##fileformat=VCFv4.2
##contig=<ID=chr1,length=1000000>
##FORMAT=<ID=GT,Number=1,Type=String,Description="Genotype">
#CHROM	POS	ID	REF	ALT	QUAL	FILTER	INFO	FORMAT	S1	S2
chr1	100	rs1	A	T	.	PASS	.	GT	0/0	0/1
chr1	200	rs2	G	C	.	PASS	.	GT	0/1	1/1
chr1	300	rs3	C	A	.	PASS	.	GT	1/1	0/0
