Gm and Inv (Km) studies of Melanesian people on the Huon Peninsula in Northeast Papua New Guinea: polymorphism for a Gm1,5,10,11,13,14,17,21,26 Haplotype

IGHG3 G and the pathogenesis of hyperreactive malarious splenomegaly

Hyperreactive malarious splenomegaly is an aberrant response to chronic malarial infection, defined by persistent gross splenomegaly and elevated serum IgM and IgG. The populational and familial patterns of this disorder suggest genetically based, immune incompetence. In Papua New Guinea, the disease occurs among populations characterized by high frequencies of IGHG3 G haplotypes. Elsewhere, the distribution and prevalence of hyperreactive malarious splenomegaly is consistent with the distributions of IGHG3 alleles. Drawing upon this relationship, I suggest that expression of the G3M G phenotype is a necessary precondition for hyperreactive malarious splenomegaly, consistent with the pathogenesis of malaria and the functions of the immune system.

Genetic characterization of Gainj- and Kalam-speaking peoples of Papua New Guinea

The research presented focuses on genetic variation in the Gainj- and Kalam-speaking peoples of highland Papua New Guinea. The primary data are typings at 51 genetic loci observed on 600 individuals who reside in 21 census units, called parishes. These data are augmented by cultural and demographic information that has also been collected. Parish sizes are small, ranging from 20 to about 200 individuals. Direct Western contact with these people has been occurring only for the past three decades. Although Westernization is currently increasing, we find that much of the traditional settlement pattern and mate exchange system is preserved. There are segregating variants at 27 loci. Four rare variants are initially described: NP 4-Kalam, ADA 6-Kalam, PEPA 3-Kalam, and FUM 2-Kalam. We find evidence for a new Gm haplotype, a;-, that is recessive to all other Gm haplotypes. It occurs at a high enough frequency, f(a;-) = 0.119, to be considered a "private polymorphism." Average per locus heterozygosity is estimated to be 0.053. This value is not statistically different from levels observed on two modern urban populations. Thus, there is no evidence for a reduced level of genetic variation in these people, despite small parish sizes and a relatively unacculturated social structure.