Most Variants Called <2.0 Quality of Depth (QD) in VCF files
So I am forced to do hard-filtering on my VCF files. Looking at them before filtering, ~99% of my variants have a QD of <2.0. Looking at the distribution plots in ggplot, they do not follow the same distribution pattern as seen in http://gatkforums.broadinstitute.org/gatk/discussion/6925/understanding-and-adapting-the-generic-hard-filtering-recommendations. I have 24 samples and they are not at all similar in their distribution.
The other FS and MQ are all within the recommendations. I wasn't sure where the values for ReadPosRankSum and MQRankSum were as so couldn't plot those out.
I have used a ploidy of 20, and I'm looking at a population of bacteria. Does anyone know why the QD is so low?
I'm going to reduce the recommended filtering QD cut off to 0.8, therefore, sampling the top ~10% of variants by QD. Does that seem sensible?