A New Variant in the ABO Blood Group System: B_h

Abstract

Summary. The authors describe an assumed but hitherto undiscovered variant of incomplete ‘Bombay’ phenotype, designated as Bh, with partial suppression of the B antigen. The erythrocytes contain a very weak B antigen, at quantitative level B20; they are H‐negative and Lea‐positive. The serum contains anti‐A, anti‐B and anti‐H antibodies. The patient is a secretor of Lea and a non‐secretor of ABH. The quantitative and immunogenetic properties of the variant are discussed. It is supposed that the variant is the effect of the gene combinations Hxh, or HxHx at the Hh locus. We wish to thank the physicians attending the patient K. M., Dr. V. Kluge from Tatranská Kotlina and Dr. L. Dráč; from Vel'ký. Šariš for assistance in obtaining the necessary blood samples.

New Variants in the ABOH Blood Group System due to Interaction of Recessive Genes Controlling the Formation of H Antigen in Erythrocytes: the 'Bombay'-Like Phenotypes O(Hm), O^B(Hm), O^AB(Hm)

“…As far as is known recessive suppression of blood group manifesta tion may be caused either by the homozygous combination hh and by the weaker alleles or partial genes at the H locus (H2... H3... Hx [1,9]), or by the yy genes [13,15]. The former results in a true 'Bombay' phenotype expressed to a greater or lesser degree (Ar [9] and Bh [1] respectively), and the latter in the suppression of the A phenotype in erythrocytes only (Am [15] and AmB [13] respective ly).…”

“…The former results in a true 'Bombay' phenotype expressed to a greater or lesser degree (Ar [9] and Bh [1] respectively), and the latter in the suppression of the A phenotype in erythrocytes only (Am [15] and AmB [13] respective ly). As carriers of Am variants (also Bm, [13]) have a normal H antigen it is clear that the homozygous combination yy (and a similar but still undiscovered combination of corresponding recessive genes for Bm) does not influence the H/h locus.…”

“…the Le and Se genes. It is clear that this control is exercised not only by the alleles H and h, but also by other alleles weaker than H or Hv and/or stronger than h [1,9]. …”