Case Unit 3: Genomics Flashcards
What is linkage analysis?
Detection of the chromosomal location of genes, using the fact that genes that are located closer together are less likely to become separated during recombination
Why is linkage analysis useful?
Determining the chromosomal location of genes is the first step in isolating the gene, for developing therapies
What is a marker gene?
The gene that is closely linked to the ‘gene of interest’
Usually has a detectable phenotype e.g. production of an enzyme
How is linkage measured?
LOD score = how likely two genes are to be linked
A LOD score > 3 suggests linkage between the genes
What is a GWAS?
Genome Wide Association Study
Observational study
Many DNA samples ‘read’ using SNP arrays
Detects if any SNPs are over represented in particular populations, to suggest if any SNPs are associated with a trait or disease
What is trio analysis?
The exome (ONLY EXOME) of a patient (proband) and both their biological parents is sequenced Any variants, INDELs, CNVs or de novo mutations are detected
What is RNA sequencing?
Used to measure quantities of specific RNA in samples to identify levels of gene expression
Can be used to compare gene expression between cell populations, and discover which genes are upregulated in certain cells
How is RNA sequencing carried out?
Purify mRNA from samples
Use RT to convert mRNA into cDNA
Sequence the cDNA using NGS
Compare samples to see which genes are upregulated
How are the products of RNA sequencing analysed?
Look up the upregulated genes on software e.g. DAVID to find out what pathways it is involved in
Look for groups of upregulated genes that have similar functions e.g. are the all involved in DNA repair?
Helps to design a treatment
