9781422280393

LivingWith Diseases and Disorders

Muscular Dystrophy and Other Neuromuscular Disorders

Molly Jones S e r i e s A d v i s o r

Heather L. Pelletier, Ph.D. Pediatric Psychologist, Hasbro Children’s Hospital Clinical Assistant Professor, Warren Alpert Medical School of Brown University

LivingWith Diseases and Disorders Muscular Dystrophy and Other Neuromuscular Disorders

Living with Diseases and Disorders

ADHD and Other Behavior Disorders

Allergies and Other Immune System Disorders

Asthma, Cystic Fibrosis, and Other Respiratory Disorders

Autism and Other Developmental Disorders

Cancer and Sickle Cell Disease

Cerebral Palsy and Other Traumatic Brain Injuries

Crohn’s Disease and Other Digestive Disorders

Depression, Anxiety, and Bipolar Disorders

Diabetes and Other Endocrine Disorders

Migraines and Seizures

Muscular Dystrophy and Other Neuromuscular Disorders

LivingWith Diseases and Disorders

Muscular Dystrophy and Other Neuromuscular Disorders

Molly Jones

S e r i e s A d v i s o r Heather L. Pelletier, Ph.D. Pediatric Psychologist, Hasbro Children’s Hospital Clinical Assistant Professor, Warren Alpert Medical School of Brown University

Mason Crest

Mason Crest 450 Parkway Drive, Suite D Broomall, PA 19008 www.masoncrest.com

© 2018 by Mason Crest, an imprint of National Highlights, Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, taping, or any information storage and retrieval system, without permission from the publisher. MTM Publishing, Inc. 435 West 23rd Street, #8C New York, NY 10011

www.mtmpublishing.com President: Valerie Tomaselli Vice President, Book Development: Hilary Poole Designer: Annemarie Redmond

Copyeditor: Peter Jaskowiak Editorial Assistant: Leigh Eron Series ISBN: 978-1-4222-3747-2

Hardback ISBN: 978-1-4222-3758-8 E-Book ISBN: 978-1-4222-8039-3 Library of Congress Cataloging-in-Publication Data Names: Jones, Molly, 1933– author.

Title: Muscular dystrophy and other neuromuscular disorders / by Molly Jones; series    consultant, Heather Pelletier, PhD Hasbro Children’s Hospital, Alpert Medical School/    Brown University. Description: Broomall, PA: Mason Crest, [2018] | Series: Living with diseases and disorders |    Audience: Age 12+ | Audience: Grade 7 to 8. | Includes index. Identifiers: LCCN 2017000437 (print) | LCCN 2017002184 (ebook) | ISBN 9781422237588    (hardback: alk. paper) | ISBN 9781422280393 (ebook) Subjects: LCSH: Muscular dystrophy—Juvenile literature. | Neuromuscular diseases—    Juvenile literature. Classification: LCC RC935.M7 J66 2018 (print) | LCC RC935.M7 (ebook) | DDC 616.7/48—dc23

LC record available at https://lccn.loc.gov/2017000437 Printed and bound in the United States of America. First printing 9 8 7 6 5 4 3 2 1 QR CODES AND LINKS TO THIRD PARTY CONTENT

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Table of Contents Series Introduction . . . . . . . . . . . . . . . . . . . . . . 6 Chapter One: What Is a Neuromuscular Disorder? . . . . . . . . 9 Chapter Two: Neuromuscular Disorders and Daily Life . . . . . . 25 Chapter Three: Looking to the Future . . . . . . . . . . . . . 33 Chapter Four: Meeting the Challenges of NMDs . . . . . . . . . 45 Further Reading . . . . . . . . . . . . . . . . . . . . . . . 57 Series Glossary . . . . . . . . . . . . . . . . . . . . . . . 58 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 About the Advisor . . . . . . . . . . . . . . . . . . . . . . 64 About the Author . . . . . . . . . . . . . . . . . . . . . . 64 Photo Credits . . . . . . . . . . . . . . . . . . . . . . . . 64 Words to Understand: These words with their easy-to-understand definitions will increase the reader’s understanding of the text, while building vocabulary skills. Sidebars: This boxed material within the main text allows readers to build knowledge, gain insights, explore possibilities, and broaden their perspectives by weaving together additional information to provide realistic and holistic perspectives. Educational Videos: Readers can view videos by scanning our QR codes, which will provide them with additional educational content to supplement the text. Examples include news coverage, moments in history, speeches, iconic sports moments, and much more. Text-Dependent Questions: These questions send the reader back to the text for more careful attention to the evidence presented there. Research Projects: Readers are pointed toward areas of further inquiry connected to each chapter. Suggestions are provided for projects that encourage deeper research and analysis. Series Glossary of Key Terms: This back-of-the-book glossary contains terminology used throughout the series. Words found here increase the reader’s ability to read and comprehend higher-level books and articles in this field.

Key Icons to Look for:

SERIES Introduction A ccording to the Chronic Disease Center at the Centers for Disease Control and Prevention, over 100 million Americans suffer from a chronic illness or medical condition. In other words, they have a health problem that lasts three months or more, affects their ability to perform normal activities, and requires frequent medical care and/or hospitalizations. Epidemiological studies suggest that between 15 and 18 million of those with chronic illness or medical conditions are children and adolescents. That’s roughly one out of every four children in the United States. These young people must exert more time and energy to complete the tasks their peers do with minimal thought. For example, kids with Crohn’s disease, ulcerative colitis, or other digestive issues have to plan meals and snacks carefully, to make sure they are not eating food that could irritate their stomachs or cause pain and discomfort. People with cerebral palsy, muscular dystrophy, or other physical limitations associated with a medical condition may need help getting dressed, using the bathroom, or joining an activity in gym class. Those with cystic fibrosis, asthma, or epilepsy may have to avoid certain activities or environments altogether. ADHD and other behavior disorders require the individual to work harder to sustain the level of attention and focus necessary to keep up in school. Living with a chronic illness or medical condition is not easy. Identifying a diagnosis and adjusting to the initial shock is only the beginning of a long journey. Medications, follow-up appointments and procedures, missed school or work, adjusting to treatment regimens, coping with uncertainty, and readjusting expectations are all hurdles one has to overcome in learning how to live one’s best life. Naturally, feelings of sadness or anxiety may set in while learning how to make it all work. This is especially true for young people, who may reach a point in their medical journey when they have to rethink some of their original goals and life plans to better match their health reality. Chances are, you know people who live this reality on a regular basis. It is important to remember that those affected by chronic illness are family members,

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neighbors, friends, or maybe even our own doctors. They are likely navigating the demands of the day a little differently, as they balance the specific accommodations necessary to manage their illness. But they have the same desire to be productive and included as those who are fortunate not to have a chronic illness. This set provides valuable information about the most common childhood chronic illnesses, in language that is engaging and easy for students to grasp. Each chapter highlights important vocabulary words and offers text-dependent questions to help assess comprehension. Meanwhile, educational videos (available by scanning QR codes) and research projects help connect the text to the outside world. Our mission with this set is twofold. First, the volumes provide a go-to source for information about chronic illness for young people who are living with particular conditions. Each volume in this set strives to provide reliable medical information and practical advice for living day-to-day with various challenges. Second, we hope these volumes will also help kids without chronic illness better understand and appreciate how people with health challenges live. After all, if one in four young people is managing a health condition, it’s safe to assume that the majority of our youth already know someone with a chronic illness, whether they realize it or not. With the growing presence of social media, bullying is easier than ever before. It’s vital that young people take a moment to stop and think about how they are more similar to kids with health challenges than they are different. Poor understanding and low tolerance for individual differences are often the platforms for bullying and noninclusive behavior, both in person and online. Living with Diseases and Disorders strives to close the gap of misunderstanding. The ultimate solution to the bullying problem is surely an increase in empathy. We hope these books will help readers better understand and appreciate not only the daily struggles of people living with chronic conditions, but their triumphs as well.

—Heather Pelletier, Ph.D. Hasbro Children’s Hospital Warren Alpert Medical School of Brown University

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Words to Understand

biopsy: the removal and laboratory study of a small piece of living tissue. carrier: a person who does not experience a disease but can pass it on to offspring. chromosome: a threadlike structure found in the nucleus of most living cells, carrying genetic information in the form of genes. Duchenne muscular dystrophy: a type of muscular dystrophy that occurs usually in males. dystrophin: a protein essential for growing healthy muscles involuntary muscle: a muscle that functions without conscious direction.

muscle wasting: the loss of muscle tissue. mutation: a change to the structure of a gene.

neuromuscular: related to the nerve–muscle connection. neurophysiology: related to the functions of the nervous system and its connections with the physical body. voluntary muscle: a muscle that a person can move at will.

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Chapter One

What Is a Neuromuscular Disorder? D an is a busy young man. He operates an upbeat website and blog, sharing his life with others and encouraging others to live their own lives fully. He drives a wheelchair-accessible truck, lives and travels independently, and plays professional wheelchair tennis. Dan was diagnosed at age 13 with a form of muscular dystrophy (MD). Since then, he has found ways of doing as many of the things he has wanted to do in life as possible, in spite of his challenging diagnosis. You can find out more about Dan and his busy life at musculardystrophybook.com. Before Dan’s diagnosis, his life was very different. He didn’t think much about whether he’d be able to move his fingers to button his shirt. He wasn’t worried about keeping his shoulders, head, or feet from moving when he wanted them to be still. And playing tennis and basketball were not problems for him, either. One day, however, his life began to change, as his muscles began to grow weaker and harder to control.

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Muscular Dystrophy and Other Neuromuscular Disorders

Roughly 1 in 35,000 boys has some form of MD.

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What Is a Neuromuscular Disorder?

People like Dan have neuromuscular disorders (NMDs), and daily tasks and activities may at times be a struggle for them. If you or someone you know is in that situation, learning as much as possible about the particular type of disorder will help you find the best ways to approach life’s challenges. It will help you to understand what’s going on in the affected parts of the body, what has caused this change, and what the future holds. Neuromuscular disorders include a wide range of conditions in which nerves fail to give correct signals to one or more of the body’s muscle groups. Dozens of different neuromuscular disorders have been recognized and described by medical researchers. Each one causes its own pattern of movement problems because of the nerves and muscles involved. Of these disorders, muscular dystrophy (MD) occurs most often. Muscular dystrophy itself is an umbrella term for more than thirty distinct genetic diseases. Of these, the most common type is Duchenne muscular dystrophy (DMD). All neuromuscular disorders, even DMD, are rare conditions. Approximately 1 out of every 35,000 boys born worldwide will have some type of MD. The conditions occur even less frequently for girls, who very rarely acquire DMD. However, girls are subject to other types of NMDs. Each type of neuromuscular disease, including MD, is a genetic disease caused by a gene mutation . NMDs are not contagious, so a person with MD cannot transmit the disorder to another person—except from a parent to a child through the parent’s genes. Genetics and MD The muscle problems that come with muscular dystrophy are caused by an accidental, random event called a mutation, which changes the functioning of a gene that controls that particular muscle or muscle group. The mutation disrupts the way the gene normally sends signals to the muscle. This damage can occur

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Muscular Dystrophy and Other Neuromuscular Disorders

Genes and How You Became You Human beings inherit traits, such as height, hair color, eye color, and the shape of facial features, from their parents. These traits are determined at the time of conception, when a sperm cell is united with an egg cell, creating a new human being. Information about these traits is carried in genes. Some traits are determined by a single pair of genes, one from each parent; other, more complex, traits involve many genes. Every cell in the body contains a nucleus, and within each nucleus are 46 microscopic, threadlike chromosomes , 23 from each parent. These 23 pairs of chromosomes carry the genes inherited from each parent. Each pair of chromosomes carries tens of thousands of paired genes. Traits resulting from all but one of these 23 pairs of chromosomes are unrelated to whether they came from the male or female parent. In that one pair of chromosomes, called the X and Y chromosomes, the source may matter. For example, the gene that determines whether a child will be male or female is found on the male chromosome of that 23rd pair. The male parent has one X - chromosome and one Y - chromosome. The female parent has two X-chromosomes. Therefore a female will always pass on a gene from an X chromosome, but the male will pass on genes from his X chromosome about half the time, and from his Y chromosome about half the time. If the male passes on a gene from the Y-chromosome, the child will then have one X and one Y gene, and will therefore be male. If the male passes on a gene from the X-chromosome, the child will have two X genes, one from each parent, and will therefore be female.

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What Is a Neuromuscular Disorder?

The muscular system.

in more than one way. For example, the person may have inherited an already damaged gene from a parent. Or the damage could have occurred from a gene mutation at the time of conception. Either way, the damage leaves the gene and the muscles it was intended to control unable to function as originally intended. Muscles are primarily made of proteins. The protein produced by the dystrophin gene is essential for growing healthy muscle tissue. When a gene associated with producing healthy dystrophin is damaged, the damage causes some muscle protein to be missing or incorrectly formed. This affects the health and strength of the muscle. Since the dystrophin gene sends signals to the muscle, a mutation on the dystrophin gene can result in a type of MD. This loss and weakening of muscle tissue will continue to get worse over time, and, unfortunately, the resulting disability will also grow worse.

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Muscular Dystrophy and Other Neuromuscular Disorders

Duchenne muscular dystrophy (DMD) is caused by a mutation on a gene from the X chromosome inherited from the female parent. With two X chromosomes, a healthy female child will have a pair of healthy X-related dystrophin genes. If a female child has one damaged dystrophin gene, her healthy second dystrophin gene is usually able to overcome effects from the damaged gene. She will become a carrier of MD, but won’t experience the disease fully. But a male child with one damaged dystrophin gene doesn’t have the advantage of a second X-related dystrophin gene. He will experience the full effects of MD. Types of MD The effects on people who have various types of MD vary widely, depending on which gene is damaged and which muscles they involve. Below are descriptions of several of the many types of MD. • Duchenne muscular dystrophy (DMD) symptoms include general muscle weakness and muscle wasting , or a loss of muscle mass and strength. DMD eventually involves all voluntary muscles, most especially the pelvis and the arms and legs. Usually cases of DMD are recognized by the time kids are about five years old, but sometimes DMD isn’t diagnosed until kids reach school age. By that time, their posture and way of walking will begin to show the typical MD characteristics. These include a tendency to walk on the toes or forward part of the feet, a waddling gait (a side-to- side rocking motion that helps maintain balance), enlarged calf muscles, clumsiness and frequent falls, and difficulty raising the arms. Children with DMD frequently require a wheelchair by the time they are between ages 7 and 12. Eventually, DMD can cause weakened heart muscles and respiratory (breathing) complications, both of which contribute to a shortened life span. It is unusual for a person with DMD to survive beyond their 30s, but in some cases they do.

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