Large-Scale, Unbiased Genetics: Pulling Psychiatry into the 21st Century Steven E. Hyman Harvard University Stanley Center/Broad Institute A Collaboration of Massachusetts Institute of Technology, Harvard University and the Harvard-Affiliated Hospitals Psychiatric Disorders are Common and Disabling Burden of Diseases, Injuries, and Risk Factors, U.S.1990-2010: Years lived with disability by age and disease class Unintentional Injuries Musculoskeletal Mental Disorders : Source: JAMA 2013 doi:10.1001/jama2013.13805 Date of download: 7/13/2013 Copyright © 2012 American Medical Association. All rights reserved. www.broadinstitute.org/psych/stanley Schizophrenia Highly heritable brain disease characterized by adolesce gray matter loss, cognitive impairment, psychosis Excessive gray matter loss in adolescents with schizophrenia Source : Vidal et al Arch Gen Psychiatry 2006, 63:25-3 www.broadinstitute.org/psych/stanley Current drugs for neuropsychiatric disorders have the same targets as 1950’s prototypes There are no pharmacologic treatments for the core symptoms of autism or for the deficit or cognitive symptoms of schizophrenia www.broadinstitute.org/psych/stanley Despite high prevalence and vast unmet need industry has deemphasized psychiatry • Lack of new molecular targets • Animal models do not predict efficacy • Human brain inaccessible to direct study in life • No validated biomarkers; descriptive diagnoses www.broadinstitute.org/psych/stanley Technology and computation make it possible to right the research enterprise Technological revolution of last decade Genomic and computational technologies • Stem cell technologies • Genome engineering technologies • Tools for systems-level neurobiology • New forms of organization for science Durable consortia for genetic and other large-scale studies • Large, shared datasets • Biobanks • Interdisciplinary collaborative networks • www.broadinstitute.org/psych/stanley High heritabilities mean molecular clues to pathogenesis lie within our genomes Heritabilities derived from twin studies λ1 heritability Autism 25 0.65-0.8 Schizophrenia 9 0.8 Bipolar Disorder 8 0.7-0.8 2-5 0.35 Disorder Major Depression Source: Sullivan, Daly, O’Donovan 2012 www.broadinstitute.org/psych/stanley http://www.broadinstitute.org/psych/stanley Genetic architecture of psychiatric disorders Polygenicity Hundreds of risk genes and thousands of alleles to interrogate Heterogeneity Diverse genetic paths to illness; heterogeneous phenotypes (spectra not categories) Low Penetrance Alleles Pleiotropic Effects Penetrance of individual risk alleles modest. Even large CNVs have incomplete penetrance and increase λ by only 10-20x Shared genetic risk across neuropsychiatric disorders. Even large CNVs have variable expressivity when penetrant www.broadinstitute.org/psych/stanley Fecundity of Patients With Schizophrenia, Autism, BPD, Depression, Anorexia Nervosa, or Substance Abuse Ramifications: Common and low frequency variants can be plentiful at very low effect sizes (OR < 1.1) Transmission of large effect alleles must be extremely rare Fertility ratios for individuals with by disorder and gender. A fertility ratio of 1 represents that of the general population. Source: Power et al. JAMA Psychiatry. 2013;70(1):2 Date of download: 3/5/2014 Copyright © 2014 American Medical Association. All rights reserved. www.broadinstitute.org/psych/stanley New technology and global collaboration have made large-scale, unbiased genetic studies possible Samples: robotics, two-dimensional barcoding Inexpensive microarrays for common variants Sequencing exomes and genomes for rare variants www.broadinstitute.org/psych/stanley Technology makes it possible to address both common and rare variation at the needed scale Inexpensive microarrays for ancient common variants Sequencing for rare variants less subjected to natural selection Ancient variation that is common across populations www.broadinstitute.org/psych/stanley Genome-wide common variant association in schizophrenia in 2009 (4,000 cases) “ www.broadinstitute.org/psych/stanley Relationship of sample size to genomewide significant findings www.broadinstitute.org/psych/stanley Genome-wide common variant association in schizophrenia in 2011 (10,000 cases) www.broadinstitute.org/psych/stanley PGC schizophrenia Common Variant Association; 37,000 cases ORs average approximately 1.08 www.broadinstitute.org/psych/stanley Global Collaborations are Required for Effective Sample Collection www.broadinstitute.org/psych/stanley Sequencing to find rare, protein-altering alleles Trio studies Sequencing to find new, protein-altering mutations in father-mother-proband autism and schizophrenia trios cases controls Case-control studies Sequencing to find genes for which rare, proteindamaging mutations are more common in cases than controls www.broadinstitute.org/psych/stanley Rare Variant Association Human exomes are teeming with variation: It is easy to find rare variants, but hard to establish disease associations ~20,000 variants in or near protein coding genes. ~200 are missense ~100 are loss-of-function (deletions, single-nucleotide variants) of which ~20 are very rare or private Plan: Sequencing “surge” across diverse human populatons www.broadinstitute.org/psych/stanley Genetics update Datasets coming on board (estimates) Schizophrenia Year GWAS Exome Seq Genome Seq 2015 ~60K cases 6K cases 1K cases 2016-2017 ~80K cases 20K cases 5K cases 2018-2019 >100K cases Year GWAS Exome Seq Genome Seq 2015 ~18K cases 6K cases None 2016-2017 ~20K cases 15K cases 500 cases 2018-2019 ~22K cases 20K cases ~1K cases 40K cases Autism 10K cases Note: Balance between exome and whole genome sequencing will be influenced by c 19| SC – NVS JSC Informatics workstream | February 19, 2015 | Business Use Only www.broadinstitute.org/psych/stanley Epilepsy: ILAE Consortium Meta-Analysis 2014 Source: Lancet Neurology 2014 www.broadinstitute.org/psych/stanley Why do we care about alleles of small effect? They are our best tools to glean biological clues Risk alleles identify disease-relevant genes Genes identify pathways and protein networks These illuminate disease mechanisms and suggest drug targets Statins act on HMG CoA-reductase www.broadinstitute.org/psych/stanley An initial ‘parts list’ for schizophrenia Voltage-gated calcium channels CACNA1C CACNA1D CACNA1I CACNB2 CACNB3 Selective protein degradation KCTD13 UBE3A Cytoskeleton and synapse assembly GIT1 SYNGAP1 ITSN1 Glutamate/NMDA signaling GRIA1 GRIN2A GRIN2B GRM3 NRGN Immune system related proteins Complement components www.broadinstitute.org/psych/stanley We need good high throughput, evolutionarily appropriate living systems Poor access to human brain tissue in life Rodent models poor for • • • Dividing human cancer cell from excision High throughput studies Studying noncoding sequences: poorly conserved compared with exons Modeling diseases that affect evolutionarily recent cell types and circuits www.broadinstitute.org/psych/stanley Stem cell technology enables high throughput systems expressing human transcriptional networks Differentiate iPSCs phenotype hESCs Build circuits CRISPR: add risk variants or rescue patient cells Small molecule Screens Compare genetic rescue to small molecule effects www.broadinstitute.org/psych/stanley Search for translatable phenotypes 90 myr 40 myr www.broadinstitute.org/psych/stanley The human model for the human Assuming that toxicity has been tested in animals, can we take a central nervous system (CNS) drug into humans that has only been tested in cellular models? The issues are both ethical and pragmatic (will companies invest without animal ‘efficacy gate’?) www.broadinstitute.org/psych/stanley An entire community has come together around these efforts Broad Institute, Harvard, & MIT Genetics Stem Cells Steve McCarroll Kevin Eggan Mark Daly Paola Arlotta Ben Neale Lee Rubin Aarno Palotie Karestan Koenen Therapeutics and Clinical Trials Elise Robinson Ed Scolnick Shaun Purcell Ed Holson Stephan Ripke Roy Perlis Giulio Genovese Maurizio Fava Jennifer Moran Yan-ling Zhang Jon Madison Neurobiology Guoping Feng Proteomics Jen Pan Wade Harper Bernardo Sabatini Kasper Laage Zhanyan Fu Genome Engineering Feng Zhang Neuroimmunology Beth Stevens Karolinska Institute Christina Hultman Mikael Landen Anna Kahler iPsych Denmark Bo Preben Mortensen Cardiff University Michael O’Donovan Michael Owen George Kirov Nick Craddock Mt. Sinai College of Medicine Pamela Sklar Johns Hopkins Rick Huganir Akira Sawa Novartis Institute for Biomedical Research Ricardo Dolmetsch UNC-Chapel Hill Patrick Sullivan USC Carlos Pato Michele Pato Jim Knowles University of Capetown Dan Stein Mexico City Maria Elena Medina Mora New Collaborations Japan Finland Funding Stanley Medical Research Institut Kent and Liz Dauten NIH (NHGRI, NIMH) www.broadinstitute.org/psych/stanley