FURTHER INVESTIGATION OF THE COLTON BLOOD CROUP IN THE JAPANESE - A LOW COB FREQUENCY AND ITS INDEPENDENCE FROM THE DIEGO BLOOD-GROUP

In testing additional 4,000 blood samples from unrelated Japanese in and around Tokyo 18 (0.45%) were found to be phenotype Co(a+b+), from which the allele frequencies were estimated at Coa: 0.998 and Cob: 0.002. It was confirmed that the Cob frequency in the Japanese is lower by far than in Caucasians. In a family study, independent segregation of the Colton from the Diego blood group system was shown.