SEQanswers

Go Back   SEQanswers > Bioinformatics > Bioinformatics



Similar Threads
Thread Thread Starter Forum Replies Last Post
HD SNP chip data Jayakumar S Bioinformatics 0 07-01-2015 03:05 AM
SNP calling from multiple genotypes sgcsd Bioinformatics 4 11-21-2013 01:52 PM
snp.cns to GFF3 conversion reena_narayanan Bioinformatics 0 05-10-2011 01:39 AM

Reply
 
Thread Tools
Old 09-30-2015, 10:46 AM   #1
clarissaboschi
Member
 
Location: US

Join Date: Apr 2010
Posts: 63
Default Genotypes conversion (SNP chip)

Hi all,
I have a big input file from 28 individuals which were genotyped by 600 K SNP chip (Affymetrix). I have about ~500,000 genotypes for each individual.
But my file has a particular format for the genotypes, which is:

-1= no call
0=AA (homozygous for the reference allele)
1=AB
2=BB (homozygous for the alternative allele)

My file is:
AX-51 2 1 2 1 1 2 1 2 1 2 2 1 1 2 0 2 2 2 0 1 0 2 2 1 2 2 -1 2
AX-58 2 2 2 2 2 1 1 2 1 2 1 2 2 2 1 2 2 2 2 2 2 2 2 1 2 2 2 2

I have another file with the alleles information and position (map file):
SNP_ID Chr Pos Alele_A/Alele_B
AX-751 1 306 T/C
AX-758 1 727 A/G

I need to convert the file 1 with their respectives alleles. I tried to use Plink, but I was not able to convert the file.

Any suggestion??

thanks
Clarissa
clarissaboschi is offline   Reply With Quote
Old 10-02-2015, 05:43 AM   #2
WhatsOEver
Senior Member
 
Location: Germany

Join Date: Apr 2012
Posts: 215
Default

I have no experience with SNP chip data no can I suggest an existing program that is able to this, but from your description it seems to be a rather simple lookup problem for which some self-coding should be sufficient.

What you need to do is reading linewise through your file:
AX-51 2 1 2 1 1 2 1 2 1 2 2 1 1 2 0 2 2 2 0 1 0 2 2 1 2 2 -1 2
.

For each line you take the SNP_ID in the beginning and look for its corresponding genotype in the map file (for AX-51 you may get refGeno = A / altGeno=G)

Afterwards you simply go through the fields of the prediction and replace the numbers with the genotypes (e.g. if "0" then refGeno, elif "2" then altGeno, ...)

If you have no programming experience, you might even use excel/open office (vlookup) for this. Certainly not the best way to do, but still possible
WhatsOEver is offline   Reply With Quote
Reply

Tags
affymetrix, chip, genotypes, snp

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off




All times are GMT -8. The time now is 08:24 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Single Sign On provided by vBSSO