Gale Encyclopedia of Medicine Vol 4 2nd ed pdf

  GALE The

  

ENCYCLOPEDIA

M EDICINE of

  The GALE

ENCYCLOPEDIA

of

  M EDICINE

SECOND EDITION

J A C Q U E L I N E L . L O N G E , E D I T O R

  

D E I R D R E S . B L A N C H F I E L D , A S S O C I A T E E D I T O R

  

V O L U M E

N-S

  

4

  STAFF Jacqueline L. Longe, Project Editor Deirdre S. Blanchfield, Associate Editor Christine B. Jeryan, Managing Editor Donna Olendorf, Senior Editor Stacey Blachford, Associate Editor Kate Kretschmann, Melissa C. McDade, Ryan

  Since this page cannot legibly accommodate all copyright notices, the acknowledgments constitute an extension of the copyright notice. While every effort has been made to ensure the reliability of the infor- mation presented in this publication, the Gale Group neither guarantees the accuracy of the data contained herein nor assumes any responsibili- ty for errors, omissions or discrepancies. The Gale Group accepts no payment for listing, and inclusion in the publication of any organiza- tion, agency, institution, publication, service, or individual does not imply endorsement of the editor or publisher. Errors brought to the attention of the publisher and verified to the satisfaction of the publish- er will be corrected in future editions. This book is printed on recycled paper that meets Environmental Pro- tection Agency standards. The paper used in this publication meets the minimum requirements of American National Standard for Information Sciences-Permanence Paper for Printed Library Materials, ANSI Z39.48-1984. This publication is a creative work fully protected by all applicable copyright laws, as well as by misappropriation, trade secret, unfair com- petition, and other applicable laws. The authors and editor of this work have added value to the underlying factual material herein through one or more of the following: unique and original selection, coordination, expression, arrangement, and classification of the information. Gale Group and design is a trademark used herein under license. All rights to this publication will be vigorously defended. Copyright © 2002 Gale Group 27500 Drake Road Farmington Hills, MI 48331-3535 All rights reserved including the right of reproduction in whole or in part in any form.

  2001051245

  II. Blanchfield, Deirdre S. III. Gale Research Company. RC41.G35 2001 616’.003—dc21

  1. Internal medicine—Encyclopedias. I. Longe, Jacqueline L.

  ISBN 0-7876-5489-2 (set: hardcover) — ISBN 0-7876-5490-6 (vol. 1) — ISBN 0-7876-5491-4 (vol. 2) — ISBN 0-7876-5492-2 (vol. 3) — ISBN 0-7876-5493-0 (vol. 4) — ISBN 0-7876-5494-9 (vol. 5)

  Library of Congress Cataloging-in-Publication Data Gale encyclopedia of medicine / Jacqueline L. Longe, editor; Deirdre S. Blanchfield, associate editor — 2nd ed. p. cm. Includes bibliographical references and index. Contents: Vol. 1. A-B — v. 2. C-F — v. 3. G-M — v. 4. N-S — v. 5. T-Z.

  ISBN 0-7876-5489-2 (set) 0-7876-5490-6 (Vol. 1) 0-7876-5491-4 (Vol. 2) 0-7876-5492-2 (Vol. 3) 0-7876-5493-0 (Vol. 4) 0-7876-5494-9 (Vol. 5) Printed in the United States of America 10 9 8 7 6 5 4 3 2 1

  ENCYCLOPEDIA of MEDICINE

SECOND EDITION

  Thomason, Assistant Editors Mark Springer, Technical Specialist Andrea Lopeman, Programmer/Analyst Barbara J. Yarrow, Manager, Imaging and Multimedia

  Dorothy Maki, Manufacturing Manager Wendy Blurton, Senior Manufacturing Specialist The GALE

  Electronic Prepress Evi Seoud, Assistant Manager, Composition Purchasing and Electronic Prepress

  Image Catalogers Pamela A. Reed, Imaging Coordinator Randy Bassett, Imaging Supervisor Robert Duncan, Senior Imaging Specialist Dan Newell, Imaging Specialist Christine O’Bryan, Graphic Specialist Maria Franklin, Permissions Manager Margaret A. Chamberlain, Permissions Specialist Michelle DiMercurio, Senior Art Director Mike Logusz, Graphic Artist Mary Beth Trimper, Manager, Composition and

  Multimedia Content Kelly A. Quin, Editor, Imaging and Multimedia Content Leitha Etheridge-Sims, Mary K. Grimes, Dave Oblender,

  Multimedia Content Dean Dauphinais, Senior Editor, Imaging and

  Content Robyn V. Young, Project Manager, Imaging and

  

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Advisory Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

Entries

  

Volume 1: A-B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

  1 Volume 2: C-F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 625

Volume 3: G-M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1375

Volume 4: N-S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2307

Volume 5: T-Z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3237

  

Organizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3603

General Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3625

CONTENTS The Gale Encyclopedia of Medicine 2 is a medical ref- erence product designed to inform and educate readers about a wide variety of disorders, conditions, treatments, and diagnostic tests. The Gale Group believes the product to be comprehensive, but not necessarily definitive. It is intended to supplement, not replace, consultation with a physician or other healthcare practitioner. While the Gale Group has made substantial efforts to provide information that is accurate, comprehensive, and up-to-date, the Gale Group makes no representations or warranties of any kind, including without limitation, warranties of mer- chantability or fitness for a particular purpose, nor does it guarantee the accuracy, comprehensiveness, or timeliness of the information contained in this product. Readers should be aware that the universe of medical knowledge is constantly growing and changing, and that differences of medical opinion exist among authorities. Readers are also advised to seek professional diagnosis and treatment for any medical condition, and to discuss information obtained from this book with their health care provider.

  

PLEASE READ—IMPORTANT INFORMATION

  

INTRODUCTION

  Definition Definition Description Purpose Causes and symptoms Precautions Diagnosis Description Treatment Preparation Alternative treatment Aftercare Prognosis Risks Prevention Normal/Abnormal results Resources Resources Key terms Key terms

  print hyperlinks that point the reader to related entries in the encyclopedia.

  The Gale Encyclopedia of Medicine 2 has been designed with ready reference in mind.

  The essays were compiled by experienced medical writers, including physicians, pharmacists, nurses, and other health care professionals. GEM2 medical advisors reviewed the completed essays to insure that they are appropriate, up-to-date, and medically accurate.

  A preliminary list of diseases, disorders, tests and treat- ments was compiled from a wide variety of sources, including professional medical guides and textbooks as well as consumer guides and encyclopedias. The general advisory board, made up of public librarians, medical librarians and consumer health experts, evaluated the top- ics and made suggestions for inclusion. The list was sorted by category and sent to GEM2 medical advisors, certified physicians with various medical specialities, for review. Final selection of topics to include was made by the med- ical advisors in conjunction with the Gale Group editor.

  Alternative treatment sections for diseases and condi- tions that may be helped by complementary therapies.

  In recent years there has been a resurgence of interest in holistic medicine that emphasizes the connection between mind and body. Aimed at achieving and main- taining good health rather than just eliminating disease, this approach has come to be known as alternative medi- cine. The Gale Encyclopedia of Medicine 2 includes a number of essays on alternative therapies, ranging from traditional Chinese medicine to homeopathy and from meditation to aromatherapy. In addition to full essays on alternative therapies, the encyclopedia features specific

  Disorders/Conditions Tests/Treatments

  The Gale Encyclopedia of Medicine 2 (GEM2) is a one-stop source for medical information on nearly 1,700 common medical disorders, conditions, tests, and treat- ments, including high-profile diseases such as AIDS, Alzheimer’s disease, cancer, and heart attack. This ency- clopedia avoids medical jargon and uses language that laypersons can understand, while still providing thor- ough coverage of each topic. The Gale Encyclopedia of

  Many common drugs are also covered, with generic drug names appearing first and brand names following in parentheses, eg. acetaminophen (Tylenol). Throughout the Gale Encyclopedia of Medicine 2, many prominent individuals are highlighted as sidebar biographies that accompany the main topical essays. Articles follow a standardized format that provides information at a glance. Rubrics include:

  Gale Encyclopedia of Medicine 2 , including disorders/ conditions, tests/procedures, and treatments/therapies.

  Almost 1,700 full-length articles are included in the

  SCOPE

  fills a gap between basic consumer health resources, such as single-volume family medical guides, and highly technical professional materials.

  Medicine 2

• Straight alphabetical arrangement allows users to locate information quickly.
• Bold-faced terms function as

  Cross-references placed throughout the encyclopedia Resources section directs users to additional sources

• direct readers to where information on subjects with- of medical information on a topic. out entries can be found. Synonyms are also cross-ref-
• A comprehensive general index allows users to easily

  oduction erenced.

  target detailed aspects of any topic, including Latin

  Intr names.

• A list of key terms are provided where appropriate to define unfamiliar terms or concepts.

  GRAPHICS

• Valuable contact information for organizations and support groups is included with each entry. The The Gale Encyclopedia of Medicine 2 is enhanced appendix contains an extensive list of organizations with over 675 color images, including photos, charts, arranged in alphabetical order. tables, and customized line drawings.

ADVISORY BOARD

  Elizabeth Clewis Crim, MLS Collection Specialist

  Lecturer on Psychiatry

  Harvard Medical School Cambridge, MA Lee A. Shratter, M.D.

  Staff Radiologist

  The Permanente Medical Group Richmond, CA Amy B. Tuteur, M.D.

  Sharon, MA

  LIBRARIAN ADVISORS Maureen O. Carleton, MLIS Medical Reference Specialist

  King County Library System Bellevue, WA

  Prince William Public Library, VA

  Clinical Professor of Psychiatry

  Valerie J. Lawrence, MLS Assistant Librarian

  Western States Chiropractic College

  Portland, OR

  Barbara J. O’Hara, MLS Adult Services Librarian

  Free Library of Philadelphia, PA

  Alan M. Rees, MLS Professor Emeritus

  Case Western Reserve University Cleveland, OH

  

A number of experts in the library and medical communities provided invaluable assistance in the formulation of this ency-

clopedia. Our advisory board performed a myriad of duties, from defining the scope of coverage to reviewing individual

entries for accuracy and accessibility. The editor would like to express her appreciation to them.

  Tufts University School of Medicine Boston, MA

  Clinical Assistant Professor of Medicine

  Division of Oncology Stanford University

  Lathrup Village, MI L. Anne Hirschel, D.D.S. Southfield, MI

Larry I. Lutwick M.D., F.A.C.P.

  Director of Medical Oncology

  Community Hospital of Los Gatos- Saratoga

  Los Gatos, CA Laurie Barclay, M.D. Neurological Consulting Services Tampa, FL Kenneth J. Berniker, M.D.

  Attending Physician

  Emergency Department Kaiser Permanente Medical Center Vallejo, CA Rosalyn Carson-DeWitt, M.D.

  Durham, NC Robin Dipasquale, N.D. Clinical Faculty Bastyr University Seattle, WA Faye Fishman, D.O. Randolph, NJ J. Gary Grant, M.D. Pacific Grove, CA Laith F. Gulli, M.D. M.Sc., M.Sc.(MedSci), MSA,

  Msc.Psych., MRSNZ FRSH, FRIPHH, FAIC, FZS DAPA, DABFC, DABCI

  Consultant Psychotherapist in Private Practice

  Director, Infectious Diseases

  Medical College of Pennsylvania– Hahnemann University

  VA Medical Center Brooklyn, NY

  Ira Michelson, M.D., M.B.A., F.A.C.O.G.

  

Physician and Clinical Instructor

  University of Michigan Ann Arbor, MI Susan Mockus, M.D.

  Scientific Consultant

  Seattle, WA

  Ralph M. Myerson, M.D., F.A.C.P.

  Clinical Professor of Medicine

  Philadelphia, PA Ronald Pies, M.D.

  Margaret Alic, Ph.D.

  Medical Writer

  Genetic Counselor

  Eugene, OR

  Barbara Boughton Health and Medical Writer

  El Cerrito, CA Cheryl Branche, M.D.

  Retired General Practitioner

  Jackson, MS

  Michelle Lee Brandt Medical Writer

  San Francisco, CA Maury M. Breecher, Ph.D.

  Health Communicator/Journalist

  Northport, AL

  Ruthan Brodsky Medical Writer

  Bloomfield Hills, MI Tom Brody, Ph.D.

  Science Writer

  Berkeley, CA Leonard C. Bruno, Ph.D.

  Chevy Chase, MD

  Genetic Counselor

  Diane Calbrese Medical Sciences and Technology Writer

  Silver Spring, Maryland

  Richard H. Camer Editor International Medical News Group

  Silver Spring, MD Rosalyn Carson-DeWitt, M.D.

  Medical Writer

  Durham, NC Lata Cherath, Ph.D.

  Science Writing Intern Cancer Research Institute

  New York, NY

  Linda Chrisman Massage Therapist and Educator

  Oakland, CA Lisa Christenson, Ph.D.

  Science Writer

  Hamden, CT Geoffrey N. Clark, D.V.M.

  Editor Canine Sports Medicine Update

  Newmarket, NH

  Children’s Hospital Oakland Oakland, CA

Michelle Q. Bosworth, M.S., C.G.C.

  Jennifer Bowjanowski, M.S., C.G.C.

  Science Writer

  North York, Ontario Laurie Barclay, M.D.

  Eastsound, WA

  Janet Byron Anderson Linguist/Language Consultant

  Rocky River, OH Lisa Andres, M.S., C.G.C.

  Certified Genetic Counselor and Medical Writer

  San Jose, CA

  Greg Annussek Medical Writer/Editor

  New York, NY Bill Asenjo, M.S., C.R.C.

  Science Writer

  Iowa City, IA Sharon A. Aufox, M.S., C.G.C.

  Genetic Counselor

  Rockford Memorial Hospital Rockford, IL

  Sandra Bain Cushman Massage Therapist, Alexander Technique Practitioner

  Charlottesville, VA

  Howard Baker Medical Writer

  Neurological Consulting Services

  Atlanta, GA

  Tampa, FL

  Jeanine Barone Nutritionist, Exercise Physiologist

  New York, NY

  Julia R. Barrett Science Writer

  Madison, WI Donald G. Barstow, R.N.

  Clincal Nurse Specialist

  Oklahoma City, OK Carin Lea Beltz, M.S.

  Genetic Counselor and Program Director

  The Center for Genetic Counseling Indianapolis, IN Linda K. Bennington, C.N.S.

  Science Writer

  Virginia Beach, VA

  Issac R. Berniker Medical Writer

  Vallejo, CA Kathleen Berrisford, M.S.V.

  Science Writer Bethanne Black Medical Writer

  

CONTRIBUTORS

  Rhonda Cloos, R.N.

  Maureen Haggerty Medical Writer

  Medical Ink St. Paul, MN Karen Ericson, R.N.

  Altha Roberts Edgren Medical Writer

  University of Arizona Tucson, AZ

  Thomas Scott Eagan Student Researcher

  Asheville, NC

  Clare Hanrahan Medical Writer

  Ambler, PA

  Winston-Salem, NC

  Estes Park, CO

  Medical Writer

  Lathrup Village, MI Kapil Gupta, M.D.

  Consultant Psychotherapist in Private Practice

  Msc.Psych, MRSNZ FRSH, FRIPHH, FAIC, FZS DAPA, DABFC, DABCI

  Asheville, NC Laith F. Gulli, M.D. M.Sc., M.Sc.(MedSci), M.S.A.,

  Peter Gregutt Writer

  Silver Spring, MD

  former president, American Massage Therapy Association Massage Therapist

  Medical Writer

  

L. Fleming Fallon Jr., M.D.,

Dr.PH

Associate Professor of Public

Health

  Alison Grant Medical Writer

  Grand Forks, ND

Sallie Freeman, Ph.D., B.S.N.

  New Milford, PA

  Medical Writer

  Manitowoc, WI Ron Gasbarro, Pharm.D.

  Nurse, Medical Writer

  East Rock Institute New Haven, CT Cynthia L. Frozena, R.N.

  Research and Administrative Associate

  Atlanta, GA Rebecca J. Frey, Ph.D.

  Medical Writer

  Janie F. Franz Writer

  Bowling Green State University Bowling Green, OH Faye Fishman, D.O.

  Chaplin, MN

  Paula Ford-Martin Medical Writer

  Culver City, CA

  Risa Flynn Medical Writer

  Lexikon Communications Sebastopol, CA

  Janis Flores Medical Writer

  Randolph, NJ

  Physician

  Averill Park, NY Elliot Greene, M.A.

  University of Michigan Ann Arbor, MI

  Medical Writer

  Physician

  Robert S. Dinsmoor Medical Writer

  Sicklerville, NJ

  Lori De Milto Medical Writer

  Mahopac, NY

  Medical Writer/Editor

  Fremont, California Dominic De Bellis, Ph.D.

  Medical Writer

  Brooklyn, NY Tish Davidson, A.M.

  Holbrook, MA Arnold Cua, M.D.

  Medical Writer

  Medical Writer

  Chicago, IL Esther Csapo Rastega, R.N., B.S.N.

  Medical Writer

  Vermillion, SD David A. Cramer, M.D.

  Medical Writer

  Sacramento, CA Amy Cooper, M.A., M.S.I.

  Gloria Cooksey, C.N.E Medical Writer

  Austin, TX

  South Hamilton, MA Stephanie Dionne, B.S.

  Ann Arbor, MI Martin W. Dodge, Ph.D.

  Senior Research Associate

  Playa del Rey, CA Gary Gilles, M.A.

  Germantown, MD Jill Granger, M.S.

  Megan Gourley Writer

  Nazareth, PA

  Debra Gordon Medical Writer

  Old Lyme, CT

  Harry W. Golden Medical Writer Shoreline Medical Writers

  Wauconda, IL

  Medical Writer

  Julie A. Gelderloos Biomedical Writer

  Technical Writer/Editor

  Boulder, CO

  Science Writer

  Milwaukee, WI Doug Dupler, M.A.

  Genetic Counselor

  Salt Lake City, UT Stefanie B. N. Dugan, M.S.

  David Doermann Medical Writer

  Inglewood, CA

  Centinela Hospital and Medical Center

  Contributors

  Ann M. Haren Science Writer

  Lakewood, OH West Chester, PA

  Medical Writer

  Ossining, NY Joseph Knight, P.A.

  Bob Kirsch Medical Writer

  Havertown, PA

  Christine Kuehn Kelly Medical Writer

  Bay Village, OH

  Beth A. Kapes Medical Writer

  Liz Meszaros Medical Writer

  Melissa Knopper Medical Writer

  Montreal, Quebec

  Medical Writer and Editor

  Phoenixville, CA Alison McTavish, M.Sc.

  Mercedes McLaughlin Medical Writer

  Ann Arbor, MI

  Sally C. McFarlane-Parrott Medical Writer

  Greensboro, NC

  Medical Writer

  Winton, CA

  Chicago, IL Karen Krajewski, M.S., C.G.C.

  Fellow, American College of Surgeons Diplomat American Board of Surgery

  Jill Lasker Medical Writer

  San Diego, CA

  Medical Writer

  Huntington Beach, CA Lorraine Lica, Ph.D.

  Biological Consultant

  East Lansing, MI Victor Leipzig, Ph.D.

  Kristy Layman Music Therapist

  Midlothian, VA

  Sabin, MN

  Genetic Counselor

  Physical Therapist

  Philadelphia, PA Jeffrey P. Larson, R.P.T.

  Richard H. Lampert Senior Medical Editor W.B. Saunders Co.

  Spokane, WA

  Jennifer Lamb Medical Writer

  Pittsburgh, PA

  Physician, writer

  Assistant Professor of Neurology Wayne State University Detroit, MI Jeanne Krob, M.D., F.A.C.S.

  Richland, WA Bonny McClain, Ph.D.

  Charlottesville, VA Richard A. McCartney M.D.

  Madison, CT Judy C. Hawkins, M.S.

  Genetic Counselor

  Genetic Counselor

  The Children’s Mercy Hospital Kansas City, MO Dawn A. Jacob, M.S.

  Genetic Counselor

  Morristown, NJ Holly Ann Ishmael, M.S., C.G.C.

  Medical Writer

  Albuquerque, NM Kevin Hwang, M.D.

  University of New Mexico Health Sciences Center

  Boca Raton, FL Katherine S. Hunt, M.S.

  Medical Writer Los Angeles, CA Michelle L. Johnson, M.S., J.D.

  Lisette Hilton Medical Writer

  London, Ontario

  David Helwig Medical Writer

  New Orleans, LA

  Caroline Helwick Medical Writer

  Galveston, TX

  The University of Texas Medical Branch

  Genetic Counselor

  Obstetrix Medical Group of Texas Fort Worth, TX Sally J. Jacobs, Ed.D.

  Patent Attorney and Medical Writer

  Medical Writer

  Suzanne M. Lutwick Medical Writer

  Beloit, WI Ruth E. Mawyer, R.N.

  Medical Writer

  Demarest, NJ Adrienne Massel, R.N.

  Consultant, Molecular Pathology

  Wayne State University Detroit, MI Warren Maltzman, Ph.D.

  Medical Student

  Brooklyn, NY Nicole Mallory, M.S.

  VA Medical Center Brooklyn, NY

  Portland, OR Paul A. Johnson, Ed.M.

  Director, Infectious Diseases

  Utah State University Logan, UT Larry Lutwick, M.D., F.A.C.P.

  Assistant Director, Biotechnology Center

  Medical Writer John T. Lohr, Ph.D.

  Sagescript Communications Lakewood, CO David Kaminstein, M.D.

  Biomedical Writer

  San Diego, CA Cindy L. A. Jones, Ph.D.

  Medical Writer

  Contributors

  Betty Mishkin Medical Writer

  Medical Writer

  Division of Clinical and Metabolic Genetics

  Genetic Counselor

  Phoenix, Arizona

Nada Quercia, M.S., C.C.G.C.

  Medical Writer

  Buffalo Grove, IL Elizabeth J. Pulcini, M.S.

  Medical Writer

  Phoenix, AZ Scott Polzin, M.S., C.G.C.

  South Windsor, CT J. Ricker Polsdorfer, M.D.

  Ann Quigley Medical Writer

  Medical Writer

  Logan, UT Joyce S. Siok, R.N.

  Medical Writer

  Richmond, TX Judith Sims, M.S.

  Writer

  Center for Cancer Risk Analysis Massachusetts General Hospital Boston, MA Kim A. Sharp, M.Ln.

  Genetic Counselor

  Catherine Seeley Medical Writer Kristen Mahoney Shannon, M.S., C.G.C.

  The Hospital for Sick Children Toronto, ON, Canada

  New York, NY Robert Ramirez, B.S.

  Clinical Geneticist

  Evanston, IL

  Moorehead, KY

  Medical Writer

  

Anna Rovid Spickler, D.V.M.,

Ph.D.

  Belleville, MI

  Nancy Ross-Flanigan Science Writer

  Tucson, AZ

  Richard Robinson Medical Writer

  Martha Robbins Medical Writer

  Medical Student

  Salt Lake City, UT

  Toni Rizzo Medical Writer

  Holbrook, MA

  

Registered Nurse, Medical Writer

  

Esther Csapo Rastegari, Ed.M.,

R.N./B.S.N.

  New York, NY

  Medical Doctor and Writer

  University of Medicine & Dentistry of New Jersey Stratford, NJ Kulbir Rangi, D.O.

  Greenwood Genetic Center Greenwood, SC

  Mental Health Marlborough, MA Laurie Heron Seaver, M.D.

  Skokie, IL

  Universidad Iberoamericana Santo Domingo, Domincan

  Ute Park, NM Lisa Papp, R.N.

  Medical Writer

  Minneapolis, MN Teresa Norris, R.N.

  Nancy J. Nordenson Medical Writer

  Weehawken, NJ

  Laura Ninger Medical Writer

  Republic

  Senior Medical Student

  Cherry Hill, NJ

  Huntington Beach, CA Bilal Nasser, M.Sc.

  Louann W. Murray, PhD Medical Writer

  Milwaukee, WI

  Susan J. Montgomery Medical Writer

  Seattle, WA

  Medical Writer

  Hallstead, PA Mark A. Mitchell, M.D.

  Barbara J. Mitchell Medical Writer

  Medical Writer

  Patience Paradox Medical Writer

  Nursing Massachusetts Department of

  Medical, Science, & Technology Writer

  Joan Schonbeck Medical Writer

  Holland, OH

  Chiropractor Holland Chiropractic, Inc.

  Branford, CT Jason S. Schliesser, D.C.

  Technical Writer

  Chicago, IL Kausalya Santhanam, Ph.D.

  Karen Sandrick Medical Writer

  Los Angeles, CA

  Voorheesville, NY Andrea Ruskin, M.D. Whittingham Cancer Center Norwalk, CT Laura Ruth, Ph.D.

  Bainbridge Island, WA

  Medical Writer

  Wheaton, IL Belinda Rowland, Ph.D.

  Collette Placek Medical Writer

  Chicago, IL

  Medical Writer

  Bend, OR Genevieve Pham-Kanter, M.S.

  Genetic Counseling of Central Oregon

  Barbara J. Pettersen Genetic Counselor

  Contributors

  Jennifer Sisk Medical Writer

  East Northport, NY Catherine L. Tesla, M.S., C.G.C.

  Jennifer Wurges Medical Writer

  Rochester Hills, MI Mary Zoll, Ph.D.

  Science Writer

  Newton Center, MA

  Jon Zonderman Medical Writer

  Orange, CA Michael V. Zuck, Ph.D.

  Medical Writer

  Boulder, CO

  Liz Swain Medical Writer

  San Diego, CA

  Deanna M. Swartout-Corbeil, R.N.

  Medical Writer

  Thompsons Station, TN Keith Tatarelli, J.D.

  Medical Writer Mary Jane Tenerelli, M.S. Medical Writer

  Senior Associate, Faculty

  Medical Writer

  Lancaster, PA Judith Turner, B.S.

  Wantagh, NY

  Medical Writer

  Sharon, MA Samuel Uretsky, Pharm.D.

  Medical Advisor

  Sandy, UT Amy B. Tuteur, M.D.

  Medical Writer

  Carol Turkington Medical Writer

  Dept. of Pediatrics, Division of Medical Genetics

  Troy, MI

  Medical Writer

  Rockland, ME Mai Tran, Pharm.D.

  Bethany Thivierge Biotechnical Writer/Editor Technicality Resources

  Atlanta, GA

  Emory University School of Medicine

  Delmar, DE

  Haddonfield, NJ Kathleen D. Wright, R.N.

  Havertown, PA

  Albuquerque, NM Java O. Solis, M.S.

  Canton, OH Lorraine Steefel, R.N.

  Jane E. Spehar Medical Writer

  Little Rock, AR

  Elaine Souder, PhD Medical Writer

  Decatur, GA

  Medical Writer

  Linda Wasmer Smith Medical Writer

  Morganville, NJ

  Portland, OR

  Stephanie Slon Medical Writer

  New Britain, CT

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  Amman, Jordan Genevieve Slomski, Ph.D.

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  University of Arizona Tucson, AZ Ronald Watson, Ph.D.

  Laguna Hills, CA Jennifer F. Wilson, M.S.

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  Dorothy Stonely Medical Writer

  Greenwood Genetic Center Greenwood, SC

  Director

  Contributors Nail infections see Onychomycosis

  Nail-patella syndrome, is a genetic disease of the connective tissue that produces defects in the fingernails, knee caps, and kidneys.

  Nail-patella syndrome is also known as Fong Dis- ease, Hereditary Onycho-Osteodysplasia (H.O.O.D.), Iliac Horn Disease, and Turner-Kieser syndrome. Patients who have nail-patella syndrome may show a variety of physical defects. The hallmark features of this syndrome are poorly developed fingernails, toenails, and patellae (kneecaps). Other common abnormalities include elbow deformities, abnormally shaped pelvis bone (hip bone), and kidney (renal) disease.

  Less common medical findings include defects of the upper lip, the roof of the mouth, and unusual skeletal abnormalities. Skeletal abnormalities may include poor- ly developed scapulae (shoulder blades), sideways bent fingers (clinodactyly), clubfoot, scoliosis, and unusual neck bones. There are also other effects, such as thick- ening of the basement membrane in the skin and of the tiny clusters of capillaries (glomeruli) in the kidney. Sci- entists have recognized an association between nail- patella syndrome and colon cancer. Nail-patella syn- drome is associated with open-angle glaucoma, which, if untreated, may lead to blindness. Patients may also have cataracts, drooping eyelids (ptosis), or corneal problems such as glaucoma.

  People with nail-patella syndrome may display only a few or many of the recognized signs of this disease. Symp- toms vary widely from person to person. Signs even vary within a single family with multiple affected members.

  The incidence of nail-patella syndrome is approxi- mately one in 50,000 births. This disorder affects males and females equally. It is found throughout the world and occurs in all ethnic groups. The strongest risk factor for nail-patella syndrome is a family history of the disease.

  Nail-patella syndrome has been recognized as an inherited disorder for over 100 years. It is caused by mutations in a gene known as LIM Homeobox Transcrip- tion Factor 1-Beta (LMX1B), located on the long arm of chromosome 9.

  The LMX1B gene codes for a protein that is impor- tant in organizing embryonic limb development. Muta- tions in this gene have been detected in many unrelated people with nail-patella syndrome. Scientists have also been able to interrupt this gene in mice to produce defects similar to those seen in human nail-patella syndrome.

  Nail-patella syndrome is inherited in an autosomal dominant manner. This means that possession of only one copy of the defective gene is enough to cause disease. When a parent has nail-patella syndrome each of their children has a 50% chance to inherit the disease-causing mutation. The most obvious sign associated with nail-patella syndrome is absent, poorly developed, or unusual finger- nails. Fingernail abnormalities are found in over 80% of patients with this disorder. Abnormalities may be found in one or more fingernails. Only rarely are all fingernails affected. This disease most commonly affects the finger- nails of the thumbs and index fingers. The pinky finger- nail is least likely to be affected. Fingernails may be small and concave with pitting, ridges, splits, and/or dis- coloration. Toenails are less often affected. The lunulae, or light-colored crescent moons, at the base of the finger- nail bed next to the cuticle are sometimes triangularly- shaped in people with nail-patella syndrome.

  A new mutation causing nail-patella syndrome can also occur, causing disease in a person with no family his- tory. This is called a sporadic occurrence and accounts for approximately 20% of cases of nail-patella syndrome. The children of a person with sporadic nail-patella syndrome are also at a 50% risk of developing signs of the disorder.

  Medical signs of nail-patella syndrome vary widely between patients. Some patients with this disorder do not display symptoms. These patients are discovered to have the nail-patella syndrome only when genetic studies trace their family history. Scientists are now working to learn what causes different people to display such different symptoms of nail-patella syndrome.

  

N

Nail-patella syndrome Definition

Causes and symptoms

Description

Diagnosis

  Kneecap abnormalities are the second most common sign associated with this disorder. Either or both kneecaps may be missing or poorly formed. If present, kneecaps are likely to be dislocated. The knees of people with nail-patella syndrome may have a square appear- ance. Besides the kneecap, other support structures including bones, ligaments, and tendons may also be malformed. These support structures stabilize the knee, therefore patients with some leg malformations may have difficulty in walking.

  Treatment is usually not necessary. Treatment, when required, depends on each patient’s specific symptoms. Severe kidney disease is treated with dialysis or a kidney transplant. Patients receiving kidney transplant do not devel- op nail-patella type renal complications in their new kidney.

  Nail-patella syndr ome

  the disease. Parents with this disease have a 50% chance of passing it to each of their children. As of 2001, current

  Genetic counseling is offered to persons who have

  clubfoot deformity. Manipulation or surgery may be required to correct hip dislocation. Cataracts are also sur- gically treated. Medical treatment at early signs of glau- coma prevents progression of the disease to blindness.

  Orthopedic surgery may be necessary for congenital

  A wheelchair may be required if walking becomes painful due to bone, tendon, ligament, or muscle defects.

  Prenatal diagnosis for nail-patella syndrome by third-trimester ultrasound was documented in 1998. Pre- natal diagnosis via genetic testing of cells obtained by chorionic villus sampling was reported the same year. As of 2001, prenatal genetic testing for nail-patella syn- drome is not yet widely available. There is controversy surrounding the use of prenatal testing for such a variable disorder. Prenatal testing cannot predict the extent of an individual’s disease.

  The hip bones of approximately 80% of patients with nail-patella syndrome have unusual bony projec- tions called posterior iliac horns. These bony projections, or spurs, are internal and not obvious unless they are detected on x ray. This unusual pelvic anatomy is not associated with any other disease.

  Diagnosis of this disease is most often made on visual medical clues such as the characteristic abnormali- ties of the fingernails and kneecaps. Diagnosis is con- firmed by x-ray images of the affected bones and, when indicated, kidney biopsy. The bony pelvic spurs found in 80% of patients with nail-patella syndrome are not associated with any other disease.

  As of early 2001, genetic testing for nail-patella syndrome is available only through research institutions that are working to further characterize this disorder. Genetic testing cannot predict which signs of the disease will develop. Nor can genetic testing predict the severity of disease symptoms. Improved genetic testing for nail- patella syndrome is anticipated in the future.

  Additionally, the irises of the eye may be multicolored, possibly displaying a clover-shaped pattern of color.

  astigmatism.

  Eye problems may be present and vary from person to person. Nail-patella syndrome is associated with open angle glaucoma. Open angle glaucoma is caused by fluid blocked into the front chamber of the eye. This blocked fluid builds increasing pressure into the eye. If untreated, this increased pressure may lead to permanent damage of the optic nerve and irreversible blindness. Some patients with nail-patella syndrome have ptosis, or drooping eye- lids. Nail-patella syndrome has also been associated with abnormalities of the cornea, cataracts, and

  Various skeletal symptoms may occur. Patients with nail-patella syndrome may not be able to fully straighten their arms at the elbow. This may create a webbed appear- ance at the elbow joint. Patients may have sideways bent fingers, poorly developed shoulder blades, clubfoot, hip dislocation, unusual neck bones, or scoliosis.

  Kidney disease is present in at least 30% of people with nail-patella syndrome. Biopsy shows lesions that resemble those of inflammation of the clusters of capil- laries in the kidneys ( glomerulonephritis), but without any infection present. Kidney failure is the most danger- ous consequence of nail-patella syndrome. It occurs in about 30% of patients who have kidney involvement. An early sign of kidney involvement is the presence of pro- tein or blood in the urine (chronic, benign proteinuria and hematuria.) Kidney involvement is progressive, so early diagnosis and treatment of renal disease is impor- tant. Kidney disease has been reported in children with nail-patella syndrome, but renal involvement more com- monly develops during adulthood.

Treatment

  Nail r

  infections in the area of the nail. There are nonsurgical as well as surgical methods of nail removal.

K E Y T E R M S

  emo Chorionic villus sampling (CVS)—A procedure used va Purpose l for prenatal diagnosis at 10–12 weeks gestation.

  Nails are removed only when necessary to allow the Under ultrasound guidance a needle is inserted skin beneath the nail (the nail bed) to heal or in some either through the mother’s vagina or abdominal wall cases, to remove a nail that has been partially pulled out and a sample of cells is collected from around the in an accident. In the case of toenails, it is occasionally early embryo. These cells are then tested for chromo- necessary to remove the nail of the large toe due to a some abnormalities or other genetic diseases. chronic condition caused by badly fitted shoes. In gener- Glomeruli—Tiny clusters of capillaries in the kidney. al, however, doctors prefer to try other forms of treatment Hematuria—The presence of blood in the urine. before removing the nail. Depending on the cause, nail Patella—The kneecap. disorders are usually treated with oral medications; applying medicated gels or creams directly to the skin

  Proteinuria—Excess protein in the urine.

  around the nail; avoiding substances that irritate the nail folds; surgical lancing of abscesses around the nail; or injecting corticosteroids under the nail fold. genetic testing technology cannot predict the severity or

  The most common causes of nail disorders include: scope of an individual’s symptoms.

• Trauma. The nails can be damaged by nail biting, using Because many possible manifestations of nail-patel- the fingernails as tools, and incorrect use of nail files la syndrome exist, patients are advised to pursue extra and manicure scissors as well as by accidents and medical care including regular urinalysis and special eye sports injuries.

  exams. Children with nail-patella syndrome should be

• Infections. These include fungal infections under the screened for scoliosis.

  nails, bacterial infections of cuts or breaks in the nail folds, or infections of the nails themselves caused by

Prognosis

  Candida albicans