In addition to the standard VCF format, megSAP creates variant lists in GSvar format in most analysis pipelines.
The GSvar format is a tab-separated text format which can be opened and filtered for example in Excel.
There are several ways to filter variant lists in GSvar format to identify rare pathogenic variants:
- The file can be filtered in Microsoft Excel.
- The file can be filtered on the Linux command line using the VariantFilterAnnotations tool of ngs-bits.
- The file can be filtered interactively on Windows using the GSvar tool if ngs-bits (more documentation on GSvar coming soon).
Similar to VCF format, the GSvar format can contain meta data in header lines that start with ##
:
-
The
##ANALYSISTYPE=
header specifies the analysis type. It can be present only once. Valid analysis types are:
GERMLINE_SINGLESAMPLE
,GERMLINE_MULTISAMPLE
,GERMLINE_TRIO
,SOMATIC_SINGLESAMPLE
,SOMATIC_PAIR
-
The
##SAMPLE=
header specifies the analyzed sample name(s) and can contain additional annotations. It can be present several times. -
The
##DESCRIPTION=
header describes columns. It can be present several times. -
The
##FILTER=
header describes entries in thefilter
column. It can be present several times.
After the meta data header line, the main header line and the variant lines follow:
#chr start end ref obs genotype filter quality gene variant_type coding_and_splicing RepeatMasker dbSNP 1000g ExAC ExAC_hom Kaviar phyloP Sift MetaLR PolyPhen2 FATHMM CADD OMIM ClinVar HGMD COSMIC ihdb_allsys_hom ihdb_allsys_het classification classification_comment validated comment gene_info
chr1 27682481 27682481 G A het off-target QUAL=2181;DP=169;AF=0.51;MQM=60 MAP3K6 intron MAP3K6:NM_004672.4:intron:MODIFIER:exon27/28:c.3711+36C>T:,MAP3K6:NM_001297609.1:intron:MODIFIER:exon26/27:c.3687+36C>T: rs12569127 0.1903 0.2656 4554/3529/231 0.2588 95 396 MAP3K6 (inh=n/a pLI=0.00)
...