The Practical Guide to the Genetic Family History 2e

Robin L. Bennett has been a genetic counselor in the genetics clinic at the University of Washington Medical Center for over 20 years. She has proven and award-winning expertise in helping patients, families, and her colleagues at all levels deal with the multitude of practical, logistical, psychological, and diagnostic issues that are a day to day part of genetic counseling.

Illustrations and Tables xv Foreword xxi Preface xxiii 1. The Language of the Pedigree 1 1.1 Why Take Time to Record a Genetic Family History / 1 1.2 What Do Cranes Have to Do with Anything? / 2 1.3 The Pedigree Is a Cost-Effective Tool for Genetic Diagnosis and Risk Assessment for Many Diseases / 4 1.4 Just Do ItC/ 5 1.5 The Pedigree as a Diagnostic Tool / 5 1.6 Using the Pedigree to Decide on Testing Strategies and for Evaluating At-risk Relatives / 6 1.7 Using the Pedigree to Establish the Pattern of Inheritance and Calculate Risks / 6 1.8 A Pedigree Can Help Distinguish Genetic from Other Risk Factors / 6 1.9 A Pedigree Can Document Shared Environment and Shared Genetic Risk Factors / 8 1.10 A Pedigree Can Help Identify Medical Screening Needs for Healthy Individuals / 8 1.11 Taking a Family History Is aWay to Establish Client Rapport and Facilitate Patient Decision Making / 8 1.12 A Pedigree Can Be Used for Patient Medical Education / 9 1.13 Using a Pedigree to Explore a Patient's Understanding and to Clarify Misconceptions / 11 1.14 Other Family Diagrams: Genograms and Ecomaps / 11 1.15 The Continuing Evolution of the Pedigree in the Age of Genomic Medicine / 14 1.16 References / 16 2. Practical Inheritance 18 2.1 A Tribute(ary) to Mendel / 18 2.2 A Brief Genetics Primer / 19 2.3 Types of Mutations / 22 2.4 Single-Gene Disorders / 23 2.5 Multi-Allelic Inheritance / 23 2.6 Confounding Factors in Recognizing Patterns of Inheritance / 23 2.7 Recognizing Patterns of Inheritance / 25 2.8 Nontraditional Inheritance Patterns / 36 2.9 Other Factors to Consider / 43 2.10 Environmental Factors / 44 2.11 Summary / 44 2.12 References / 45 3. Getting to the Roots: Recording the Family Tree 48 3.1 Creating a Medical Pedigree: Getting Started / 48 3.2 Laying the Foundation-Pedigree Line Definitions / 51 3.3 Keeping Track of Who Is Who on the Pedigree / 52 3.4 How Many Generations Are Included in a Pedigree? / 53 3.5 The Basic Pedigree Symbols / 55 3.6 Yours, Mine, and Ours-The Blended Family / 55 3.7 Pedigree Symbols Related to Pregnancy and Reproduction / 59 3.8 Assisted Reproductive Technologies (ART) and Use of Donor Gametes / 59 3.9 Adoption / 59 3.10 Infertility and No Children by Choice / 60 3.11 Affected Status: Shading the Pedigree Symbols / 60 3.12 A & W / 61 3.13 "He Died of a Broken Heart"-Family Hearsay / 61 3.14 Family History Unknown / 61 3.15 Documenting Medical Examinations and Evaluations / 61 3.16 A Note on Genetic Testing / 64 3.17 The Healthy Person with an Abnormal Genetic Test Result: The Difference between a Presymptomatic or Asymptomatic Carrier and an Obligate Carrier / 64 3.18 Pedigree Etiquette / 65 3.19 Recording a Basic Pedigree: The Questions to Ask / 68 3.20 The Closing Questions / 77 3.21 The Family Photo Album / 77 3.22 What's Remarkable about an Unremarkable Family History? / 79 3.23 Confidentiality and Family History / 79 3.24 When Is a Genetic Family History Significant? / 80 3.25 The Ultimate Pedigree Challenge / 80 3.26 Summary / 81 3.27 References / 81 4. Directed Medical-Genetics Family History Questions: Separating the Trees from the Forest 83 4.1 The Approach: Look for the Rare but Remember the Ordinary / 83 4.2 Physical Birth Anomalies and Variants / 87 4.3 Deafness/Hearing Loss / 99 4.4 Vision Impairment / 107 4.5 Intellectual Disability / 113 4.6 Pervasive Developmental Disorders (PDD)/Autism Spectrum Disorder (Autism) / 120 4.7 Cerebral Palsy / 122 4.8 Neurological and Neuromuscular Disorders / 125 4.9 Seizures / 127 4.10 Stroke / 131 4.11 Dementia / 134 4.12 Mental Illness / 138 4.13 Disorders Involving the Cardiac System / 143 4.14 Chronic Respiratory Disease / 146 4.15 Renal Disease / 149 4.16 Skeletal Anomalies and Disorders of Short Stature / 152 4.17 Diabetes / 154 4.18 Multiple Miscarriages, and Male and Female Infertility / 158 4.19 Sudden Infant Death Syndrome (SIDS) / 168 4.20 Summary / 169 4.21 References / 169 5. Using a Pedigree to Recognize Individuals with an Increased Susceptibility to Cancer 177 5.1 Using Medical Family History to Identify Persons At Risk for an Inherited Cancer Syndrome / 177 5.2 Information to Record in a Cancer Family History / 193 5.3 Cancer Risk Assessment Requires Accurate Information on Cancer Diagnoses / 193 5.4 Young Age of Onset Is Typical of Inherited Cancer Syndromes / 196 5.5 Rare Cancers Can Be a Clue to an Inherited Cancer Syndrome / 197 5.6 Sex-limited, Sex-influenced, and Parent of Origin Effects (Parental Imprinting and Uniparental Disomy) / 197 5.7 Environmental and Occupational Risk Factors for Cancer / 198 5.8 Be Cautious in Assuming a Cancer Is Sporadic or a New Mutation if the Cancer Is Diagnosed at a Young Age or Is Uncommon / 200 5.9 Family Ancestry Is Important for Cancer Risk Assessment / 206 5.10 Consanguinity and Cancer Risk Assessment / 206 5.11 Cancer Worry: The Pedigree as a Psychosocial Tool / 208 5.12 Models for Predicting the Risk of Developing Cancer or the Probability of Testing Mutation-Positive for an Inherited Cancer Syndrome / 209 5.13 Summary / 211 5.14 References / 212 6. Medical Verification of Family History, and Resources for Patients to Record Their Genetic Family Histories 220 6.1 Validation of Family Medical Information Is a Necessity / 220 6.2 How to Approach Family Members / 222 6.3 The Privacy of a Person's Life / 222 6.4 Requesting Medical Documentation / 223 6.5 Shifts in Medical Terminology / 225 6.6 Empowering Your Patients with Tools for Recording Their Own Medical-Family Histories / 226 6.7 Software Programs for Recording Family Histories / 227 6.8 Resources from the Genealogical Gurus / 228 6.9 Summary / 228 6.10 References / 229 7. The Challenge of Family History and Adoption 230 7.1 The Problem Defined / 230 7.2 Evolving Adoption Laws / 231 7.3 Obtaining Medical Information from a Closed Adoption / 234 7.4 Genetic Testing of Children Being Placed for Adoption / 235 7.5 A Model Medical and Genetic Family History form for Adoptions / 236 7.6 Summary / 236 7.7 References / 237 8. Family History and Assisted Reproductive Technologies 239 8.1 Gamete Donation Allows Couples at High Risk for Genetic Disorders to Have Healthy Offspring / 239 8.2 Screening Gamete Donors for Inherited Disorders / 241 8.3 Intractyoplasmic Sperm Injection and Genetic Disease / 243 8.4 Representing Gamete Donation and Surrogacy on a Pedigree / 243 8.5 The Forgotten Family History: The Offspring of Donor-Conceived Pregnancies / 245 8.6 Summary / 245 8.7 References / 246 9. Genetic Counseling: Where to Turn, What to Expect, and the Pedigree as a Psychosocial Assessment and Counseling Tool 247 9.1 Genetic Conditions Have Distinguishing Aspects from Other Medical Conditions / 247 9.2 The Pedigree as a Tool in Psychosocial Assessment and Counseling / 251 9.3 The Process of Genetic Counseling / 253 9.4 What to Expect from a Genetics Consultation / 253 9.5 Genetic Counselors and Other Genetic Specialists / 255 9.6 Locating a Genetics Professional / 256 9.7 Summary / 256 9.8 References / 256 10. Pedigree Predicaments 259 10.1 The Truth / 259 10.2 Lessons from History / 261 10.3 The Researcher and Family Studies / 263 10.4 Pedigrees and Publications / 264 10.5 Pedigrees and the Electronic Medical Record / 267 10.6 Summary / 271 10.7 References / 272 Glossary 274 A.1. Handy Reference Tables of Pedigree Nomenclature 287 A.2. Sample Clinical Pedigree Form 290 A.3. Sample Genetic Screening Form for Familial Cancer Risk Assessment 292 A.4. Sample Adoption Medical-Family History Form 295 A.5. The Genetics Library 308 A.6. Genetics in Practice: Five Case Studies 313 A.7. List of Genetic Disorders, Gene Symbols and Names, and Patterns of Inheritance 327 Index 340