Contents

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Chapter 1?Introduction  1

1.1¡¡Genetics 1

1.2¡¡Genetic Diseases 2

Summary 3

Exercises 3

Chapter 2?Mendel¡¯s Laws of Inheritance 6

2.1¡¡Gregor Mendel (1822-1884) 6

2.2?Mendel¡¯s Experiments on Pea Plants  6

2.3?Relative Knowledge About Mendel¡¯s Experiments 7

2.4?Mendel¡¯s Laws 11

Summary 11

Exercises 11

Chapter 3?The Bases of Genetics 12

3.1?Molecular Structure of a Gene 12

3.2?DNA Sequences 13

3.3?Regulation of Gene Expression 14

3.4?Genetic Imprinting 14

3.5?Mutation 14

3.6?Somatic and Germline Mutation 15

3.7?¡°Loss of Function Mutation¡± and ¡°Gain of Function Mutation¡± 15

3.8?Molecular Basis of Gene Mutation (Point Mutation) 15

3.9?Mutagens 16

Summary 17

Exercises 17

Chapter 4?Inheritance Pattern of Single Gene Disorders (Monogenic Inheritance) 20

4.1?Monogenic Inheritance (Mendelian) 20

4.2?Pedigree Chart 20

4.3?Autosomal Dominant Inheritance (AD) 21

4.4?Case Study 27

4.5?Comment 27

4.6?Autosomal Recessive Inheritance (AR) 28

4.7?Sex-linked Inheritance 29

Summary 34

Exercises 34

Chapter 5?Mitochondrial Disorders 39

5.1?Unusual Forms of Inheritance¡ªMatrilineal Inheritance 39

5.2?mtDNA 39

5.3?Mutation of Mitochondrial Gene 40

5.4?mtDNA Disorders 40

Summary 41

Exercises 41

Chapter 6?Polygenic or Multifactorial Inheritance 44

6.1?Polygenic Inheritance of Quantitative Traits 44

6.2?Characteristics of Polygenic Diseases 47

6.3?Polygenic Inheritance of Disease 47

6.4?Estimation of Recurrence Risks of Polygenic Diseases 48

Summary 50

Exercises 51

Chapter 7?Human Chromosomes 53

7.1¡¡Human Chromosomes 53

7.2?Structure of Chromosomes 54

7.3?Classification of Chromosomes 55

7.4?Chromosome Analysis 57

7.5?X chromatin and Lyon Hypothesis 58

7.6?Telomere and Cancer 60

Summary  60

Exercises 60

Chapter 8?Chromosomal Disorders 63

8.1?Disorders of Chromosome Number 63

8.2?Further Details 64

8.3?Karyotype Symbols 66

8.4?Numerical Abnormalities of Autosomes 69

8.5?Numerical Abnormalities of Sex Chromosomes 72

Summary  75

Exercises 76

Chapter 9?Biochemical Genetics 83

Biochemical Genetics  83

9.1?Molecular Diseases 83

9.2¡¡The Molecular Structures of Hemoglobin 84

9.3¡¡Globin Chain Structure 85

9.4¡¡Types of Globins Gene Mutations 86

9.5¡¡Common Hemoglobin Diseases 87

9.6?Thalassaemias 89

9.7?¦Â-Thalassaemia 90

9.8?¦Ä¦Â Thalassaemia 91

Summary 91

Biochemical Genetics 92

9.9¡¡Hereditary Enzymopathy/Inborn Errors of Metabolism (IEM) 92

9.10?Hereditary Enzymopathy 92

9.11¡¡Some Common Inborn Errors of Metabolism 94

Summary 98

Exercises 99

Chapter 10?Diagnosis of Genetic Diseases 100

10.1?Symptomatic Diagnosis 100

10.2¡¡Presymptomatic Diagnosis 102

10.3?Prenatal Diagnosis 102

10.4?Carrier Tests 105

10.5¡¡Genetic Counseling in Disputed Paternity 105

10.6¡¡Consanguineous Marriage and Genetic Counseling 105

10.7¡¡Adoption and Genetic Counseling 105

Summary 106

Exercises 106

Chapter 11?Treatment of Genetic Diseases 109

11.1?Prenatal treatment 109

11.2?Postnatal Treatment 109

11.3?The First Gene Therapy 112

Summary 113

Exercises 113

Overall Review of Medical Genetics 115

Model Test 123

Model Test Paper of Medical Genetias of Xingjiang Medical University 123

Standard Answer 127

Some of the Standard Answers of ¡°Overall Review of Medical Genetics¡± 133

Some of the Answers of the Model Test Paper of Medical Genetics of Xinjiang Medical University 133

Experimental Guidance of Medical Genetics 133

Section A?Preparation of Human Chromosome Spreads 135

Section B?Karyotype Analysis of Human G-banding Chromosomes 137

Section C?Pedigree Analysis 142

Section D?Analysis of Human Finger Print 144

Section E?Karyotye Analysis of Down¡¯s syndrome 148

References