[2.1] Chromosomal Mutations Flashcards
also known as Chromosomal aberrations
Chromosomal Mutations
Chromosomal abnormalities:
Abnormal Number
Aneuploidy
Chromosomal abnormalities:
Alterations
Structural
Variation of 2 Chromosomal Mutation
- Chromosome Structure
- Chromosome Number
4 chromosome structure
- Duplication
- Deletion
- Inversion
- Translocation
2 chromosome number
- Aneuploidy
- Polyploidy
One or more individual chromosome pair, either “up” or “down”
Aneuploidy
If normal = 46 chromosome,
then _______ = 45 chromosome or 47 chromosome
Aneuploidy
One or more complete chromosomes sets added
Polyploidy
If normal = 2n, then _____= 3n, 4n, 5n, etc…
Polyploidy
Failed to separate or segregate at anaphase
Non-disjunction
Two or more different cell lines in one person
Mosaicism
Doubling of segment of a chromosome
Duplication
3 Forms of Duplication
- Tandem duplication
- Reverse duplication
- Terminal tandem duplication
Example:
ABCD·EFEFGH
Tandem duplication
Example:
ABCD·FEEFGH
Reverse duplication
Example:
ABABCD
Terminal Tandem duplication
[Starts at the END]
4 Effects of Duplication
- Utero reproduction
- Craps shoot
- During Prophase 1 and M, Synapsis
- Unbalanced gene dosage
3 syndrome of Duplication
- Pallister Killian syndrome (extra #12 chromosome)
- Potocki-Lupski syndrome (17p11.2)
- Fragile X syndrome (Xq27)
Syndrome of Duplication:
Extra 12 chromosome, intellectual disability, prominent forehead, poor muscle tone, coarse facial features
Pallister Killian syndrome
Syndrome of Duplication:
Extra copy small of 17 chromosome, weak muscle tone, swallowing difficulty
Potocki-Lupski syndrome
Syndrome of Duplication:
also known as “17p11.2”
Potocki-Lupski syndrome
Weak muscle tone is called
Hypotonia