Definitions Flashcards
(22 cards)
Define epigenetics
Heritable and transient changes in gene expression that do not alter the primary transcript
- switches genes on/off
- contributes to variable expression in different cell types
3 mechanisms of epigenetics
DNA methylation
Histone modification
rna associated silencing
Define acetylation
Adds acetyl group (COCH3) to free amino groups of lysine dot arginine
Acetylation usually associated with increased transcriptional activity
Deacytylayion generally associated with repression of transcription
Define imprinting
Epigenetic change resulting in silencing of one copy of genes in parent specific manner
Define UPD
Uniparental disomy
- inheritance of both homologues of a particular chromosome from a single parent
Define Uniparental isodisomy
Presence of two identical copies of one parental homolog (likely meiosis II Nondusjunctuon or mitotic error)
Define uniparental heterodisomy
The presence of both homologues from one transmitting parent (likely meiosis I error)
Define audit
The review of process, procedure or outcome to see how accurate and effective it is at confirming to set standards followed by implementing changes if required and re-auditing.
Define clinical audit
Quality improvement process that seeks to improve patient care and outcomes though systematic review of care against explicit criteria and implementation change
Part of clinical governance
Define clinical governance
A system through which NHS organisations are accountable for continually improving quality of their services and safeguarding high standards of care by creating an environment in which excellence in clinical care can flourish
Define risk
Potential that a chosen action, inaction or activity will lead to an undersea me outcome
Define sensitivity
proportion of those with condition who test positive
Also known as detection rate
High sensitivity means screen captures as many people with disease as possible
If 100% don’t miss any (1-false negative)
Define specificity
Proportion of those without condition who test negative
High specificity means the screen has as few false positives as possible
How well the test excludes people if they are healthy.
Define QALY
Quality adjusted life year
Measure of state of health in which benefits in terms of length of life are adjust to reflect quality life
Value for money of interventions
1 QALY - 1 year of life in perfect health
0= dead
Calculated by estimating years of life remaining following treatment and weighting each year with a quality life score (0-1)
Define transcriptome
Complete set of transcripts in a cell and their quantity for a specific developmental stage or physiological condition
Generic recurrence risk for devnovo mutation?
1%
Define economy of scale
Saving in cost gained by increasing production
Define LRG
Locus reference genomic
Sequence format developed to aid curation of locus specific databases
Have fixed sequence so independent of the genome so provide stable framework
Define prognosis?
Likely course of medical condition
Define constraint
Genes intolerance to variation
Positive z score increased constraint - intolerant to variation - gene has fewer changes than expected
Negative z score - more variants than expected - tolerant to change
Define stop loss mutation
Mutation in the termination codon
Define stratified medicine?
Right treatment
Right patient
Right time
Using biological markers to separate patients into specific groups and treating by inactivationof well defined target or biological pathway
Stratification is one step toward personalised medicine
