B(x) - A New Sub-Group of the Blood Group B

Three Cases of Weak B in an Indian Family

“…The antigen appears to be inherited by an allele of B at ABO locus. These cases closely resemble the ones described by Levine et al [8], Mäkelä and Mäkelä [10] and Yokoyama et al [17]. The cells reacted more strongly with immune anti-B and anti-A+B (group 0) sera.…”

“…Reactions of the red cells of the three cases described here are in many respects similar to the ones described by Mäkelä and Mäkelä as weak B, Levine et al [8] as Bw and Yokoyama et al [17] as Bx, there being some difference in the strength of the B antigen on the red cells. In contrast to the cases reported by Yokoyama et al…”

“…Eluates prepared from cells of our weak B cases showed high anti-B activity, while Yokoyama et al [17] reported very weak anti-B activity and Mäkelä and Mäkelä [10] reported good anti-B activity from their cases. Contrary to Levine et al [8] we found that the release of anti-B from that of weak B cells of our series, though good, was less than the release of anti-B from normal B cells treated with the same serum.…”

“…The weak B antigen can either be due to a new allele at the ABO locus or due to suppression of B antigen by some rare suppressor gene as is postulated for some weak forms of A antigen. Suppression of B antigen due to homozygous recessive suppressor gene is excluded since it is transmitted in one child, R. A., from her father, A. J., and in that case the rare suppressor gene should be present in the [10] [17] mother, an event which is highly unlikely in random population. Thus it is most likely due to a new allele of B at the ABO locus and is inherited as Mendelian dominant or possibly due to a suppressor gene acting in heterozygous condition.…”

“…It is only during the last few years that variants of B have been noticed (Mäkelä and Mäkelä [10], Moullec et al [11], Levine et al [8], Dunsford et al [4], Yokoyama et al [17,18] and Armstrong et al [1]^. We have come across a family with three cases of weak B. Yokoyama et al [18] in their recent review of the subject anticipated the occur rence of such cases in India.…”