Chromosomal abnormalities 2 Flashcards
What are the types of inversion?
Paracentric
Pericentric
What is a paracentric inversion?
Inversion occurs in the arm of the chromosome only
What is a pericentric inversion?
Inversion occurs across both arms, involves centromere
What are the types of deletions/duplications?
Terminal
Interstitial
What is a terminal deletion/duplication?
Deletion/duplication occurs towards end of chromosome
What is an interstitial deletion/duplication?
Occurs in the interior of the chromosome
What technique is used to identify deletions/duplications?
Chromosomes in metaphase spread
What technique is used to identify microdeletions/duplications? Why?
FISH
can’t see in banding pattern of chromosomes in metaphase spread
What can cause deletions/duplications in meiosis?
Uneven pairing
followed by crossing over and recombination
What is uniparental disomy?
Both homologous chromosomes are from one parent
What are the types of uniparental disomy?
Isodisomy
Heterodisomy
What is isodisomy?
Chromosomes from one parent are identical
What is heterodisomy?
Homologous chromosomes from one parent
When does uniparental disomy have an effect on the phenotyoe?
When the chromosomes involved are imprinted chromosomes
What are imprinted chromosomes?
Refers to how with certain chromosomes, the copy of the gene that is expressed is picked based on the parent it’s from
