Your Genes, Your Health Books by Aubrey Milunsky, M.D., D.Sc. Know Your Genes Choices, Not Chances How to Have the Healthiest Baby You Can Heredity and Your Family’s Health Your Genetic Destiny , Perseus Publishing And Medical Texts (as Author, Co-Author, or Editor) Th e Prenatal Diagnosis of Hereditary Disorders Th e Prevention of Genetic Disease and Mental Retardation Coping with Crisis and Handicap Clinics in Perinatology Advances in Perinatal Medicine Genetics and the Law (3 Editions) Genetic Disorders and the Fetus: Diagnosis, Prevention and Treatment (6 editions) Your Genes, Your Health A Critical Family Guide Th at Could Save Your Life A ubrey Milunsky, MD, DSc 1 1 Oxford University Press, Inc., publishes works that further Oxford University’s objective of excellence in research, scholarship, and education. Oxford New York Auckland Cape Town Dar es Salaam Hong Kong Karachi Kuala Lumpur Madrid Melbourne Mexico City Nairobi New Delhi Shanghai Taipei Toronto With offi ces in Argentina Austria Brazil Chile Czech Republic France Greece Guatemala Hungary Italy Japan Poland Portugal Singapore South Korea Switzerland Th ailand Turkey Ukraine Vietnam Copyright © 2012 by Aubrey Milunsky, M.D., D.Sc. Published by Oxford University Press, Inc. 198 Madison Avenue, New York, New York 10016 Oxford is a registered trademark of Oxford University Press Oxford University Press is a registered trademark of Oxford University Press, Inc. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior permission of Oxford University Press, Inc. Library of Congress Cataloging-in-Publication Data Milunsky, Aubrey. Your genes, your health : a critical family guide that could save your life / Aubrey Milunsky. p. cm. Includes bibliographical references and index. ISBN 978-0-19-979207-8 (hardback : alk. paper) 1. Medical genetics—Popular works. I. Title. RB155.M55 2011 616'.042—dc22 2010049059 Printing number: 9 8 7 6 5 4 3 2 1 Printed in the United States of America on acid-free paper TO JEFF. For the joy of being your Dad. For the pride in your achievements. For the admiration of you as a father. This page intentionally left blank If, of all the words of tongue and pen, Th e saddest are, “It might have been,” More sad are these we daily see: “It is, but hadn’t ought to be.” — Francis Bret Harte in “Mrs. Judge Jenkins” This page intentionally left blank contents Preface xi Acknowledgments xv 1. Why and What You Should Know 3 2. Too Many or Too Few Chromosomes 14 3. X’s and Y’s: Th e Sex Chromosomes 26 4. Chromosome Rearrangements 39 5. Blueprints: You and Your Genes 50 6. How Genes are Transmitted 65 7. Prenatal Diagnosis 84 8. When Good Cells Go Wrong 105 9. Matters of the Heart 126 10. Consequences of Failure to Diagnose 141 11. Genes Gone Missing 151 12. Earlier and More Severe Genetic Disorders 164 13. Th e Determination to Have a Healthy Child 173 14. Irrevocability and Acceptance 183 15. Ancestral Genetic Burdens 193 16. Puzzling Fevers 213 17. Bleeding and Clotting 220 18. Blood Vessels that Burst 239 19. Brain Connections and Disconnections 250 20. Skin: A Mirror to the Brain 266 21. Genes with Signatures 275 22. Maternal Inheritance and Inevitability 283 ix