Clinical genetics

Question 1

How many organs affected in multifactorial?

Answer 1

1 organ

Question 2

What factors make you susceptible to a multifactoral disease

Answer 2

Gene and enviroment

Question 3

What is a compound heterozygous

Answer 3

Both alleles affected

Different mutations

Question 4

Where is the deletion in sentinel deafness (SG)

Answer 4

G deletion in connexin 26

Question 5

What is mutated in Familial Hypercholesterolaemia (FH) what affect does this have? (SG)

Answer 5

LDL receptor
> Cholesterol not taken into tissue
>Elevated LDL cholesterol plasma levels

Question 6

FH symptoms (SG)

Answer 6

> Cholesterol Xanthelasma
Archs of cholesterol
Premature atherosclerosis

Question 7

FH treatment (SG)

Answer 7

> Inhibit HMG-co A reductase

Question 8

Downs syndrome symptoms (chr)

Answer 8

>Round Face
> Protruding tongue
>Upslanting Palpera fissures
>Epicanthic Folds
>Development Delay

Question 9

Downs syndrome on ultra sound (chr)

Answer 9

>Short femurs
>Knuckle translucency
>Choroid plexus cyst
>Sandal Gap
>Single palmer crease

Question 10

Cause of Di George (chr)

Answer 10

> Microdeletion chr 22

Question 11

Symptoms of Di george (chr)

Answer 11

> Congenital heart defects
Small mouth
Prominent Nose

Question 12

Cause of williams-Beuren (chr)

Answer 12

> Micro deletion chr 7

Question 13

Williams- Beuren symptoms (chr)

Answer 13

>Bright eyes
>Stellate iris
>Wide mouth
>Upturned nose
>Long Philtrum
>Flattened nasal bridge

Question 14

Give examples of variable Expressivity

Answer 14

Huntington
Neurofibromatosis
>Cafe au lait spots
>Benign neurofibromas

Question 15

Phenylketonuria symptoms

Answer 15

>Epilepsy
>Musty/ mousy odour
>Extrapyramidal Manifestations
>Impaired melanin synthesis
>Eye abnormality 
>Long head
>late delay
>Not treated
    >Intellectual disability
     >Behavioural problems

Question 16

What phase are chromatids in for the karotype and for staing

Answer 16

Metaphase

Question 17

What disease does this person have?

47 Xx + 21

Answer 17

Downs syndrome

Question 18

What chromosome abnormality does this person have?

46 Xy, del (5) (p25)

Answer 18

Deletion on chr 5

near tips

Question 19

What is a chiasma

Answer 19

Visible result of crossing over

Question 20

What afftect do change in gene dosage have?

Answer 20

> Balance of genes acting in a pathway

Question 21

Give a polyploidy example

Answer 21

Triploidy

Question 22

Give example of structural gene dosage abnormalities

Answer 22

Deletion
Inversion
Duplication
Translocation (robertsonian, reciprocal)
De novo

Question 23

When do de novo mutations occur? what does this mean>

Answer 23

Meiosis

Inherited

Question 24

When does non disjunction occur?

Answer 24

Meiosis 1

Question 25

What risk increases with age

Answer 25

De novo

Question 26

What is is called in non dis junction when two chromosomes go into the same gamete?

Answer 26

Disomic

Question 27

Symptoms of Patau

Answer 27

``` Multiple malformations Mid line: >Incomplete lobation of brain >Cleft lip >Congenital heart defects` ```

Question 28

Symptoms of Edward Syndrome

Answer 28

Multiple Malformations >Kidney & Heart >Clenched fist >Overlapping fingers

Question 29

Symptoms of Turner syndrome (Sex chr)

Answer 29

>Primary amenorrhoea >Wide carrying angle or arms >Congenital heart disease >Short

Question 30

Symptoms of klinefelter (sex chr)

Answer 30

``` >Weak muscle >Poor coordination >Tall >Dec. sex drive >Gynaecomastia >Less hair >small testicles >osteoporosis ```

Question 31

What occurs in reciprocal translocation?

Answer 31

>Exchange of similar structured genetic fragments between 2 non homologous chromosomes

Question 32

What are the 3 probes in FISH?

Answer 32

>Repetitive sequencing >DNA segment >specific >chromosome painting

Question 33

What templates are used in PCR?

Answer 33

Genomic Cloned cDNA

Question 34

What does FISH identify

Answer 34

>Structural and numerical abnormalities

Question 35

What does OLA 1 recognise?

Answer 35

>An A that recognises T

Question 36

What does OLA 2 recognise?

Answer 36

>A c that recognises a G