Flashcards in Gnetic basis of complex inheritance Deck (20):
1
Mendelian Inheritance (3)
Law of dominance
Law of segregation
Law of independent assortment
2
Non- mendelian inheritance
Does not fit in with Mendelian inheritance due to gene conversion and the ability of an intermediate phenotype
3
Anticipation
Eg triple repeat expansion
4
Extracellular inheritance
Eg mitochondrial DNA
5
Genomic printing
Variants from parents
6
Incomplete penetrance
Environmental factor
Genetic modifiers
7
Penetrance
Frequency with which trait is manifested by individuals carrying the gene
% with trait (mutant)/% with trait (wild) = RISK
8
Genetic modifiers
Genes that have small quantitative effects on level of expression of another gene - many involve polymorphism
9
Genomic imprinting
Genes expressed from only 1 chromosome so is parent of origin dependent and there is a higher risk of causing genetic disease
10
Epigenetic modifications
Heritable changes in gene function not explained by changes in DNA
11
Cytosine ( mC)
Induces structural adaption of chromosomal region so as to continue altered activity states
12
Anticipation - triple repeat
Disease presents at earlier age and/or increasing severity with age eg Huntingtons and myotonic dystrophy
13
Genetic mechanisms
Deletion, point mutation, imprinting error and uniparental disomy
14
Imprinting error (P)
Loss of maternal expression causing Angleman syndrome - epilepsy, awkward gait and retardation
15
Imprinting error (M)
Prader -wili syndrome - hypotonia short and obese
16
Uniparental disomy
Inheritance of a chromosome pair from one parental origin
17
Gyogenic
2 Maternal
Mass of embryo and ovarian teratoma
18
Androgenic
2 Paternal
Mass of placenta and Hydatidiform male
19
What does mitochondrial inheritance effect?
Tissue with high metabolic demand
20