Lecture 6: Chromosome Rearrangement Flashcards
What are the names of the two types of chromosome abnormality?
Constitutional abnormalities
Somatic abnormalities
Define Chromosome abnormalities (2 possible answers)
Changes that produce a visible alteration of the chromosomes
Abnormality produced specifically by chromosomal mechanisms
What does Constitutional abnormalities mean for the body?
The chromosome abnormality is present in every cell in the body
What does Somatic abnormalities mean for the body?
Present in only certain cells or tissues
Mentions something about fall into two categories either copy number alteration or
structural abnormality? Jesus theres a whole table 4-6
What is an inversion?
When a chromosome sustains two breaks and the fragment is switched around in the reverse direction
Can involve the centromere
What can inversions affect? (2 points)
Chromosome segregation
Can disrupt genes or affect gene expression
If 2 chromosomes have a break will the outcome be the same?
No.
The same chromosomal breakage can result in different outcomes
E.g
Deletion and inversion can happen in one
While in the other inversion could be seen and the other broken ends join together etc
There’s an image of the consequences on slide 9
What is translocation?
When a chromosome breaks (usually two) and fragmented pieces re-attach to different chromosomes
What can happen to the end result of chromosomes if something goes wrong during translocation?
??????? reciporcal translocation
robersonian translocation slide 10
What are the 5 acrocentric chromosomes that are affected in Robertsonian translocation?
13
14
15
21
22
What are acentric chromosomes composed of? (2 points)
rRNA genes
Heterochromatic DNA
What can be a result of Robertsonian translocation?
Occurs via a centromere proximal exchange resulting in a dicentric (mitotically stable) and acentric (unstable) chromosomes
