Gnetic basis of complex inheritance Flashcards Preview

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Flashcards in Gnetic basis of complex inheritance Deck (20)
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1
Q

Mendelian Inheritance (3)

A

Law of dominance
Law of segregation
Law of independent assortment

2
Q

Non- mendelian inheritance

A

Does not fit in with Mendelian inheritance due to gene conversion and the ability of an intermediate phenotype

3
Q

Anticipation

A

Eg triple repeat expansion

4
Q

Extracellular inheritance

A

Eg mitochondrial DNA

5
Q

Genomic printing

A

Variants from parents

6
Q

Incomplete penetrance

A

Environmental factor

Genetic modifiers

7
Q

Penetrance

A

Frequency with which trait is manifested by individuals carrying the gene
% with trait (mutant)/% with trait (wild) = RISK

8
Q

Genetic modifiers

A

Genes that have small quantitative effects on level of expression of another gene - many involve polymorphism

9
Q

Genomic imprinting

A

Genes expressed from only 1 chromosome so is parent of origin dependent and there is a higher risk of causing genetic disease

10
Q

Epigenetic modifications

A

Heritable changes in gene function not explained by changes in DNA

11
Q

Cytosine ( mC)

A

Induces structural adaption of chromosomal region so as to continue altered activity states

12
Q

Anticipation - triple repeat

A

Disease presents at earlier age and/or increasing severity with age eg Huntingtons and myotonic dystrophy

13
Q

Genetic mechanisms

A

Deletion, point mutation, imprinting error and uniparental disomy

14
Q

Imprinting error (P)

A

Loss of maternal expression causing Angleman syndrome - epilepsy, awkward gait and retardation

15
Q

Imprinting error (M)

A

Prader -wili syndrome - hypotonia short and obese

16
Q

Uniparental disomy

A

Inheritance of a chromosome pair from one parental origin

17
Q

Gyogenic

A

2 Maternal

Mass of embryo and ovarian teratoma

18
Q

Androgenic

A

2 Paternal

Mass of placenta and Hydatidiform male

19
Q

What does mitochondrial inheritance effect?

A

Tissue with high metabolic demand

20
Q

Does mitochondrial DNA have a higher or lower mutation rate than nuclear DNA?

A

Higher - 100 fold more
Lack of DNA repair system and protective histones
Oxygen release radicals that attack DNA (mtDNA)