Genetics

Question 1

Behcet’s Syndrome
Associated HLA

Answer 1

HLA 51

Question 2

Osteogenesis Imperfecta
Associated collagen defect

Answer 2

Type 1 collagen

Question 3

Oncogenes
- Normal function
- Abnormal function
- Examples (2)

Answer 3

Normal = promote signal pathways of cell growth
Abnormal = dominates, loss of growth control
e.g. RAS - G protein
e.g. c-myc - transcription factor
- Associated with Burkitt’s lymphoma

Question 4

C-myc
- Type of gene
- Association

Answer 4

= oncogene
Burkitt’s Lymphoma

Question 5

RAS
- Type of gene

Answer 5

= oncogene

Question 6

Tumour suppressor genes
- Normal function
- Abnormal function
- Examples (2)

Answer 6

Normal = inhibit the cell cycle
Abnormal = loss of function, loss of growth control
e.g. p53
e.g. Rb gene
- Associated with retinoblastoma

Question 7

Rb
- Type of gene
- Association

Answer 7

= tumour suppressor gene
Retinoblastoma

Question 8

p53
- Type of gene
- Function
- Association

Answer 8

= tumour suppressor gene
Regulates apoptosis
Li-Fraumeni

Question 9

Trisomy 21
- Most common cause
- Cardiac presentations (3)

Answer 9

Maternal non-dysjunction
- ASD (failure of fusion of inferior and superior cardiac cushions)
- PDA
- Tetralogy of Fallot

Question 10

Patau’s Syndrome

Answer 10

Trisomy 13

Question 11

Edward’s Syndrome

Answer 11

Trisomy 18

Question 12

Abnormality in CML

Answer 12

Philadelphia Chromosome
9:22 translocation

Question 13

9:22 translocation

Answer 13

= Philadelphia chromosome
CML

Question 14

APC
- Type of gene
- Location

Answer 14

= tumour suppressor gene
- Chromosome 5
- Familial adenomatous polyposis

Question 15

Lynch Syndrome
- Genetic problem
- Inheritance

Answer 15

= DNA mismatch repair
- Autosomal dominant

Question 16

Inheritance - Tuberous Sclerosis

Answer 16

A dominant

Question 17

Inheritance - hereditary spherocytosis

Answer 17

A dominant

Question 18

Inheritance - Charcot Marie Tooth (HSMN)

Answer 18

A dominant

Question 19

Inheritance - Myotonic dystrophy
- Abnormality

Answer 19

A dominant
- Protein kinase trinucleotide repeat

Question 20

Inheritance - achondroplasia
- Abnormality

Answer 20

A dominant
- fibroblast 3 mutation

Question 21

Inheritance - cystic fibrosis
- Abnormality

Answer 21

A recessive
deletion mutation

Question 22

Inheritance - inborn errors of metabolism
Examples (5)

Answer 22

A recessive
Gaucher disease
PKU
Tay Sach’s
Homocystinuria
Glycogen storage disease

Question 23

Genetic abnormality in Huntington’s Disease
- Chromosome

Answer 23

Trinucelotide repeat
Chromosome 4

Question 24

Genetic abnormality in Frederich’s Ataxia
- Inheritance
- Chromosome

Answer 24

Trinucelotide repeat
Autosomal recessive
Chromosome 9

Question 25

Trinucelotide repeat disorders - What do they demonstrate? - Effect of age?

Answer 25

Genetic anticipation = presents at earlier age with each generation Repeats expand with age = somatic instability

Question 26

Inheritance - G6PD deficiency

Answer 26

X linked recessive

Question 27

Inheritance - Duchenne and Becker Muscular Dystrophy - Mutation type - Severity

Answer 27

X linked recessive Duchenne = nonsense mutation, more severe Becker = in frame mutation, less severe

Question 28

MHC - What is it? - Where is it found?

Answer 28

Major histocompatibility complex - Chromosome 6

Question 29

Class I MHC - Where found? - Subclasses? - Immune response cell?

Answer 29

All nucleated cells HLA-A, HLA-B, HLA C - get one each from each parent CD8+ T cells respond - involved in ACUTE rejection

Question 30

Class II MHC - Where found (3)? - Subclasses? - Immune response cell?

Answer 30

Dendritic cells, B cells, monophagocytes DR2, DR3, DR4 CD4+ T cells

Question 31

HLA3

Answer 31

Haemochromatosis

Question 32

Haemochromatosis

Answer 32

HLA-A3

Question 33

HLA B51

Answer 33

Behcet's Disease

Question 34

Behcet's Disease

Answer 34

HLA B51

Question 35

HLAB27 (4)

Answer 35

Ankylosing spondylitis Psoriatic arthritis Reiter's syndrome Anterior uveitis

Question 36

HLA DR2

Answer 36

Multiple sclerosis

Question 37

Multiple sclerosis

Answer 37

HLA DR2

Question 38

HLA DR3 (6)

Answer 38

Dermatitis herpetiformis/coeliac disease T1DM Grave's Disase SLE PBC Myaesthenia gravis

Question 39

Dermatitis Herpetiformis

Answer 39

HLA DR3

Question 40

Acute transplant rejection - Immune cell in control - How occurs

Answer 40

T cell mediated - dendritic cells found in transplant migrate to local lymph nodes and activate T cells

Question 41

T1DM

Answer 41

HLA DR3 HLA DR4

Question 42

Rheumatoid Arthritis

Answer 42

HLA DR4 - Specifically DRB1

Question 43

Hyperacute rejection - Immune cell in control - How occurs

Answer 43

B cell mediated - Antibodies formed due to previous sensitisation BIND to endothelium - Destruction of implant

Question 44

Genetic mutation associated with prostate cancer

Answer 44

BRAC2 (also BRAC1 but not as much)

Question 45

Mode of inheritance - frederich's ataxia

Answer 45

Autosomal recessive Frederichs ataxia is excessive (recessive)

Question 46

Association with Oropharyngeal cancer

Answer 46

HPV 16/18

Question 47

Which part of the cell cycle determines the length?

Answer 47

G1 - cell spends most of its time here: prepares for DNA replication

Question 48

Translocation associated with follicular lymphoma

Answer 48

14:18

Question 50

Translocation asscoiated with AMPL

Answer 50

15:17

Question 51

Collagen mutation in Ehler's Danlos

Answer 51

Collagen Type 3 E and 3 are mirror image

Question 52

Ataxic Telangiectasia - gene implicated

Answer 52

ATM gene

Question 53

Technique used for DNA sequencing?

Answer 53

Southern Blotting