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Flashcards in Genetics II Deck (61):
1

Regarding the tri nucleotide repeat associated with Huntington's disease, it is a...

CAG repeat that occurs in the Exon

2

CAG repeat occurring in the Exon

Huntington's disease

3

What complex in the ETC (respiratory chain of the mitochondria) does NOT contain Mitochondrial DNA?

Complex 2

4

If a couple both expresses Achondroplasia, what is the chance their offspring will have the lethal form of the gene?

25%

*Both are Heterozygous

5

Amelogenesia imperfecta with mutation p.Trp153.
What does this indicate?

Stop Codon was Created

6

c200+IG>A

What kind of mutation is this?

Splicing mutation

7

If a woman is a carrier for sickle cell and her husband is not, what has happened if her son expresses the trait?

Maternal MII error

*MII will essentially double the error

8

The repeating CCG expansion of the 5' UTR found in Fragile X Syndrome have over _____ repeats in affected individuals.

When over this number, _______ causes promoter modification and the cessation of RNA production

200

Methylation

9

Autosomal Dominant disorders rarely have what mechanism of disease?

What are 3 mechanisms seen in Autosomal dominant diseases?

Loss of Function


Dominant negative, Gain of Function, Haploinsufficiency

10

Type 1 Osteogenesis imperfecta W/O Dentinogenesis is due to what molecular mechanism?

Haploinsufficiency

11

Type 1 Osteogenesis imperfecta WITH Dentinogenesis is due to what molecular mechanism?

Dominant Negative

12

Cystic Fibrosis has different mutations in the same gene giving the same clinical phenotype - what is this called?

Allelic heterogenicity

13

Different mutations in different genes resulting in the same clinical phenotype is called...

Locus heterogenicity

14

CGG repeat in the non-coding 5'UTR:

Fragile X

15

CAG repeat in the 1st exon:

Huntington Disease

16

GAA repeat in the intron:

Freidreich Ataxia

17

CTG repeat in the non-coding 3'UTR:

Myotonic Dystrophy

18

Fragile X:

CGG repeat in the non-coding 5'UTR

19

Huntington Disease:

CAG repeat in the 1st Exon

20

Freidreich Ataxia:

GAA repeat in the Intron

21

Myotonic Dystrophy:

CTG repeat in the non-coding 3'UTR

22

What is the inheritance pattern for Achondroplasia?

Autosomal Dominant

*Fibroblast Growth Factor Receptror 3

23

_____% of individuals affected with Achondroplasia are de novo mutations on the _______ chromosome

80

paternal

24

The majority of individuals affected with Achondroplasia have a ______ to ______ substitution at codon 380.

Glycine

Arginine

25

99% of Achondroplasia is a ___ to ____ transition (purine for purine

1% of Achondroplasia is a ___ to ____ transversion (purine to pyrimidine)

G to A

G to C

26

T/F
Mutations causing Achondroplasia can cause an alteration of restriction sites leading to shorter DNA fragments

T/F
Mutations causing Achondroplasia can lead to "gain of function" - new or enhanced function of the gene

True

True

27

How is Achondroplasia diagnosed?

PCR

28

Huntington's disease is what type?

Autosomal Dominant

29

The age of onset changing in a disease indicates what?

Anticipation

30

Differential inheritance from mother or father indicates what?

Imprinting

31

T/F
Huntington's exhibits both Anticipation and Imprinting:

True

32

If No band is visible in Fragile X testing, the male is either ______ or ______.

Premutation

Full mutation carrier

33

If someone has inherited a mutant allele but isn't expressing the phenotype, this may be an example of...

Penetrance (or non-penetrance)

***light switch

34

If someone has inherited a mutant allele and may express the trait to variable degrees (different severity), this is an example of...

Variable Expressivity

35

The increased severity and/or decreased age of onset of disease with successive generations is...

Anticipation

36

What reflects an increased number of repeats passed from generation to generation?

Anticipation

37

What is the differential modification and expression of alleles of genes depending on the Sex of the parent of origin?

(it matters who gives you what)

Imprinting

38

Prader-Willi and Angleman are best examples of what?

Imprinting

39

How many human genes have been discovered that show Imprinting expression?

31

40

Inheritance of 2 copies of a gene/chromosome from one parent is called what?

This has implications for what kind of disorders?

Uniparental Disomy

Recessive and Imprinted disorders

41

Fragile X testing, 60-200 copies is...

Premutation

42

Fragile X testing, over 230 copies is...

Full mutation carrier

43

A PCR test for Fragile X will only detect up to 100 copies, if someone has the mutation, what test will confirm?

Southern Blot

44

What type of genetics has a high mutation rate, limited proofreading/repair, and lack of protective histones?

Mitochondrial

45

Define MItochondrial Heteroplasmy:

Both wildtype and mutant mito DNA

46

What is the Threshold Effect of Mitochondrial DNA?

Certain min. number of mutant proteins must be present before Expression occurs

47

T/F
Mitotic Segregation occurs in Mitochondrial genetics

True

48

p.Gly17Arg

AA substitution

Missense

***point mutation

49

p.Gly17*

Stop Codon

Nonsense

* = stop

50

p.Leu6Hisfs*3

Frameshift mutation

either deletion or duplication has occurred, now there's a Stop codon

51

De Novo mutation on Mom's allele:

NOT Achondroplasia

52

Achondroplasia detected by:

PCR restriction detection

53

Achondroplasia AA consequence:

AA lethal

54

c.101-2A>T

Splicing

55

T/F
Penetrance is binary

True

Either are or aren't penetrant

56

T/F
Variable expressivity is a function of penetrance

True

57

What needs to occur for Uniparental Disomy to take effect?

Must kick out other paren't chromosome

*otherwise trisomy

58

Mitochondrial Heteroplasmy =

wildtype and mutant DNA

59

T/F
Mitochondrial DNA has bigger mutation rate because no histones, no proofreading, and is at a site of radical oxidative formation

True

60

Beginning with a single DNA strand, how many cycles of PCR = 1 million copies

20

61

If a woman has 2 populations of mitochondrial DNA, one of which contains a mutation, this is an example of...

Heteroplasmy

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