This is a test version of Biostars. For the public version, visit https://www.biostars.org.
Corrupted dbsnp-vcf?

Hello,

I have a vcf file, which I want to upload on the Sanger Imputation server. The following error occured:

--- Aborted Job ---
The input file sanity check failed, "bcftools norm -ce" exited with the following message:
Reference allele mismatch at X:3155141 .. REF_SEQ:'T' vs VCF:'G'

As suggested by the sanger website, I wanted to solve this issue with the bcftools +fixref command.

All my SNPs have dbsnp-IDs, so I downloaded the following file for reordering alleles: ftp://ftp.ncbi.nih.gov/snp/organisms/human_9606_b151_GRCh37p13/VCF/All_20180423.vcf.gz

When I now use the

bcftools +fixref broken.vcf -O z -o fixref.vcf -- -d -f /path/to/reference.fasta -i `All_20151104.vcf.gz`

command, the following error appears:

[E::bgzf_uncompress] Inflate operation failed: invalid distance too far back
[E::bgzf_read_block] Invalid BGZF header at offset 15203091877

It seems, that the All_20151104.vcf.gz file is corrupted. I also am not able to index it with bcftools. However, another operation (subsetting it to regions) works...

Does anyone know, how to solve this problem?

Best,

Andreas

bcftools vcf imputation

hg19: chrX:3155141 is T

hg18: chrX:3155141 is G

aren't you mixing hg* builds ?

I think/hope not...everything should be hg 19... Might be a stupid question, but where can I quickly check this for some SNPs?

1 answer

Ok I solved it! The problem was the following: During the preprocessing, I converted plink files to vcfs and assumed the first allele in the bim file to be the reference allele...however, it is not! I now solved it by using the --ref-from-fa command when making vcf files.

Log in to answer this question.