07d: Imprinting

Question 1

Define gene imprinting.

Answer 1

Phenomenon where only a single copy of gene is selected as active and other is silent based on parent of origin

Question 2

If maternal copy is silent, is the gene (paternally/maternally) imprinted?

Answer 2

Maternally

Question 3

The expression status of imprinted genes is determined during:

Answer 3

Gametogenesis

Question 4

Paternally-imprinted genes acquire these epigenetic marks during:

Answer 4

Spermatogenesis

Question 5

Chromosome 15q11-13 contains a differentially-imprinted region. What does that mean?

Answer 5

It is a region where some genes are expressed only from the maternal copy and others only expressed from paternal copy

Question 6

Paternal deletion of Chromosome 15q11-13 results in:

Answer 6

Prader-Willi Syndrome

Question 7

Maternal deletion of Chromosome 15q11-13 results in:

Answer 7

Angelman Syndrome

Question 8

What’s uniparental disomy?

Answer 8

Situation where both copies of particular chromosome are either maternally or paternally derived

Question 9

In uniparental disomy, are all chromosomes in genome derived from one parent?

Answer 9

No! Just the chromosome in question

Question 10

Maternal uniparental disomy is a situation that’s functionally equivalent to (X) deletion.

Answer 10

X = paternal deletion for imprinted region on that chromosome

Question 11

Is deletion or uniparental disomy more common? Or are they equally as common?

Answer 11

Deletion more common