Province of origin of hepatitis B surface antigen carriers among blood donors in Port Moresby.

A paper published in the Medical Journal of Australia in 1972 gave a breakdown of Port Moresby blood donors by HBS Ag carrier status and area of origin. It has lately become possible to test whether such geographical subsamples provide reliable evidence of the carrier status in the home areas, and it appears that, except for the Islands provinces, they do not. Traditional lifestyles conduce to the maintenance and spread of the virus, which is much more prevalent in the provinces than in the capital.

The intestinal lactase polymorphism in Papua New Guinea.

Discovery of small numbers of people with the gene for persistence of intestinal lactase into adult life (PL) in several parts of Papua New Guinea (PNG) suggests that sporadic mutation as well as diffusion could account for at least part of its present distribution. The existing hypotheses attempting to account for at least part of its present distribution. The existing hypotheses attempting to account for the distribution of the gene have been applied to the available evidence in PNG populations. The water absorption and linkage disequilibrium hypotheses are possible explanations for selection of the trait; the culture historical and calcium absorption hypotheses seem unlikely, however, to explain the observed frequencies. It seems possible that more intensive study of the properties of the enzyme might reveal a connection with processes other than lactose hydrolysis.

Probable Pendred syndrome on Goodenough Island.

A large kindred from Bwaidoga village in south-eastern Goodenough Island is described, in which occur several cases of what appear to be the Pendred syndrome: deafness associated with goitre. It is possible that deviations from the more usual pattern of the syndrome may be due to its having arisen from a spontaneous mutation, not identical with the mutation seen elsewhere.

A high-frequency albinism variant on the gulf coast of Papua.

An apparently recessively inherited albinism variant characterized by skin tanning, light but not white hair, uniformly pigmented irides varying in colour from hazel to dark brown, slight nystagmus, divergent strabismus, mild hyperkeratosis and only slight or absent photophobia, occurs among the Elema-speaking peoples of the Gulf Province of Papua New Guinea at frequencies indicating that the gene which produces it is polymorphic. It is readily distinguishable from both classical types of albinism, from the "redskin" variant also found in Papua New Guinea, and from the "yellow mutant" albinism of North America. The differences from the African types of "albinoidism" or "partial albinism" are less marked, and it may represent a similar mutation with simply a different distribution of the melanosomes in the two peoples, Allelism, or lack of it, with classical tyrosinase-positive albinism has not been determined.

The Griqua of Campbell, Cape Provice, South Africa.

The Griqua of Campbell in the Cape Province of South Africa are reputed to be descended from an amalgam of Khoi ("Hottentots") with various Caucasoid, Negroid and East Asian elements at the Cape of Good Hope. A stormy history of migration and deprivation has left this small residuum on the edge of the Kalahari Desert. It was hoped that a sero-genetic study of these people, who proudly preserve their identity, might provide further insights into the genetic consitution of their Khoi forebears. Despite the retention of the language of their own, an social mores distinct from of other Mixed populations, they have been shown, however, to have received an appreciable inflow of non-Khoisan genes. This has probably resulted from social factors such as the prestige attaching to Griqua membership and the willingness of the Griqua to assimilate outsiders, combined with the tendency of Campbell Griqua to migrate elsewhere. There are no significant differences between "Griqua" members of the population and those who are not recognized as "Griqua."

Serogenetic studies on the Kavango peoples of South West Africa.

The closely interrelated matrilineal Kavango peoples of the far north-east of South West Africa are probably the least known inhabitants of that country. Their traditional historical and cultural affinities appear to be with the peoples of southern Angola and south-western Zambia; the suggested relationships with the Ambo further west are not linguistically tenable, though there is evidence of gene exchange. The Kavango comprise the Kwangali, the Mbunza, whom they are in process of absorbing, the Sambyu, the Gciriku, the Mbukushu and the Kwengo. The last-named of these have hitherto been accounted "Black Bushmen", but the serogenetic investigation of these peoples described here discloses that the affinities of the Kwengo are with their neighbours the Mbukushu, and they must therefore be accounted Negro rather than San. Genetic distance calculations are compatible with traditional history and hence with the suggestion that all these peoples share a fairly recent common origin.

Highland and lowland populations of Lesotho.

It has not been possible to demonstrate significant sero-genetic differences between lowland and highland Sotho populations; the differences which do exist may well be attributable to random genetic drift. The study shows that the Sotho have received an appreciable genetic contribution from the San they have absorbed but their sero-genetic profile remains eminently Negro. A low frequency of the PTC non-taster allele was found (t = 0.142 +/- 0.029) as was the overall frequency for colour blindness (cb = 0.013 +/- 0.009).

Serogenetic studies on the Kamea (Kapau) Anga of the interior of the Gulf Province of Papua.

Though the Anga or Kukukuku of Papua New Guinea have been the subjects of occasional human biological investigations in the past, these have all been directed from the north, and their largest division, the Kamea or Kapau, who occupy the southeastern half of their territory, have been substantially neglected. The present paper describes the results of sero-genetic investigations of a small sample of Kamea, who are shown to resemble their fellow-Anga closely in the distribution of their genetic markers, though there are indications that the Kamea have received some gene flow from the south. On the whole, though, the relative uniformity of gene marker distribution throughout the Anga points strongly to their common origin, and the paucity of signs of immigrant gene flow from their neighbours, the victims of their raids, tends to confirm that they practised cannibalism rather than the genetic incorporation of captives.

Significance of detection of extra metacentric microchromosome in amniotic cell culture.

A metacentric bisatellited microchromosome was detected in all metaphases from an amniotic culture performed because of maternal age. A wide-ranging survey of the literature failed to disclose any consistent anomaly associated with such a marker, but did reveal that the clinical picture of patients manifesting it could range from complete normality through mental retardation to a variety of deformities. The parents elected for termination, and the only deformity detected in the abortus was fixed talipes equinovarus. The implications of the finding of this marker chromosome on amniocentesis, believed to be reported for the first time here, are discussed particularly in the context of genetic counselling.

An XXYY male presenting with aggression: a case report.

An abnormally tall 21-year-old Caucasoid male was referred for psychiatric assessment for pathological aggression and mental subnormality. He showed many of the phenotypic features of Klinefelter's syndrome. Cytogenetic studies revealed a 48,XXYY karyotype. The significance of the association of this karyotype with aggressive behaviour is discussed.

Sero-genetic studies on the Dama of South West Africa.

The Dama of South West Africa are a Negroid people living as a reproductive isolate in the desert and semi-desert areas of the north-west of the country. Until recent times a large proportion of them were held in bondage by the Khoikhoi (Hottentot) Nama, while the rest lived as hunter-gatherers in the mountains. This study and the work of Knussmann and Knussmann indicate that they are a Negro people, which probably has been cut off over a period from contact with other Negroes. They have received very little genetic contribution from the Khoikhoi or the San (Bushmen). The results of this investigation of 24 blood genetic marker systems in a carefully selected random sample of Dama support these conclusions.