Table 1.
ABO blood group subtype alleles (A) and secretor status (B) among pancreatic cancer cases and nested controls in 12 prospective cohort studies*
| (A) | Cases No. (%) | Controls No. (%) | rs505922 | rs8176746 | rs8176704 | rs574347 |
|---|---|---|---|---|---|---|
| No. of participants | 1533 | 1582 | ||||
|
| ||||||
| A blood group alleles | 943 (31) | 847 (27) | ||||
| A1 alleles | 729 (77) | 611 (72) | C | C | G | T |
| A2 alleles | 214 (23) | 236 (28) | C | C | A | T |
|
| ||||||
| O blood group alleles† | 1773 (58) | 2018 (64) | ||||
| O01 alleles | 1108 (63) | 1268 (63) | T | C | G | T |
| O02 alleles | 643 (37) | 733 (37) | T | C | G | C |
|
| ||||||
| B blood group alleles | 350 (11) | 299 (9) | C | A | G | T |
| (B) | Cases No. (%) | Controls No. (%) | rs601338 |
|---|---|---|---|
| Secretor status‡ | |||
| Secretor | 1103 (81) | 1145 (79) | G/G or G/A |
| Non-secretor | 261 (19) | 297 (21) | A/A |
Single nucleotide polymorphism (SNP) data collected in the PanScan genome-wide association study were used to define blood group subtype alleles and secretor phenotype. As shown, the single nucleotide changes at rs505922, rs8176746, rs8176704, rs574347, and rs601338 were used to mark the relevant alleles.
The number of O01 and O02 alleles do not sum to the number of O alleles, as blood group O subtype could not be accurately imputed for thirty-nine O alleles.
Secretor status is recessive, such that two non-secretor alleles are necessary to manifest the non-secretor phenotype. Secretor status was successfully imputed for 2,806 of the 2,840 White subjects.