Genetics Flashcards
How much of a genome is affected in aneuploidy?
Entire chromosome
How much of a genome is affected in a chromosomal translocation?
100 megabases
How much of a genome is affected in a deletion?
10 megabases
How much of a genome is affected in a microdeletion?
5 megabases
How much of a genome is affected in the deletion of part of a gene?
1000 bases
How much of a genome is affected in a point mutation?
1 base
How do we detect aneuploidy, a chromsomal translocation or a deletion?
Standard karyotype
How can we detect a slightly smaller deletion or a microdeletion?
Fluorescence in-situ hybridisation
How can we detect the deletion of part of a gene?
Multiplex Ligation Dependent Amplification
How can we detect a point mutation?
PCR amplification and sequencing
What does Array Comparative Genomic Hybridisation detect?
Chromosomal imbalance
How do we know if a change causes disease?
Gene matches phenotype
Has an effect on gene function
Not listed as a polymorphism
It is an evolutionary conserved bit of a gene
De-novo in a child:
- Only the child is affected
Present in other affected family membersWho is a causative mutation found in?
Affected people (not in unaffected)
Do all affected people with a causative mutation have a condition?
No -> Beware of penetrance
What are the first line investigations into a suspected genetic abnormality?
Creatinine kinase
TFTs, U+Es, Bone group
LFTs, FBC and film
Chromosome microarray, Fragile X
