Difference between SNP and point mutation (Archived) - (Feb/04/2009 )

What is the difference between an SNP and a Point mutation? When is it called an SNP and when is it called a point mutation? :mellow:

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<!--QuoteBegin-kavitha+May 31 2005, 09:26 AM-->

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A SNP is a polymorphic base where the point mutation has persisted in the population. The term point mutation can occur as a one off event in only one individual. Generally, SNP studies look for bases that have greater than a certain minor allele frequency (e.g. 10% of the population have the minor allele) to show that the SNP is informative and exists in several individuals in a population.

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point mutation as the name implies has a delatrious or severe affect on the individual and is responsible for maybe premature termination of a message generating an aberant protein or no protein at all.

SNP's do not have this affect.

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Thank you kwing and methylnick for the info.

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Actually SNPs can have an affect on the individual, sometimes severe, for instance many cancers show SNPs in them, I would call that a severe effect!

bob

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<!--QuoteBegin-bob1+Jun 9 2005, 09:38 PM-->

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So then its still called an SNP even if it causes severe effects, since its present only in certain percentage of the population?

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bob1,

that's interesting! can you lead me to some references that show this?? Cheers

Nick

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Hi,

Here's a pretty good and simple website explaining SNP. Hope this helps.

http://www.ornl.gov/sci/techresources/Huma.../faq/snps.shtml

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Sure does, tnaks spate!

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Nice website, and damn precise too. We normally use the >1% criteria as a golden std. for when to call it a SNP and not a mutation. A mutation though also covers deletions/ insertions, SNPs dosent. I dont totally agree on the assumption about that a SNP cant be disease causing, it probably wont be a dominant disease causing SNP but perhaps recessive. ? Anyway SNPs are newbies in this game and we still lacks alot of information about those babies.

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<!--quoteo(post=16555:date=Jun 2 2005, 07:20 PM:name=methylnick)-->

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Sorry to disagree, methylnick, but the term "point mutation" describes only the extent of the mutation (as opposed to "deletion mutation" or "insertion mutation", for example) and says nothing about the consequenses (good, bad, or neutral) of the mutation.

Is it safe to say that all SNPs are point mutations, but not all point mutations are SNPs?

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SNPs are also point mutation. the mutation may or may not have an effect on gene's function. The difference between SNP and point mutation is that for a point mutation to be a SNP the minor allele of a SNP must be present at appreciable frequency (at least 1%) in the human population.

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<!--quoteo(post=33006:date=Nov 30 2005, 10:16 AM:name=pcrman)-->

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hi

i feel that SNP is a methodology or a technique by which we can identify the point mutation in various individuals of a given population. and point mutation is an incident that occurs in an individual of a population.

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when the rate of a specific mutation is more than 1% IN THE POPULATION,then it is calld polymorphysm (or single nucleotide polymorphysm) but when it's prevalence in the population is less than 1%,it;s called a mutation.