Inheritance Patterns Flashcards Preview

MCM Test 1 > Inheritance Patterns > Flashcards

Flashcards in Inheritance Patterns Deck (14):
1

what is a silence mutation?

the change of one base pair that does not change amino acid sequence, but may have subtle epigenetic effects

2

what is a missense mutation?

changes amino acid sequence and can be deleterious

3

what is a nonsense mutation?

mutation that leads to a premature stop codon and a truncated protein product, considered deleterious

4

what is a frameshift mutation?

mutation caused by an insertion or deletion of 1-2 bps leading to either changes in AA sequence or unmasking a stop codon leading to a truncated product, always deleterious

5

what is a triple repeat expansion?

DNA polymerase slips and adds a repeat of 3 base pairs (often CAG) expansions increase from generation to generation and can be deleterious at a certain length

6

what is a genetic locus?

specific position or location on a chromosome

7

what is an allele?

one of the alternative versions of a DNA nucleotide sequence that may be at a given chromosomal locus

8

characterize autosomal dominant inheritance

males/females equally affected
males/females equally capable of transmission
heterozygous
50% prob of passing on
usually gain of function

9

characterize autosomal recessive inheritance

males/females equally affected
males/females equally capable of transmission
homozygous
25% prob of passing on
usually loss of function

10

characterize X linked dominant inheritance

males/females equally affected
less severe phenotype in females due to X-inactivation
pedigree would look like autosomal dom without male to male transmission

11

characterize X linked recessive inheritance

mostly males affected
all daughters of affected males are carriers
no male to male transmission

12

what is penetrance?

when a characteristic presents in a patient

13

what can lead to non-penetrance?

modifier genes

14

what is variable expressivity?

expressing different symptoms with the same syndrome