Hello,

One method would be to: determine if the SNP is in a coding region of a 
gene, find out the reading frame of the gene, examine the SNP location 
in the target codon, then compare the resulting amino acid translations. 
This would be the simple one-base substitution. For more complex 
substitutions, more than one amino acid may be added/deleted/changed and 
the analysis would be similar but likely involving more than one codon. 
Please see the dbSNP track's description page for the types of 
categories SNPs can sort into.

To view in the Browser, load your SNP dataset as a custom track and 
compare to the UCSC Genes track (or any Gene prediction track) zoomed 
in, with protein translation annotation on (set this on the track's 
description page). You could first filter the uploaded SNPs using an 
intersection function in the Table browser to create a track that only 
contains the SNPs in a coding region.

Next, note the SNP location versus the gene's amino acids in the 
translation frame. Use an amino acid (aa) translation matrix to 
determine the aa when the alternate nucleotide is used and note if it is 
the same or different (synonymous or non-synonymous). Then at the next 
analysis level, determine if the new aa causes any significant changes 
in final protein product.

More automated methods are possible but the basic analysis path is the 
same.

Download/ftp gene track sequence (both mRNA and protein) from the 
browser and use your own tools to substitute the SNP base(s) in the 
mRNA. Then, do the translation in the Browser using DNA Duster (home 
page, left blue tool bar, click on Utilities, then DNA Duster) - be 
certain to use coding sequence only for accurate translations.

Then run a protein vs protein comparison program (such as BLAT or other) 
between the proteins containing the SNP and those in the public domain 
and analyze differences. Some programs will also interpret synonymous aa 
as matches and non-synonymous aa as mis-matches depending on the program 
and any parameter files (protein matrix files, etc.) it uses.

Or run a sequence comparison program with a mRNA (nucleotide) query 
containing your SNP(s) against an protein (aa) target (the "baseline or 
normal gene data set"). The program will do the translation of the query 
for you. Analyze differences

Table browser: http://genome.ucsc.edu/cgi-bin/hgTables
Data ftp instructions: http://genome.ucsc.edu/FAQ/FAQdownloads#download1

Please let us know if you have any questions about the UCSC Browser 
tools or data,
Jennifer Jackson
UCSC Genome Bioinformatics Group

Clarence K. Zhang wrote:
> Hello, 
>
>  
>
>   We have a set of novel snp which have not been annotated in dbSNP or any 
> other public database. The only information we have is the base substitution 
> and its location. 
>
>   
>
>   How can we determine whether or not it is a synonymous or non-synonymous 
> snp, from UCSC genome browser? 
>
>  
>
>  
>
> Thank you very much, 
>
>  
>
> Clarence K. Zhang, PhD
> Associate Research Scientist
> Keck Biotechnology Laboratory Biostatistics Resource
> Yale University School of Medicine
> 300 George Street, Suite 503
> New Haven, CT 06511
>
> 203-737-1123 (office)
> [email protected]
>
> _______________________________________________
> Genome maillist  -  [email protected]
> https://lists.soe.ucsc.edu/mailman/listinfo/genome
>   
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