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Flashcards in genetic basis of complex inheritance Deck (14):
1

what is penetrance?

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

2

what gene is responsible for patients manifesting cystic fibrosis?

CFTR

3

what are genetic modifiers?

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

4

what is uniparental disomy?

inheritance of a chromosome pair from one parental origin

5

what is genomic imprinting?

genes are expressed from only one chromosome (parent) e.g. if the gene from the father is imprinted it is silenced and only the allele inherited from the mother will be expressed

6

what is gynogenic uniparental diploidy?

2 maternal genomes

7

what is androgenic uniparental diploidy?

2 paternal genomes

8

where is mitochondrial DNA inherited from?

mother

9

how many more times likely is it that there will be a mutation in the mitochondrial DNA compared to the nuclear genome?

100 times more likely

10

why is the mitochondrial DNA more likely to mutate?

lack of efficient DNA repair system
lack of protective proteins, such as histones
damaged by reactive oxygen species, such as free radicals

11

what is homoplasmy?

uniform mitochondrial DNA

12

what is heteroplasmy?

two or more types of mitochondrial DNA?

13

when is disease likely to occur in heteroplasmy?

when there is a high percentage of mitochondrial mutation

14

what are the 3 myopathies that occur in mitochondrial disease?

myoclinic epilepsy with ragged red fibers (MERRF)
mitochondrial myopathy, encephalomyopathy, lactic acidosis, stroke like symptoms ( MELAS)
chronic progressive external opthalmoplegia (CPEO)