Genetics

Question 1

When do chromatids attach to spindle

Answer 1

Metaphase

Question 2

Pyrimidine DNA bases

Answer 2

CUT
Cytosine, uracil, thymine

Question 3

Nucleotide base pairs

Answer 3

AT Gold Coast
Adenosine-thymine

Guanine-cytosine

Question 4

Direction of leading strand DNA replication and transcription

Answer 4

5’ to 3’

Question 5

Features that protect mRNA - convert pre-mRNA to mature mRNA

Answer 5

Add Poly A tail
5’ Cap

Question 6

Function of MiRNA

Answer 6

Function post transcription

Question 7

Type of mutation susceptible to anticipatin

Answer 7

Repeat Expansion
- Huntingotn’s - CAG
- Myotonic dystrophy

Question 8

Duchennes muscular dystrophy - cause of genetic defect

Answer 8

Exon deletion

Question 9

Inheritance of DMD

Answer 9

X linked

Question 10

What stage of cell cycle does base excision repair occur

Answer 10

G1

Question 11

Mismatch repair - genes and proteins pairs involved

Answer 11

MutS - MLH1 and PMS2

MutL - MSH2 and MSH6

Question 12

Homologous repair - what stage of cell cycle can it occur?

Answer 12

Has to occur in S or G2 –> needs identical chromatid as template (after replication)

Question 13

Robertsonian translocation
- What is it?
- Which chromsomes are susceptible

Answer 13

Combination of acrocentric chromsomes with short p arms, when they fuse lose their p arms

Chromsomes 13,14,15, 21, 22

Can cause Down, Patau’s etc

Question 14

Best method to detect balanced chromsome translocations

Answer 14

Karyotyping

Question 15

Karyotyping - when is cell arrested

Answer 15

Metaphase using colchicine

Question 16

Method that picks up copy number variations

Answer 16

Comprative genome hybridisation

Question 17

Method that picks up translocation products (e.g BRC-ABL)

Answer 17

FISH

Question 18

Sanger vs Next generations sequencing

Answer 18

Sanger - looks at nucleotide sequence, need to know what you’re targetting

Next generation sequencing - nonselective, targets whole genome, but doesn’t pick up large chromsomal changes

Question 19

Same gene location, different mutations (allele), same disease

Answer 19

Allelic heterogeneity

E.g CF, MEN

Question 20

Different genese, same disease

Answer 20

Locus (non-allelic) heterogeneity

E.G retinitis pigemntosum

Question 21

Locus homogeneity = phenotypic heterogeneity

Answer 21

Same gene location, different mutations, different diseases

E.G DMD

Question 22

Uneven distribution of allele frequency when forming gametes during meiosis, so unequal frequencies of alleles on gamates

Answer 22

Linkage disequilibrium

Question 23

Barr body

Answer 23

Randomly selected X chromsome that gets inactivated (lyonisation)

Question 24

Prader willi imprinting

Answer 24

Maternal

Question 25

Angelman imprinting

Answer 25

Paternal

Question 26

Two alleles expressed independantly in heterozygote

Answer 26

Co-dominance

Question 27

X linked adrenoleukodystrophy - most likely sign

Answer 27

Peripheral neuropathy

Question 28

Gene for A1 Anti trypsin

Answer 28

SERPINA1

Question 29

Most common genotype for A1 antitrypsin

Answer 29

Pi*ZZ

Question 30

Genotype in alpha 1 antitrypsin associated with liver/lung disease

Answer 30

PI*ZZ

Question 31

Most common cause of familial FTD and MND

Answer 31

C90RF72

Question 32

Most common type deletion in DMD

Answer 32

Multiple exon deletion

Question 33

Microsatellites are?

Answer 33

1-5 nucleotide base pairs repeated multiple times Often on downregulating promoters. Instability shows characeristic features As they are repeats, susceptible to frame shift

Question 34

Finding a gene without knowing its function?

Answer 34

Positional cloning

Question 35

Copy number variations - Example of gain - Example of loss

Answer 35

Gain - PMP22 --> Charcot Marie Tooth Loss - PMP22 --> HNLPP

Question 36

Gold standard for CNV

Answer 36

Micro-array

Question 37

Other tests for CNV - FISH - benefit and drawback - MLPA - benefit and drawback

Answer 37

FISH - Can find location of gene - Drawback - need primer MLPA - Multiple primers, multiple genes (good for DMD) - Can't find location

Question 38

Gold standard for DMD diagnosis

Answer 38

MLPA

Question 39

Trinucleotide repeat fragile x

Answer 39

CGG

Question 40

Trinucleotide repeat myotonic dystrophy

Answer 40

CTG

Question 41

Lamin mutation and CM?

Answer 41

DCM

Question 42

Genetic testing for SCA

Answer 42

Fragment length analysis SCA gene loci with varying length of CAG repeats

Question 43

On which base does methylation of DNA occur?

Answer 43

Cytosine

Question 44

Detect uniparental disomy?

Answer 44

Microarray/CGH

Question 45

Detect loss of heterozygosity?

Answer 45

Microarray/CGH

Question 46

Pedigree - unaffected individual but affected parent and child?

Answer 46

Autosomal dominant with non-penetrance

Question 47

Is blood brain barrier lipophilic or hydrophilic?

Answer 47

Lipophilic