Clinical consequences of chromosomal disorders

Question 1

What is the polidy?

Answer 1

Ploidy is number of chromosomes in the cell nucleus

Question 2

What is non-disjunction?

Answer 2

the failure of chromosomes or sister chromatids to separate properly during cell division
results in daughter cells with abnormal chromosome numbers - aneuploidy

Question 3

What is mosaicsim?

Answer 3

2 or more different cell types present, originating from a single zygote

Question 4

When does mosaicism occur?

Answer 4

usually happens in embryo, thus after conception

Question 5

When does non-disjunction occur in mitosis?

Answer 5

in mitosis, non-disjunction during separation of sister chromatids

Question 6

What are microdeletions and microduplications?

Answer 6

Missing or extra chromosomal material

Question 7

What is more tolerated between monosomy and trisomy?

Answer 7

Monosomy less tolerated than trisomy (viability)

Question 8

What is translocation?

Answer 8

Rearrangement of chromosomes

Question 9

What are balanced translocation?

Answer 9

healthy, normal. At risk of
unbalanced offspring (miscarriages, infertility,
children with developmental, growth, physical
problems)

Question 10

What do unbalanced translocation depend on and what can this often lead to?

Answer 10

depend on size and position;
often developmental, growth, physical
problems)