A population genetic survey of the haptoglobin polymorphism in Melanesians by DNA analysis

We have determined the haptoglobin (Hp) genotypes of 831 Melanesians from Vanuatu, Papua New Guinea, and New Caledonia by Southern blot analysis of DNA extracted from umbilical cord and peripheral blood samples. There was complete agreement between these genotypes and the protein phenotype in cases where both were determined, and genotyping was possible in cases where no serum haptoglobins were measurable. Subtyping of Hp1 alleles using restriction enzymes showed that Melanesians, like Mongoloids and Australian Aboriginals, have only the Hp1S allele. Three cases of Hp Johnson were found in Vanuatu, and further restriction mapping supported a partial gene triplication model for the structure of this variant. We also report a new common BclI restriction enzyme polymorphism upstream of the Hp1 gene. The advantages of using DNA for haptoglobin typing are discussed.