Allele Frequency of ABO Blood Group Antigen and the Risk of Esophageal Cancer

Table 5

Hardy-Weinberg model for ABO blood group.

Phenotype (blood group)	Genotype	Phenotypic frequency	Genotypic frequency	Expected frequency
A	AA + AO	𝑛A	𝑛AA + 𝑛AO	𝑝^2 + 2pr
B	BB + BO	𝑛B	𝑛BB + 𝑛BO	𝑞^2 + 2qr
AB	AB	𝑛AB	𝑛AB	2pq
O	OO	𝑛O	𝑛OO	𝑟^2

Hardy-Weinberg equation for ABO blood group is as follows:
𝑝 + 𝑞 + 𝑟 = 1,
𝑝² + 𝑞² + 𝑟² + 2pq + 2pr + 2qr = 1.