EXAM 3: ch.12 (SNPS) Flashcards
when is a common time that SNP analysis is needed?
to resolve potential relatives from another
what are AIMS? how are they useful?
ancestral informative markers
- useful in estimating the ethnic origin of a sample
true or false: genetic markers for physical traits may be discovered to enable phenotypic evaluation
true
what does SNP stand for ?
single nucleotide polymorphisms
___ million sites in the human genome where SNP’s could occur
15
__ million SNPS catalogued in ___ individuals
3.8
270
each person has ~ ___ common SNPS and ~___ new mutations have arisen
3.5
30
SNPS are used for __
- identification and forensics
- mapping for genome diseases
- estimating predisposition to disease
- paternal testing
- immigration & citizenship in UK
- specific genetic traits
- classifying patients in clinical trials (drug efficiency and drug reactions)
some variations cause disease, for SNP can these variations cause disease?
not rare
name the noncoding SNP’s
- 5’ UTR
-3’ UTR - introns
-intergenic regions
-pseudogenes - regulatory : splicing, transcriptional regulation, translational regulation, regulatory miRNA target sites
what are the coding SNPS
- synonymous SNPS (third position variation)
- replacement SNPS (change amino acid; function or non-functional SNP’s)
what are the pros for SNPs
-small size
-less electrophoretic space
- no stutter
-no size separation
- use for degraded DNA
- phenotype
cons for SNPs
-multiplexing 40-50 SNPs (13 STR)
- less information than STRs
- not good for mixtures
what are the applications of SNPs
HID
ancestry
lineage
phenotype
___ widely used in casework and national databases
STRs
___ smaller versions of STR loci that can work well on degraded DNA
miniSTR
__ permits examination of male-only DNA
Y-STR
__ used in specialty labs for highly degraded specimens or hair that contains limited amounts of DNA
mtDNA
__ potential for identifying ethnicity of evidence sample; still in research and likely to be limited in use
SNPs
is it likely that SNPs will replace STR in the future?
it is uncertain, but unlikely that it will due to the difficulties with mixed sample interpretation
what are the 3 specific reasons why SNPs will not replace STR
- large databases containing STR information would need to be replaced
- mixture detection and interpretation benefits from marker systems with many alleles and SNPs only have 2
- degraded DNA can be successfully analyzed in many cases by minSTR ( removing primary motivation of SNPs)
what are some other applications of SNPs (other than forensics)
- medical diagnostics (cancers)
- pharmacogenomics (personalized medicine)
- genetic linkage studies (SNP haplotyping)
advantages of STR , disadvantages of STR
A; - higher PD, multiplexes available, databases established, familiar instrumentation
D; limited abundance, stutter, extremely degraded samples
Are there ethical challenges with using SNPs to predict
ethnicity and physical traits? If so, what are they and
how should the law enforcement community use this
type of information in the future
yes there are which is why they are cautious for future testing and information
Why are SNPs being considered for use in human
identity testing?
- small size, help degraded DNA, used for phenotype
what is the popular SNP analysis technique
SNaPshot; a mix that is within the primer extension (after multiplex PCR of the genomic DNA sample) , following is the cycle sequencing, then SAP treatment