The Genetic Basis of Complex Inheritance

Question 1

Mendelian Inheritance

Answer 1

The Law of Dominance
The Law of Segregation
The Law of Independent Assortment

Question 2

Non-Mendelian Inheritance

Answer 2

Does not fit in with Mendelian’s Law

Several variants in several genes acting together

Question 3

Pattern of Non-Mendelian Inheritance

Answer 3

Incomplete Penetrance
Genomic imprinting
Extranuclear Inheritance
Anticipation 
Complex

Question 4

Incomplete Penetrance

Answer 4

Environmental factor

Genetic Modifiers

Question 5

Genomic Imprinting

Answer 5

Variants from parents
Genes from only one chromosome is expressed
Dominance is meaningless

Question 6

Extranuclear Inheritance

Answer 6

Mitochondrial mutations

Question 7

Anticipation

Answer 7

Triplet repeat expansion

Question 8

Complex

Answer 8

Multi-genic risk

Question 9

Penetrance

Answer 9

the frequency with which a trait is manifested by individuals carrying the gene

Question 10

100% Penetrance

Answer 10

Cystic Fibrosis

Question 11

50% Penetrance

Answer 11

Ovarian Cancer

Question 12

Genetic Modifiers

Answer 12

Genes that have small quantitative effects on the level of expression of another gene

Question 13

Environmental Factors

Answer 13

Lifestyle, Diet, Smoke, Alcohol, Drugs, Stress, Air Pollution, Chemicals, Infection

Question 14

Epigenetic Modifications

Answer 14

Heritable changes in gene function that cannot be explained by changes in DNA sequence

Question 15

Methylation

Answer 15

Addition of a methyl group to DNA. Can change the activity of the DNA without changing the structure

Question 16

Uniparental Disomy

Answer 16

Inheritance of a chromosome pair from one parental origin and no copy from the other parent

Question 17

Gynogenic

Answer 17

2 maternal genomes
Mass of embryo
Ovarian teratoma

Question 18

Androgenic

Answer 18

2 Paternal genomes
Mass of placenta
Hydatidiform

Question 19

Human models of imprinting disorders

Answer 19

Angelman Syndrome

Prader-Willi Syndrome

Question 20

Angelman Syndrome (4)

Answer 20

Epilepsy
Mental retardation
Awkward Gait
Inappropriate laughter

Question 21

Prader-Willi Syndrome (4)

Answer 21

Hypotonia
Mental retardation
Short stature
Marked obesity

Question 22

Chromosomal region for AS and PWS

Answer 22

15q11-13

Question 23

Mitochondrial Inheritance

Answer 23

Maternal

Paternal is destroyed during fertilisation

Question 24

Heteroplasmy

Answer 24

Mitochondira that have a mutation in the mtDNA and some that do not

Question 25

Homoplasmy

Answer 25

Cell that has a uniform collection of mtDNA (either all normal mtDNA or completely mutant mtDNA)

Question 26

Mitochondrial Disease affects____

Answer 26

Tissues with high metabolic demand

Question 27

Mitochondrial Myopathies

Answer 27

MERRF, MELAS, CPEO, LHON, Leigh’s Syndrome, DAD

Question 28

Three parent baby

Answer 28

Healthy nuclear DnA removed from mother
Transported into donor egg with healthy mitochondrial DNA
Reconstructed egg fertilised with sperm and implanted

Question 29

Anticipation- Triplet Repeat Expansion

Answer 29

Disease presents at earlier age and/or increasing severity in succeeding generations

Question 30

Examples of triple repeat disease

Answer 30

Huntington’s disease
Myotonic dystrophy
Fragile X syndrome

Question 31

Multigenic/Complex Inheritance is often seen in

Answer 31

heart disease, breast cancer, autism

Question 32

Multigenic/Complex Inheritance consist of

Answer 32

Multiple low penetrance variants