Yes, I used GATK GetPileupSummaries and I used an interval file, this file was output from GATK RealignerTargetCreator tool.
Hi,
I am new to exome-seq and would be grateful for any suggestions :)
I want to run GATK CalculateContamination (GATK 4.1.8.1), before calling variants with MuTect2. CalculateContamination tool returns "SUCCESS" message, but with warnings, and I get only "0" values in my output file :
sample contamination error
my_sample 0.0 0.0
Here are warnings after running GATK CalculateContamination:
WARN KernelSegmenter - Number of points needed to calculate local changepoint costs (2 * window size = 100) exceeds number of data points (12). Local changepoint costs will not be calculated for this window size.
WARN KernelSegmenter - No changepoint candidates were found. The specified window sizes may be inappropriate, or there may be insufficient data points.
INFO KernelSegmenter - Found 0 changepoints after applying the changepoint penalty.
WARN KernelSegmenter - Specified dimension of the kernel approximation (100) exceeds the number of data points (12) to segment; using all data points to calculate kernel matrix.
Here is my code:
gatk CalculateContamination \
-I GetPileupSummaries_output.table \
-O CalculateContamination_output.contamination.table
I searched GATK documentation but didn't find any instructions there. I will be most grateful for any help :)
2 answers
If you used GATK GetPileupSummaries, did you use a VCF/interval list file that would have positions your input BAM would cover?
Hi @wiki97, I had the same issue using GATK 4.2:
Using BWA_MEM as aligner I get the:
WARN KernelSegmenter - Number of points needed to calculate local changepoint costs (2 * window size = 100) exceeds number of data points (12). Local changepoint costs will not be calculated for this window size. WARN KernelSegmenter - No changepoint candidates were found. The specified window sizes may be inappropriate, or there may be insufficient data points. INFO KernelSegmenter - Found 0 changepoints after applying the changepoint penalty. WARN KernelSegmenter - Specified dimension of the kernel approximation (100) exceeds the number of data points (12) to segment; using all data points to calculate kernel matrix. Followed by a SUCCESS message and plausible values
Using Bowtie2 as aligner I get: No warnings but the .contamination tables are
sample contamination error my_sample
1A 0.0 0.0
I don't really know why is happening this. Does anyone know if we can skip this part using GATK?
Log in to answer this question.