A How Many HLA-DR α:β Combinations Can Be Made by an Individual

Essay

A. How many HLA-DR α:β combinations can be made by an individual who is heterozygous at all HLA-DRβ loci, inherits the DRβ haplotype DRB1 from their mother, the DRβ haplotype DRB1, DRB4 from their father, and also inherits different allelic forms of DRA from each parent?
B. Repeat this exercise given the same information except that the maternal DRβ haplotype is DRB1, DRB3.