Molecular pathology

Question 1

what are the advantages to molecular analysis?

Answer 1

1. very sensitive - allows for small sample size 2. not dependent on analysis of gene product - almost any cell will work

Question 2

which of the following can only be detected by molecular techniques: genome mutations, chromosome mutations, gene mutations?

Answer 2

gene mutations

Question 3

beta thalassemia is an example of what type of mutations?

Answer 3

1. mutation in promotor or enhancer (decreased expression) 2. mutation in poly-A tail at 3’ end of gene (unstable mRNA)

Question 4

what is the principle behind RFLP (restriction fragment length polymorphism)?

Answer 4

a change in the pattern of restriction endonuclease digestion is correlated with a genetic defect

Question 5

what is the direct method of mutant gene detection?

Answer 5

mutation creates or destroys a restriction endonuclease recognition site or there is a deletion or insertion in the gene so that the distance between two recognition sites is significantly changed

Question 6

which technique can be used to detect a mutant gene in a mixture of normal and abnormal (neoplastic) cells?

Answer 6

allele specific extension strategy (direct)

Question 7

what is the indirect method of mutant gene detection?

Answer 7

a particular restriction endonuclease digestion pattern or length polymorphism is correlated with having the disease but the mutation responsible for this pattern is not actually the cause of the disease

Question 8

what is the requirement for indirect mutant gene detection?

Answer 8

1. polymorphism used for detection must be sufficiently close to the mutated gene so that the marker and the mutation are inherited together 2. DNA from many individuals of extended family

Question 9

when can allele specific extension be used?

Answer 9

1. when causal mutation always occurs at the same site 2. with mixtures of cells (tumors)

Question 10

when is spectral karyotyping used?

Answer 10

to detect rearrangements and other chromosomal abnormalities (visualizing all of the human chromosomes at once)