H-deficient blood groups ( Bombay) of Reunion Island.

Forty-two H-deficient individuals (lacking H antigen on erythrocytes) with anti-H in their sera were found on Reunion Island. A, B, and AB Bombay subjects had small but detectable amounts of A and/or B antigens on erythrocytes. All the H-deficient phenotypes tested were nonsecretors of ABH in their saliva, and one-third were Lewis negative. Fifty-three of the 108 (49%) unaffected members in the 14 Bombay pedigrees analyzed were se/se, showing that the families were selected for the nonsecretor trait, and suggesting that the Bombay probands used to select the families have se/se genotype. In accordance with this concept, all the children from Bombay nonsecretor x unaffected nonsecretor matings were se/se. Segregation of H and Se is compatible with the genetic model proposing that Se and H are closely linked structural genes, and the analysis of the present and previously published Bombay pedigrees strongly supports this model.