HI, I generated my own samples' variant or SNP calling table and plan to narrow down or filter these many of the variants using dbSNP. Here i downloaded two dbSNP with one from NCBI and another from Sanger. However, I doubt NCBI one has error when it called a nt variant change from C to T (see belows). IF it is a variant from reverse strand, it should be at least A to G replacement. I am so concerned about how many of these kinds of potential error in NCBI dbSNP which could influence my variant/mutation filtering?
Anyone has suggest on this? thank you
NCBI dbSNP
#CHROM POS ID REF ALT
10 3978708 rs29320259 C T
Sanger dbSNP
#CHROM POS ID REF ALT
chr10 3978708 rs29320259 T C
My own sample SNP calling
#CHROM POS ID REF ALT
chr10 3978708 3978708 . T C
1 answer
I see variants like this all of the time. Personally I do my filtering based on minor allele frequency, and not just the presence of a dbSNP id. If there is a dbSNP id with no known minor allele frequency it could be for a variety of reasons. Some of these are problematic regions of the genome and may represent fairly common false positives which you would want to filter out, but many others are simply SNPs that were deposited, often a long time ago, and never seen again in other sequencing projects.
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