GENETICS (transition)

Question 1

codon redundancy definition

Answer 1

when different base pair codons can make the same amino acid

aka non missense

Question 2

single base mutation not change the protein sequence

Answer 2

bc of redundancy in the codon

Question 3

first step in central dogma

Answer 3

transcription

Question 4

second and third steps in central dogma after transcription

Answer 4

splicing

translation

Question 5

why might someone have a mutation for a gene their parent has, but not have the condition themselves

Answer 5

the mutation has variable penetrance

Question 6

why is NGS (next generation sequencing) better over conventional sequencing

Answer 6

allows sequencing of larger number of genes

Question 7

what type of chromosome translocation does aCGH pick up

Answer 7

UNbalanced chromosome abnormalities only eg deletions and duplications (not balanced ones eg translocations)

Question 8

why is aCGH better than karyotyping

Answer 8

higher resolution

Question 9

if a mutation (base change) for neurofibromatosis is in 5% of the population, how is it classified;

definitely benign 
probs benign 
of uncertain significance
probs pathogenic   
definitely pathogenic

Answer 9

definitely benign

Question 10

what characteristic of cancer cells allows them to develop new characteristics

Answer 10

genomic instability

Question 11

missense definition

Answer 11

a change in 1 base that causes a change in amino acid = change in protein

Question 12

if aCGH picks up unbalanced chromosome translocations, what do you use to pick up balanced chromosome translocations

Answer 12

FISH

Question 13

central dogma definition

Answer 13

the explanation of how genetic material flows

Question 14

penetrance definition

Answer 14

likelihood of having disease if you have the mutation

Question 15

what does 100% penetrance mean

Answer 15

if you have the mutation you will get the condition

Question 16

what does variable expression mean

Answer 16

people with a condition can be affected to varying degrees

Question 17

which part of the genome contains genetic material (exon or intron)

what process removes the other part

Answer 17

exon

splicing

Question 18

what is a start codon called

Answer 18

promotor

Question 19

is a premature stop codon pathogenic or benign

Answer 19

pathogenic

Question 20

what type of mutation does a base insertion/deletion cause

is this pathogenic or benign

Answer 20

frameshift mutation

bad ! bc all amino acids change after this point = pathogenic

Question 21

what is a polymorphism

Answer 21

variant that doesnt cause disease

Question 22

if there is a mutation in an intron what does this mean

pathogenic or benign

Answer 22

benign bc introns are gotten rid of anyway

Question 23

what is a de novo mutation

Answer 23

acquired during fertilization

both parents don’t have mutation or disease

Question 24

does chromosome analysis pick up balanced or unbalanced translocations

Answer 24

balanced (technically both, but if youre looking for unbalanced just do aCGH)

Question 25

which type of genetics testing is done most (ie best guess in exams)

Answer 25

aCGH

Question 26

what is NGS (next generation sequencing) used to see

Answer 26

point mutations

Question 27

is NGS expensive or cheap

why

Answer 27

expensive

large number of base pairs done

Question 28

when would you use PCR over NGS for point mutations

Answer 28

if no family history - so you dont know which mutation it is that youre looking for, just looking for A mutation

Question 29

what is a mendelian disorder in terms of penetrance and incidence

Answer 29

high penetrance - little environmental factors

low incidence

Question 30

autosomal dominant

risk of affected child if affected parent

Answer 30

1 in 2

Question 31

inheritance pattern of most cardiac congenital conditions eg long QT

Answer 31

autosomal dominant

Question 32

autosomal recessive

risk of affected child if both parents carriers

Answer 32

1 in 4

Question 33

what generational pattern occurs with autosomal recessive conditions

Answer 33

tends to skip generations

Question 34

x linked recessive inheritance

how many copies of gene do males need to have condition
how many copies of gene do females need to have condition

Answer 34

males - 1

females - 2 (can be carriers)

Question 35

x linked dominant inheritance

what happens to the children (give male and female example) of an affected male

Answer 35

male child - unaffected (gets Y from father)

female child - affected bc dominant

Question 36

in mitochondrial inheritance is it every child of an affected FEMALE or MALE that will be affected

why

Answer 36

every child of an affected female

mitochondrial DNA = defects come from mother

Question 37

what does Y linked conditions cause in males

Answer 37

infertility

Question 38

by what mechanism does x inactivation happen

Answer 38

methylation

Question 39

are dizygotic twins identical or non identical

how much of their genes do they share

Answer 39

non identical

50%

Question 40

are monozygotic twins identical or non identical

how much of their genes do they share

Answer 40

identical (mono = 1 egg)

100%

Question 41

which type of twins (monozygotic or dizygotic) are used to prove if something is purely genetic or has environmental factors

Answer 41

monozygotic

Question 42

after clinical trials what review do new drugs need to go through

Answer 42

FDA review

Question 43

genetic anticipation definition

Answer 43

when each generation develops a genetic disease at an earlier age

Question 44

hereditability definition

Answer 44

proportion of observable differences in a trait between individuals in a population that is due to genetic differences

Question 45

reasons why someone may be the first in family to present with an autosomal dominant condition (2)

Answer 45

de novo mutation

low penetrance - other people have gene just don’t have condition