School of Public Health and Institute of Health and Environment, Seoul National University, Seoul, South Korea
| | - Thomas J Hudson
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
| | - Christopher I Li
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Victor Moreno
- Oncology Data Analytics Program, Catalan Institute of Oncology-IDIBELL, L’Hospitalet de Llobregat, Barcelona, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
- Department of Clinical Sciences, Faculty of Medicine, University of Barcelona, Barcelona, Spain
- ONCOBEL Program, Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet de Llobregat, Barcelona, Spain
| | - Polly A Newcomb
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
- School of Public Health, University of Washington, Seattle, Washington, USA
| | - Rish K Pai
- Department of Laboratory Medicine and Pathology, Mayo Clinic Arizona, Scottsdale, Arizona, USA
| | - Paul D P Pharoah
- Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
| | - Amanda I Phipps
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
- Department of Epidemiology, University of Washington, Seattle, Washington, USA
| | - Conghui Qu
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Robert S Steinfelder
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Wei Sun
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
- Department of Biostatistics, University of Washington, Seattle, Washington, USA
- Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Aung Ko Win
- Department of Epidemiology, School of Public Health and Institute of Health and Environment, Seoul National University, Seoul, South Korea
| | - Syed H Zaidi
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
| | - Peter T Campbell
- Department of Population Science, American Cancer Society, Atlanta, Georgia, USA
| | - Ulrike Peters
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
- Department of Epidemiology, University of Washington, Seattle, Washington, USA
| | - Li Hsu
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
- Department of Biostatistics, University of Washington, Seattle, Washington, USA
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Petukhova L, Patel AV, Rigo RK, Bian L, Verbitsky M, Sanna-Cherchi S, Erjavec SO, Abdelaziz AR, Cerise JE, Jabbari A, Christiano AM. Integrative analysis of rare copy number variants and gene expression data in alopecia areata implicates an aetiological role for autophagy. Exp Dermatol 2019; 29:243-253. [PMID: 31169925 DOI: 10.1111/exd.13986] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 04/23/2019] [Accepted: 05/09/2019] [Indexed: 12/26/2022]
Abstract
Alopecia areata (AA) is a highly prevalent autoimmune disease that attacks the hair follicle and leads to hair loss that can range from small patches to complete loss of scalp and body hair. Our previous linkage and genome-wide association studies (GWAS) generated strong evidence for aetiological contributions from inherited genetic variants at different population frequencies, including both rare mutations and common polymorphisms. Additionally, we conducted gene expression (GE) studies on scalp biopsies of 96 patients and controls to establish signatures of active disease. In this study, we performed an integrative analysis on these two datasets to test the hypothesis that rare CNVs in patients with AA could be leveraged to identify drivers of disease in our AA GE signatures. We analysed copy number variants (CNVs) in a case-control cohort of 673 patients with AA and 16 311 controls independent of the case-control cohort of 96 research participants used in our GE study. Using an integrative computational analysis, we identified 14 genes whose expression levels were altered by CNVs in a consistent direction of effect, corresponding to gene expression changes in lesional skin of patients. Four of these genes were affected by CNVs in three or more unrelated patients with AA, including ATG4B and SMARCA2, which are involved in autophagy and chromatin remodelling, respectively. Our findings identified new classes of genes with potential contributions to AA pathogenesis.
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Affiliation(s)
- Lynn Petukhova
- Department of Dermatology, College of Physicians and Surgeons, Columbia University, New York, New York.,Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York
| | - Aakash V Patel
- Department of Dermatology, College of Physicians and Surgeons, Columbia University, New York, New York
| | - Rachel K Rigo
- Department of Dermatology, College of Physicians and Surgeons, Columbia University, New York, New York
| | - Li Bian
- Department of Dermatology, College of Physicians and Surgeons, Columbia University, New York, New York
| | - Miguel Verbitsky
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York
| | - Simone Sanna-Cherchi
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York
| | - Stephanie O Erjavec
- Department of Dermatology, College of Physicians and Surgeons, Columbia University, New York, New York.,Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, New York, New York
| | - Alexa R Abdelaziz
- Department of Dermatology, College of Physicians and Surgeons, Columbia University, New York, New York
| | - Jane E Cerise
- Department of Dermatology, College of Physicians and Surgeons, Columbia University, New York, New York
| | - Ali Jabbari
- Department of Dermatology, College of Physicians and Surgeons, Columbia University, New York, New York
| | - Angela M Christiano
- Department of Dermatology, College of Physicians and Surgeons, Columbia University, New York, New York.,Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, New York, New York
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4
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Yao S, Hu Q, Kerns S, Yan L, Onitilo AA, Misleh J, Young K, Lei L, Bautista J, Mohamed M, Mohile SG, Ambrosone CB, Liu S, Janelsins MC. Impact of chemotherapy for breast cancer on leukocyte DNA methylation landscape and cognitive function: a prospective study. Clin Epigenetics 2019; 11:45. [PMID: 30867049 PMCID: PMC6416954 DOI: 10.1186/s13148-019-0641-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 02/28/2019] [Indexed: 12/12/2022] Open
Abstract
Background Little is known about the effects of chemotherapeutic drugs on DNA methylation status of leukocytes, which may be predictive of treatment benefits and toxicities. Based on a prospective national study, we characterize the changes in leukocyte DNA methylome from pre- to post-chemotherapy (approximately 4 months apart) in 93 patients treated for early stage breast cancer and 48 matched non-cancer controls. We further examined significant methylation changes with perceived cognitive impairment, a clinically significant problem related to cancer and chemotherapy. Results Approximately 4.2% of the CpG sites measured using the Illumina 450K methylation array underwent significant changes after chemotherapy (p < 1e-7), in comparison to a stable DNA methylome in controls. Post-chemotherapy, the estimated relative proportions of B cells and CD4+ T cells were decreased by a median of 100% and 39%, respectively, whereas the proportion of monocytes was increased by a median of 91%. After controlling for leukocyte composition, 568 CpGs from 460 genes were still significantly altered following chemotherapy. With additional adjustment for chemotherapy regimen, cumulative infusions, growth factors, and steroids, changes in four CpGs remained significant, including cg16936953 in VMP1/MIR21, cg01252023 in CORO1B, cg11859398 in SDK1, and cg19956914 in SUMF2. The most significant CpG, cg16936953, was also associated with cognitive decline in breast cancer patients. Conclusions Chemotherapy profoundly alters the composition and DNA methylation landscape of leukocytes in breast cancer patients. Our results shed light on the epigenetic response of circulating immune cell populations to cytotoxic chemotherapeutic drugs and provide possible epigenetic links to the degeneration of cognitive function associated with chemotherapy. Electronic supplementary material The online version of this article (10.1186/s13148-019-0641-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Song Yao
- Department of Cancer Prevention and Control, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA.
| | - Qiang Hu
- Department of Biostatistics and Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Sarah Kerns
- Department of Radiation Oncology, University of Rochester, Rochester, NY, USA
| | - Li Yan
- Department of Biostatistics and Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | | | | | | | - Lianlian Lei
- Department of Public Health Sciences, University of Rochester, Rochester, NY, USA
| | - Javier Bautista
- Department of Surgery, Cancer Control, University of Rochester, Rochester, NY, USA.,James P Wilmot Cancer Institute, Rochester, NY, USA
| | - Mostafa Mohamed
- Department of Medicine, University of Rochester, Rochester, NY, USA.,James P Wilmot Cancer Institute, Rochester, NY, USA
| | - Supriya G Mohile
- Department of Medicine, University of Rochester, Rochester, NY, USA.,James P Wilmot Cancer Institute, Rochester, NY, USA
| | - Christine B Ambrosone
- Department of Cancer Prevention and Control, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Song Liu
- Department of Biostatistics and Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA.
| | - Michelle C Janelsins
- Department of Surgery, Cancer Control, University of Rochester, Rochester, NY, USA. .,James P Wilmot Cancer Institute, Rochester, NY, USA.
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5
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Mohandas N, Bass-Stringer S, Maksimovic J, Crompton K, Loke YJ, Walstab J, Reid SM, Amor DJ, Reddihough D, Craig JM. Epigenome-wide analysis in newborn blood spots from monozygotic twins discordant for cerebral palsy reveals consistent regional differences in DNA methylation. Clin Epigenetics 2018; 10:25. [PMID: 29484035 PMCID: PMC5824607 DOI: 10.1186/s13148-018-0457-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 02/12/2018] [Indexed: 12/21/2022] Open
Abstract
Background Cerebral palsy (CP) is a clinical description for a group of motor disorders that are heterogeneous with respect to causes, symptoms and severity. A diagnosis of CP cannot usually be made at birth and in some cases may be delayed until 2–3 years of age. This limits opportunities for early intervention that could otherwise improve long-term outcomes. CP has been recorded in monozygotic twins discordant for the disorder, indicating a potential role of non-genetic factors such as intrauterine infection, hypoxia-ischaemia, haemorrhage and thrombosis. The aim of this exploratory study was to utilise the discordant monozygotic twin model to understand and measure epigenetic changes associated with the development of CP. Methods We performed a genome-wide analysis of DNA methylation using the Illumina Infinium Human Methylation 450 BeadChip array with DNA from newborn blood spots of 15 monozygotic twin pairs who later became discordant for CP. Quality control and data preprocessing were undertaken using the minfi R package. Differential methylation analysis was performed using the remove unwanted variation (RUVm) method, taking twin pairing into account in order to identify CP-specific differentially methylated probes (DMPs), and bumphunter was performed to identify differentially methylated regions (DMRs). Results We identified 33 top-ranked DMPs based on a nominal p value cut-off of p < 1 × 10−4 and two DMRs (p < 1 × 10−3) associated with CP. The top-ranked probes related to 25 genes including HNRNPL, RASSF5, CD3D and KALRN involved in immune signalling pathways, in addition to TBC1D24, FBXO9 and VIPR2 previously linked to epileptic encephalopathy. Gene ontology and pathway analysis of top-ranked DMP-associated genes revealed enrichment of inflammatory signalling pathways, regulation of cytokine secretion and regulation of leukocyte-mediated immunity. We also identified two top-ranked DMRs including one on chromosome 6 within the promoter region of LTA gene encoding tumour necrosis factor-beta (TNF-β), an important regulator of inflammation and brain development. The second was within the transcription start site of the LIME1 gene, which plays a key role in inflammatory pathways such as MAPK signalling. CP-specific differential DNA methylation within one of our two top DMRs was validated using an independent platform, MassArray EpiTyper. Conclusions Ours is the first epigenome-wide association study of CP in disease-discordant monozygotic twin pairs and suggests a potential role for immune dysfunction in this condition. Electronic supplementary material The online version of this article (10.1186/s13148-018-0457-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Namitha Mohandas
- Environmental and Genetic Epidemiology Research, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052 Australia.,2Department of Paediatrics, The University of Melbourne, Flemington Road, Parkville, Victoria 3052 Australia
| | - Sebastian Bass-Stringer
- Environmental and Genetic Epidemiology Research, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052 Australia
| | - Jovana Maksimovic
- 2Department of Paediatrics, The University of Melbourne, Flemington Road, Parkville, Victoria 3052 Australia.,Bioinformatics Group, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052 Australia
| | - Kylie Crompton
- 2Department of Paediatrics, The University of Melbourne, Flemington Road, Parkville, Victoria 3052 Australia.,4Developmental Disability and Rehabilitation Research, Murdoch Children's Research Institute, Flemington Road, Parkville, Victoria 3052 Australia.,5Neurodevelopment and Disability, The Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052 Australia
| | - Yuk J Loke
- Environmental and Genetic Epidemiology Research, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052 Australia
| | - Janet Walstab
- 2Department of Paediatrics, The University of Melbourne, Flemington Road, Parkville, Victoria 3052 Australia.,4Developmental Disability and Rehabilitation Research, Murdoch Children's Research Institute, Flemington Road, Parkville, Victoria 3052 Australia
| | - Susan M Reid
- 2Department of Paediatrics, The University of Melbourne, Flemington Road, Parkville, Victoria 3052 Australia.,4Developmental Disability and Rehabilitation Research, Murdoch Children's Research Institute, Flemington Road, Parkville, Victoria 3052 Australia.,5Neurodevelopment and Disability, The Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052 Australia
| | - David J Amor
- 2Department of Paediatrics, The University of Melbourne, Flemington Road, Parkville, Victoria 3052 Australia.,4Developmental Disability and Rehabilitation Research, Murdoch Children's Research Institute, Flemington Road, Parkville, Victoria 3052 Australia.,5Neurodevelopment and Disability, The Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052 Australia
| | - Dinah Reddihough
- 2Department of Paediatrics, The University of Melbourne, Flemington Road, Parkville, Victoria 3052 Australia.,4Developmental Disability and Rehabilitation Research, Murdoch Children's Research Institute, Flemington Road, Parkville, Victoria 3052 Australia.,5Neurodevelopment and Disability, The Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052 Australia
| | - Jeffrey M Craig
- Environmental and Genetic Epidemiology Research, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052 Australia.,2Department of Paediatrics, The University of Melbourne, Flemington Road, Parkville, Victoria 3052 Australia.,6Centre for Molecular and Medical Research, School of Medicine, Deakin University, Geelong, Victoria 3220 Australia
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