L12 Molecular Diagnosis III - most info is on review sheet

Question 1

what are the 3 types of point mutations?

Answer 1

silent
missense
nonsense

Question 2

what is a silent mutation

Answer 2

does not change amino acid code

Question 3

what is a missense mutation

Answer 3

changes protein

Question 4

what is a nonsense mutation

Answer 4

creates a stop codon

Question 5

what is a transition mutation

Answer 5

purine to purine (A -> G or (G -> A)
or
pyrimidine to pyrimidine (T -> C or C-> T)

Question 6

what is a transverse mutation

Answer 6

purine to pyrimidine or vice versa

less common than transition

Question 7

what is a characteristics of amplification of repeat sequence?

Answer 7

instability

Question 8

what happens in regulatory

Answer 8

alteration of promoter sequence

Question 9

what happens in triple repeat

Answer 9

gain of function

Question 10

what happens during inframe deletion and insertions?

Answer 10

multiple of 3 (ACG etc) is added or taken out of strand
usually leads to no serious effect
except in CF, we delete F508 (Phe) and = CF

Question 11

what is an out of frame mutation

Answer 11

delete or add one letter
all aa codes will change
if early in gene, likely to make a stop codon early
if late, likely to extend the chain

Question 12

what are splice donor mutations

Answer 12

leads to including an intron in the mRNA

if stop codon is in intron, it leads to shorter protein product

Question 13

what happens in a splice acceptor mutation

Answer 13

you lose an exon