I'm a little confused on the format of phased variants in a VCF file. I was under the assumption that
A|B is equal to
Paternal Haplotype | Maternal Haplotype but I believe it's
Haplotype Block A | Haplotype Block B.
So in the case of
KID DAD MOM 0|1 0|1 0|1
How does one determine the parent of origin for the derived allele?