P. B. Booth

Selective depression of blood group antigens associated with hereditary ovalocytosis among melanesians.

Abstract. Recessively inherited ovalocytosis in coastal Melanesians is associated with widespread, but selective, depression of blood group antigens in homozygotes, who comprise about 15% of these populations. It is suggested that a membrane anomaly exists, and that the series of depressed determinants all depend, for their full expression, upon the same membrane component(s), the proper synthesis of which is being genetically affected. Affected antigens would thus be associated by position and/or structure.

The Gerbich blood group system, especially in Melanesians.

Abstract. Investigations of the Gerbich blood group system in Melanesians of Papua/ New Guinea are described. Over 50% of members of certain population groups are Gerbich negative, and anti‐Gea (‘naturally‐occurring’) is present in about 10% of Ge (a‐) people. The distribution of populations with high Ge (a‐) incidence is not explicable at present.

A "new" blood group antigen associated with S and s.

Abstract. The serum of a Papuan blood donor contains an antibody to a previously unreported red cell antigen, provisionally called Z, and closely associated with S or s. In both European and Melanesian populations Z is more common than S, because S‐positive bloods rarely lack Z, while S‐negative bloods not uncommonly possess it. Z is inherited as a dominant character.

Two Melanesian Antisera Reacting with SsU Components

Abstract. Two different Melanesian antibodies demonstrated, by blocking tests and their reaction patterns, steric interaction of S, s and U components. The antigen (s) detected, designated Ux and Uz, may represent differing conformations, genetically determined, of certain U, S and s structures.

A Second Example of Anti-Ge1, and Some Observations on Gerbich Subgroups

Abstract. A second example of anti‐Gel has been identified. The Gerbich subgrouping of certain Melanesian populations has shown that not all subjects who react weakly with anti‐Gel, 2 or anti‐Gel, 2, 3 lack Gel specificity. It is suggested that Gel, ‐2 people may exist in New Guinea.

Variations of H, A and B antigen strengths among Melanesians.

Abstract. Melanesians of groups O, A1 and B all show greater variation of H antigen strength than do Caucasians. This is least marked in O bloods. Although the average H content of Melanesian and Caucasian samples did not differ significantly, 10% of O and over 20% of A1 and B bloods from coastal Austronesian speakers had higher H than was found among Caucasians. There is evidence that some non‐Austronesian populations in New Guinea have twice this incidence of A1 high H.

H, A and A1 Reactivity in Two Polynesian Groups

Abstract. Polynesian O bloods from Samoans and Tokelau Islanders have the same mean H reactivity as Caucasian, and their A, bloods the same A1 content. However, Polynesian A1 bloods have significantly greater H reactivity than Caucasian, and the Tokelau Tslanders also showed enhanced A and IT. It is suggested that the Polynesian AHI molecular conformation must differ from the Caucasian pattern, providing an arrangement of antigen sites more favourable to some antigen‐antibody reactions.

The Non‐Identity of Anti‐NA and Anti‐N in the Serum of an MN Persan

Abstract. The anti‐N in the serum of an MN person is not anti‐NA, and her red cells are MNA.