Technologies for Detecting Heritable Mutations in Human Beings September 1986 NTIS order #PB87-140158 Recommended Citation: U.S. Congress, Office of Technology Assessment, Technologies for Detecting Heritable Mutations in Human Beings, OTA-H-298 (Washington, DC: U.S. Government Printing Office, September 1986). Library of Congress Catalog Card Number 86-600523 For sale by the Superintendent of Documents U.S. Government Printing Office, Washington, DC 20402 Foreword Ensuring the health of future generations of children is of obvious importance to American society. Heritable mutations, permanent changes in the genetic material that can be passed on to succeeding generations, are the cause of a large but currently un- quantifiable share of embryonic and fetal loss, disease, disability, and early death in the United States today. The methods now available to study heritable mutations, however, offer relatively little information about the kinds of mutations that can oc- cur, their frequency, or their causes. Recent advances in molecular genetics have opened the door to new and innovative technologies that may offer a great deal more informa- tion about DNA. It may soon be possible to characterize mutations precisely, to meas- ure their frequency, and perhaps also to associate particular mutations with exposures to specific mutagenic influences. While some of the new technologies are still on the drawing board, they are developing quickly and several of them may become available for wide-scale use in the next 5 to 10 years. The Senate Committee on Veterans’ Affairs, the House Committee on Science and Technology, and the House Committee on Energy and Commerce requested that OTA assess the available information about current and proposed means for detecting heritable mutations and on the likelihood and potential impact of such technological advances. These committees have wrestled with the problems of determining whether past exposures to potential mutagens have affected the health of Americans, and of framing reason- able public health laws, given current knowledge and technologies. This report sum- marizes OTA’s findings as they relate to these issues. An advisory panel, chaired by Arno G. Motulsky, provided guidance and assis- tance during the assessment. The OTA Health Program Advisory Committee, OTA staff, and scientific and policy experts from the private sector, academia, and the Fed- eral Government provided information during the assessment and reviewed drafts of the report. We thank all who assisted us. As with all OTA reports, the content of the assessment is the sole responsibility of OTA and does not necessarily constitute the con- sensus or endorsement of the advisory panel or the Technology Assessment Board. Key OTA staff involved in the assessment were Michael Gough, Julie Ostrowsky, and Hellen Gelband, JOHN H. GIBBONS Director Ill Advisory Panel for Technologies for Detecting Heritable Mutations in Human Beings Arno G. Motulsky, Panel Chair Center for Inherited Diseases University of Washington School of Medicine Richard J. Albertini Jeffrey H. Miller Department of Medicine Department of Biology University of Vermont University of California at Los Angeles College of Medicine James V. Neel Michael S. Baram Department of Human Genetics School of Medicine and Public Health University of Michigan School of Medicine Boston University Norton Nelson Charles R. Cantor Department of Environmental Medicine Department of Human Genetics and New York University School of Medicine Development Mark L. Pearson Columbia University College of Physicians E.I. du Pent de Nemours & Co. and Surgeons Richard K. Riegelman Dale Hattis Department of Medicine Center for Policy Alternatives George Washington University School of Massachusetts Institute of Technology Medicine Ernest B. Hook Liane B. Russell Bureau of Maternal and Child Health Oak Ridge National Laboratory New York State Department of Health Richard B. Setlow Alfred G. Knudson, Jr. Brookhaven National Laboratory Institute for Cancer Research Fox Chase Cancer Center William J. Schull The University of Texas Health Science Center Nan M. Laird Department of Biological Statistics William G. Thilly Harvard University Department of Nutrition and Food Science School of Public Health Massachusetts Institute of Technology Mortimer L. Mendelssohn Richard M. Myers, Special Consultant Lawrence Livermore National Laboratory University of California at San Francisco NOTE: OTA appreciates and is grateful for the valuable assistance and thoughtful critiques provided by the advisory panel members. The panel does not, however, necessarily approve, disapprove, or endorse this report. OTA assumes full responsibility for the report and the accuracy of its contents. iv OTA Project Staff—Technologies for Detecting Heritable Mutations in Human Beings Roger C. Herdman, Assistant Director, OTA Health and Life Sciences Division Clyde J. Behney, Health Program Manager Michael Gough, Project Director Julia T. Ostrowsky, Analyst Hellen Gelband, Analyst Other Contributing Staff Cheryl M. Corsaro, Analystl Virginia Cwalina, Administrative Assistant Carol Ann Guntow, Secretary/Word Processor Specialist Diann G. Hohenthaner, Word Processor/P. C. Specialist Eric Passaglia, Senior Distribution Specialist Contractors Elbert Branscomb, Lawrence Livermore National Laboratory Neal Cariello, Massachusetts Institute of Technology Leonard Lerman, Genetics Institute Harvey Mohrenweiser, University of Michigan Medical School Richard M. Myers, University of California at San Francisco Janice A. Nicklas, University of Vermont School of Medicine Maynard Olson, Washington University Medical School Cassandra Smith, Columbia University College of Physicians and Surgeons L.H.T. Van der Ploeg, Columbia University College of Physicians and Surgeons Diane K. Wagener, Washington, DC ‘On detail from the National Institutes of Healthr April-June 1985. Contents 1. Summary and Options. 3 2. Genetic Inheritance and Mutations . 23 3. Kinds and Rates of Human Heritable Mutations . 37 4. New Technologies for Detecting Heritable Mutations . 55 5. New Methods for Measuring Somatic Mutations . 73 6. Laboratory Determination of Heritable Mutation Rates . 81 7. Extrapolation . 91 8. Mutation Epidemiology . ..................103 9. Mutagens: Regulatory Considerations. .......113 Appendixes Page A. Federal Spending formulation Research . ...........................121 B. Acknowledgments and Health Program Advisory Committee . .................123 References . .. ....129 Index . .139 Glossary of Acronyms and Terms Glossary of Acronyms RFLP —Restriction Fragment Length Poly- morphism A —Adenine RNA —Ribonucleic Acid AEC —Atomic Energy Commission SCE —Sister-chromatid Exchange ATSDR —Agency for Toxic Substances and Dis- SLT —Specific Locus Test ease Registry (Centers for Disease Control) T —Thymine r BEIR –Committee on the Biological Effects of TG —Thioguanine resistant Ionizing Radiations (NRC) TSCA —Toxic Substances Control Act c —Cytosine UNSCEAR—United Nations Scientific Committee on CERCLA —Comprehensive Environmental Response, the Effects of Atomic Radiation Compensation, and Liability Act 2DDGGE —Two Dimensional Denaturing Gel Elec- (“Superfund”) trophoresis DNA —Deoxyribonucleic Acid 2DPAGE —Two Dimensional Polyacrylamide Gel DOE —Department of Energy Electrophoresis EBV —Epstein-Barr Virus 6TG —6Thioguanine r EDB —Ethylene dibromide 6TG —6Thioguanine resistant EPA —Environmental Protection Agency ENU —Ethylnitrosourea Glossary of Terms EtO —Ethylene oxide FDA –Food and Drug Administration (DHHS) Achondroplasia: A disease marked by a defect in the FRC —Federal Radiation Council formation of cartilage at the ends of long bones (fe- G —Guanine mur, humerus) that leads to a type of dwarfism. HbA —Hemoglobin A There are a number of hereditary forms, the most HbM —Hemoglobin M common of which is autosomal dominant. hprt —Hypoxanthineguanine phosphoribosyl Allele: An alternative form of a gene, or a group of transferase (gene) functionally related genes, located at the corre- HPRT —Hypoxanthineguanine phosphoribosyl sponding site on a homologous chromosome. Each transferase (enzyme) allele is inherited separately from each parent. HTT —Heritable Translocation Test Alleles can be dominant, recessive, or co-dominant ICPEMC —International Commission for Protection for a particular trait. Against Environmental Mutagens and Alpha thalassemia: A genetic defect caused by an Carcinogens alteration in a portion of the gene coding for the ICRP —International Commission on Radiolog- alpha globin molecule. The result is an insufficient ical Protection number of alpha globin molecules and a deficiency mRNA –Messenger RNA of adult hemoglobin. MSHA —Mine Safety and Health Administration Amino acid: One of a group of 20 molecules that bind (Department of Labor) together in various sequences to form all protein NCRP —National Council on Radiation Protec- molecules. The specific sequence of amino acids tion and Measurements determines the structure and function of a protein. NIH —National Institutes of Health Amniocentesis: A procedure that involves withdraw- NRC —Nuclear Regulatory Commission ing a sampIe (usually 2 to 8 miIliIiters) of the amniotic NRC —National Research Council (National fluid surrounding the fetus in utero. This fluid con- Academy of Sciences) tains cells shed by the developing fetus. The cells NTP –National Toxicology Program (DHHS) can be grown in cell culture and analyzed either bio- OSHA –Occupational Safety and Health Admin- chemically