genetic tests & technologies Flashcards
what are 4 types of genetic tests when testing for genetic conditions
diagnostic
carrier
predictive
prenatal
what is a type of genetic test to clarify familial relationships
paternity testing
what is a type of genetic test used to determine identity
genetic finger printing
where is genetic finger printing usually done
in a forensic laboratory
where is paternity testing usually done
in a private sector or a forensic laboratory
where are tests for genetic conditions usually done
they are offered in clinical genetics
give 7 reasons for carrying out genetic testing
1) to confirm a clinical diagnosis
2) to give info about prognosis
3) to inform management
4) to allow presymptomatic/predictive testing in close relatives
5) for carrier testing
6) to give accurate recurrence risks
7) for prenatal diagnosis
what is sanger sequencing
uses PCR to amplify regions of interest followed by sequencing of products
useful for single gene testing
what is next generation sequencing (NGS)
a massively parallel sequencing technology that offers ultra-high throughput, scalability, and speed.
used to determine the order of nucleotides in entire genomes or targeted regions of DNA or RNA
can sequence whole human genome in 1 day
multi-gene panels, whole exome/genomes
what is next-generation sequencing (NGS)
a massively parallel sequencing technology that offers ultra-high throughput, scalability, and speed.
used to determine the order of nucleotides in entire genomes or targeted regions of DNA or RNA
can sequence whole human genome in 1 day
multi-gene panels, whole exome/genomes
compare the starting point of sanger and NGS
sanger - single start point (primer)
NGS - library of DNA fragments
compare the sequencing of sanger and NGS
sanger - single DNA fragment sequenced
NGS - massively parallel sequencing
compare cost of sanger and NGS
sanger - high cost per gene
NGS - low cost per gene
compare time of sanger and NGS
sanger - time consuming
NGS - fast
compare data interpretation of sanger and NGS
sanger - simple analysis (read the sequence)
NGS - huge amounts of raw data to interpret
compare the accuracy of sanger and NGS
sanger - very accurate
NGS - moderately accurate
how do you analyse data from NGS
NGS generates millions of short DNA fragments that needed to be filtered for quality and aligned to a reference sequence
- need to reference genome
- identify variants
- interpret variants
- insilico tools
what is targeted panel sequencing
useful tools for analyzing specific mutations in a given sample
pros of targeted panel sequencing
select specific genes to sequence
less noise
fewer variants of uncertain significance
con of targeted panel sequencing
panels need to be updated
what are incidental/secondary findings
additional findings on a patient or research participant that may or may not have potential health implications and clinical significance, that are discovered during the course of a clinical or research investigation but are beyond the aims of the original test or investigation
