Question: Filter out supplementary aligned reads for variant calling or not
gravatar for gb
8 weeks ago by
gb1.8k wrote:

Dear all,

I am using BWA-mem and freebayes to do some variant calling and I was wondering if I should remove the supplementary aligned reads or not. I can not find much info about this.

snp bwa freebayes • 101 views
ADD COMMENTlink written 8 weeks ago by gb1.8k

In general it is good practice to not do any custom filtering unless the manual of the tool you use specifically recommends it. You should have duplicates marked in the BAM. Any proper variant caller will then internally choose the reads that based on its underlying model or strategy are suitable. The README ( does not mention any prefiltering so you should not do it.

ADD REPLYlink modified 8 weeks ago • written 8 weeks ago by ATpoint34k

I think that is a good point. For now I will not worry about this.

ADD REPLYlink written 8 weeks ago by gb1.8k

If you later during analysis of the results see that something is wrong you can still dig deeper if supp. alns might be a factor but I doubt so. I learned over the years that one should not overthink things and only start to debug if there is evidence for something going wrong. It might cost a lot of time without making a positive difference.

ADD REPLYlink written 8 weeks ago by ATpoint34k
Please log in to add an answer.


Use of this site constitutes acceptance of our User Agreement and Privacy Policy.
Powered by Biostar version 2.3.0
Traffic: 1269 users visited in the last hour