Hi Kyle,

Please see the answers below:


1) if start position is actually the 1st deleted base or the base before
the start of the deletion.

With deletions, chromStart is the first deleted base which is not like the
VCF format .

2) In the case of insertion, is start position is 1bp before the actual
insertion event.

For insertions, note that when you add 1 to chromStart, chromStart becomes
1 greater than chromEnd. So chromStart is the first base after the
insertion and chromEnd is the last base before the insertion. This is kind
of confusing, but in the end, the coordinate math for the length in
reference bases is 0.

If you have further questions, please contact the list: [email protected].

Vanessa Kirkup Swing
UCSC Genome Bioinformatics Group


---------- Forwarded message ----------
From: Chang, Kyle <[email protected]>
Date: Tue, Apr 17, 2012 at 1:55 PM
Subject: Re: [Genome] How are ucsc dbsnp indel positions reported
To: Vanessa Kirkup Swing <[email protected]>
Cc: "[email protected]" <[email protected]>, "Kakkar, Nipun" <
[email protected]>


 Right I understand that the positions are all 0-based, and I need to add 1
to get the same start coordinate as the genome browser.

What I want to know is 1) if start position is actually the 1st deleted
base or the base before the start of the deletion.
2) In the case of insertion, is start position is 1bp before the actual
insertion event.


Kyle



On 4/17/12 3:48 PM, "Vanessa Kirkup Swing" <[email protected]> wrote:

Hi Kyle,

Please see this FAQ on our coordinate system:

http://genome.ucsc.edu/FAQ/FAQtracks.html#tracks1


I hope that clarifies things for you. If you have further questions, please
email the list: [email protected].

Vanessa Kirkup Swing
UCSC Genome Bioinformatics Group




---------- Forwarded message ----------
From: *Chang, Kyle* <[email protected]>
Date: Tue, Apr 17, 2012 at 10:02 AM
Subject: [Genome] How are ucsc dbsnp indel positions reported
To: "[email protected]" <[email protected]>
Cc: "Kakkar, Nipun" <[email protected]>


Hi,

I have a question on how indel coordinates are reported in dbsnp tables.

Here is a deletion record in dbsnp 135. Is 'start' always the 1st deleted
base or is it like the vcf format which the start is always 1bp before 1st
deleted base?

E.g.
131    chr1    61341695    61341699    rs146746778    0    +    TTTA    TTTA
-/TTTA    genomic    deletion

Fo insertion, is 'start' reported as 1bp before insertion? So in this case,
I imagine there's a CA insertion between 92536832 92536833 in 0-base
coordinates.

E.g.
161    chr1    92536832    92536832    rs72159935    0    +    -    -
-/CA    genomic    insertion

Best,
Kyle


_______________________________________________
Genome maillist  -  [email protected]
https://lists.soe.ucsc.edu/mailman/listinfo/genome
_______________________________________________
Genome maillist  -  [email protected]
https://lists.soe.ucsc.edu/mailman/listinfo/genome

Reply via email to