## Notice: Bug affecting ReduceReads -- GATK versions 2.0 and 2.1

### Posted by Geraldine_VdAuwera on 24 Sep 2012 (0)

We have identified a major bug in ReduceReads -- GATK versions 2.0 and 2.1. The effect of the bug is that variant regions with more than 100 reads and fewer than 250 reads get downsampled to 0 reads.

This has now been fixed in the most recent release.

To check if you are using a buggy version, run the following:

    samtools view -H \$BAM

This will produce the following output:

    @PG ID:GATK ReduceReads VN:XXX

If XXX is 2.0 or 2.1, any results obtained with your current version are suspect, and you will need to upgrade to the most recent version then rerun your processing.

Our most sincere apologies for the inconvenience.

#### GATK Dev Team

###### @gatk_dev

@hoffsbeefs Yes, multithreading can explain some marginal differences. For purely deterministic behavior, it should be disabled.
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