Mutations And Genetic Analysis

Question 1

What are structural abnormalities?

Answer 1

Balanced or unbalanced rearrangements
Translocation - reciprocal or robertsonian

Deletions
Insertions
Inversion

Question 2

What are the main 3 numerically abnormal syndromes?

Answer 2

Down (chromosome 21)
Patau (chromosome 13)
Edwards (chromosome 18)

Question 3

Reciprocal translocation

Answer 3

Increased risk of death before birth

Question 4

Robertsonian translocation

Answer 4

Loss of short arms

Question 5

Deletions

Answer 5

Due to breaks in chromosome - chunk of genetic material missed out

Question 6

Inversions

Answer 6

Breaks in chromosome, swapped over - reinserted pieces of DNA

Question 7

Genetic mutations

Answer 7

Polymorphism - no phenotypic effect
Gene disruption/ disease-related

Non - coding, potentially no effect
Silent, missense, nonsense, Frameshift (deletion/insertion)

Question 8

Mutation nomenclature

Answer 8

Cys64Arg - 64th chromosome, change from cystine to Argenine

Question 9

CDNA

Answer 9

DNA sequence with introns already spliced.

Question 10

Detecting mutations

Answer 10

PCR

Gel electrophoresis

RFLP (restriction fragment length polymorphism)

(ARMS) amplification refractory mutations system

DNA sequencing

Question 11

What do we need for PCR?
Technique?

Uses?

Answer 11

Sequence information, primers, DNA, nucleotide, DNA polymerase

Denature at 93 degrees (split), anneal 50-70 degrees, extend 70-75 degrees repeat 20-30 times.

Cloning
sequencing
Gene identification
Forensic medicine
Detection of mutations

Question 12

ARMS - mutation identifying process

Answer 12

Amplification refractory mutation system

Advantages: Cheap, electrophoresis required, primer design critical

Question 13

DNA sequencing

Answer 13

Finds mutations
Chain termination method (Sanger)

Poor quality and expensive
Has revolutionised the way we look at genome sequences