Genetics II

Question 1

Regarding the tri nucleotide repeat associated with Huntington’s disease, it is a…

Answer 1

CAG repeat that occurs in the Exon

Question 2

CAG repeat occurring in the Exon

Answer 2

Huntington’s disease

Question 3

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

Answer 3

Complex 2

Question 4

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

Answer 4

25%

*Both are Heterozygous

Question 5

Amelogenesia imperfecta with mutation p.Trp153.

What does this indicate?

Answer 5

Stop Codon was Created

Question 6

c200+IG>A

What kind of mutation is this?

Answer 6

Splicing mutation

Question 7

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

Answer 7

Maternal MII error

*MII will essentially double the error

Question 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

Answer 8

200

Methylation

Question 9

Autosomal Dominant disorders rarely have what mechanism of disease?

What are 3 mechanisms seen in Autosomal dominant diseases?

Answer 9

Loss of Function

Dominant negative, Gain of Function, Haploinsufficiency

Question 10

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

Answer 10

Haploinsufficiency

Question 11

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

Answer 11

Dominant Negative

Question 12

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

Answer 12

Allelic heterogenicity

Question 13

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

Answer 13

Locus heterogenicity

Question 14

CGG repeat in the non-coding 5’UTR:

Answer 14

Fragile X

Question 15

CAG repeat in the 1st exon:

Answer 15

Huntington Disease

Question 16

GAA repeat in the intron:

Answer 16

Freidreich Ataxia

Question 17

CTG repeat in the non-coding 3’UTR:

Answer 17

Myotonic Dystrophy

Question 18

Fragile X:

Answer 18

CGG repeat in the non-coding 5’UTR

Question 19

Huntington Disease:

Answer 19

CAG repeat in the 1st Exon

Question 20

Freidreich Ataxia:

Answer 20

GAA repeat in the Intron

Question 21

Myotonic Dystrophy:

Answer 21

CTG repeat in the non-coding 3’UTR

Question 22

What is the inheritance pattern for Achondroplasia?

Answer 22

Autosomal Dominant

*Fibroblast Growth Factor Receptror 3

Question 23

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

Answer 23

80

paternal

Question 24

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

Answer 24

Glycine

Arginine

Question 25

99% of Achondroplasia is a ___ to ____ transition (purine for purine 1% of Achondroplasia is a ___ to ____ transversion (purine to pyrimidine)

Answer 25

G to A G to C

Question 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

Answer 26

True True

Question 27

How is Achondroplasia diagnosed?

Answer 27

PCR

Question 28

Huntington's disease is what type?

Answer 28

Autosomal Dominant

Question 29

The age of onset changing in a disease indicates what?

Answer 29

Anticipation

Question 30

Differential inheritance from mother or father indicates what?

Answer 30

Imprinting

Question 31

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

Answer 31

True

Question 32

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

Answer 32

Premutation Full mutation carrier

Question 33

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

Answer 33

Penetrance (or non-penetrance) ***light switch

Question 34

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

Answer 34

Variable Expressivity

Question 35

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

Answer 35

Anticipation

Question 36

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

Answer 36

Anticipation

Question 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)

Answer 37

Imprinting

Question 38

Prader-Willi and Angleman are best examples of what?

Answer 38

Imprinting

Question 39

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

Answer 39

31

Question 40

Inheritance of 2 copies of a gene/chromosome from one parent is called what? This has implications for what kind of disorders?

Answer 40

Uniparental Disomy Recessive and Imprinted disorders

Question 41

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

Answer 41

Premutation

Question 42

Fragile X testing, over 230 copies is...

Answer 42

Full mutation carrier

Question 43

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

Answer 43

Southern Blot

Question 44

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

Answer 44

Mitochondrial

Question 45

Define MItochondrial Heteroplasmy:

Answer 45

Both wildtype and mutant mito DNA

Question 46

What is the Threshold Effect of Mitochondrial DNA?

Answer 46

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

Question 47

T/F | Mitotic Segregation occurs in Mitochondrial genetics

Answer 47

True

Question 48

p.Gly17Arg

Answer 48

AA substitution Missense ***point mutation

Question 49

p.Gly17*

Answer 49

Stop Codon Nonsense * = stop

Question 50

p.Leu6Hisfs*3

Answer 50

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

Question 51

De Novo mutation on Mom's allele:

Answer 51

NOT Achondroplasia

Question 52

Achondroplasia detected by:

Answer 52

PCR restriction detection

Question 53

Achondroplasia AA consequence:

Answer 53

AA lethal

Question 54

c.101-2A>T

Answer 54

Splicing

Question 55

T/F | Penetrance is binary

Answer 55

True Either are or aren't penetrant

Question 56

T/F | Variable expressivity is a function of penetrance

Answer 56

True

Question 57

What needs to occur for Uniparental Disomy to take effect?

Answer 57

Must kick out other paren't chromosome *otherwise trisomy

Question 58

Mitochondrial Heteroplasmy =

Answer 58

wildtype and mutant DNA

Question 59

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

Answer 59

True

Question 60

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

Answer 60

20

Question 61

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

Answer 61

Heteroplasmy