Molecular

Question 1

What is the preferred sample type for DNA or RNA extraction?

Answer 1

EDTA whole blood

Question 2

What are the key steps in PCR and the temperatures at which they take place?

Answer 2

1. Denaturation (DNA separated into 2 strands) - 95C
2. Annealing of primers (68C)
3. Elongation (72C)

Question 3

What is used in Sanger sequencing to prematurely terminate DNA sequence?

Answer 3

Di-deoxynucleotides

Question 4

What level of DNA testing are HFE and TPMT?

Answer 4

Level 1 DNA test (standard)
Consent is implied by request testing

Question 5

What level of DNA testing is BRCA1 and HD?

Answer 5

Level 2 DNA test (i.e. the test has the potential to lead to complex clinical issues.)
Must obtain written informed patient consent.

Question 6

Most common mutations associated with Type 1 hereditary haemochromatosis (HFE gene)?

Answer 6

• C282Y – the amino acid tyrosine issubstituted
  for a cysteine at position 282, and
• H63D – the amino acid aspartate is substituted
  for a histidine at position 63.

Question 7

Mutations of HFE gene associated with milder phenotype of haemochromatosis (type1)?

Answer 7

H63D
S65C

Question 8

Inheritance pattern of Hereditary Haemochromatosis (type 1)

Answer 8

Autosomal recessive.

Question 9

Conditions that are included in Medicare rebatable Reproductive Carrier Screen

Answer 9

Cystic Fibrosis
Spinal Muscular Atrophy
Fragile X syndrome

Question 10

Butyrylcholinesterase deficiency affects metabolism/recovery from..

Answer 10

Succinylcholine

Prolonged paralysis can occur from reduced metabolism

Question 11

Testing for suspected Butrylcholinesterase deficiency

Answer 11

• Enzyme level
• Dibucaine inhibition (Phenotype)
• BCHE gene (AR inheritance - Heteroygous or homozygous)

Normal enzyme - will be largely inhibited by dibucaine