Indigenous Australian genomes show deep structure and rich novel variation.

The Indigenous peoples of Australia have a rich linguistic and cultural history. How this relates to genetic diversity remains largely unknown because of their limited engagement with genomic studies. Here we analyse the genomes of 159 individuals from four remote Indigenous communities, including people who speak a language (Tiwi) not from the most widespread family (Pama-Nyungan). This large collection of Indigenous Australian genomes was made possible by careful community engagement and consultation. We observe exceptionally strong population structure across Australia, driven by divergence times between communities of 26,000-35,000 years ago and long-term low but stable effective population sizes. This demographic history, including early divergence from Papua New Guinean (47,000 years ago) and Eurasian groups1, has generated the highest proportion of previously undescribed genetic variation seen outside Africa and the most extended homozygosity compared with global samples. A substantial proportion of this variation is not observed in global reference panels or clinical datasets, and variation with predicted functional consequence is more likely to be homozygous than in other populations, with consequent implications for medical genomics2. Our results show that Indigenous Australians are not a single homogeneous genetic group and their genetic relationship with the peoples of New Guinea is not uniform. These patterns imply that the full breadth of Indigenous Australian genetic diversity remains uncharacterized, potentially limiting genomic medicine and equitable healthcare for Indigenous Australians.

Genomic insights into the peopling of the Southwest Pacific.

The appearance of people associated with the Lapita culture in the South Pacific around 3,000 years ago marked the beginning of the last major human dispersal to unpopulated lands. However, the relationship of these pioneers to the long-established Papuan people of the New Guinea region is unclear. Here we present genome-wide ancient DNA data from three individuals from Vanuatu (about 3,100-2,700 years before present) and one from Tonga (about 2,700-2,300 years before present), and analyse them with data from 778 present-day East Asians and Oceanians. Today, indigenous people of the South Pacific harbour a mixture of ancestry from Papuans and a population of East Asian origin that no longer exists in unmixed form, but is a match to the ancient individuals. Most analyses have interpreted the minimum of twenty-five per cent Papuan ancestry in the region today as evidence that the first humans to reach Remote Oceania, including Polynesia, were derived from population mixtures near New Guinea, before their further expansion into Remote Oceania. However, our finding that the ancient individuals had little to no Papuan ancestry implies that later human population movements spread Papuan ancestry through the South Pacific after the first peopling of the islands.

Genetic evidence for two founding populations of the Americas.

Genetic studies have consistently indicated a single common origin of Native American groups from Central and South America. However, some morphological studies have suggested a more complex picture, whereby the northeast Asian affinities of present-day Native Americans contrast with a distinctive morphology seen in some of the earliest American skeletons, which share traits with present-day Australasians (indigenous groups in Australia, Melanesia, and island Southeast Asia). Here we analyse genome-wide data to show that some Amazonian Native Americans descend partly from a Native American founding population that carried ancestry more closely related to indigenous Australians, New Guineans and Andaman Islanders than to any present-day Eurasians or Native Americans. This signature is not present to the same extent, or at all, in present-day Northern and Central Americans or in a ∼12,600-year-old Clovis-associated genome, suggesting a more diverse set of founding populations of the Americas than previously accepted.

Infección por Salmonella enterica subespecie salamae en un paciente ecuatoguineano consumidor de carne de tortuga / Salmonella enterica subspecies salamae infection in a patient from Equatorial Guinea associated with consumption of reptile meat

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Mountain pygmies of Western New Guinea: a morphological and molecular approach.

The presence of "pygmy" or pygmoid groups among New Guinea populations has been the object of scientific interest since the end of the nineteenth century. Morphological and molecular data are used here to study western New Guinea population variability, focusing in particular on two pygmoid groups living in the eastern fringe highlands of Papua: the Una and the Ketengban. Various kinds of anthropometric data are examined, as well as height, weight, and body mass index, to carry out comparisons with nearby ethnic groups living in the highland and lowland regions. The Ketengban data were also compared with other data recorded 20 years before. The results of previous research on the sequencing of the mitochondrial DNA hypervariable segment 1 region and nuclear DNA nonrecombining Y-chromosome polymorphisms are presented. Both morphological and molecular studies involve adult subjects of both genders, representative of the same ethnic groups and/or geographic regions. The pygmoid groups turn out to be significantly different from all other study groups, due to their small size, as confirmed by analysis of variance, although significant height and weight increments are observed with respect to those previously recorded. However, putative neutral genetic variation estimated from mitochondrial DNA and Y-chromosome markers support a recent shared common history between these pygmoid populations and the other central Papua groups (except for the Dani-Lani). These findings suggest that the short-stature phenotype is an independent secondary adaptation, possibly driven by an iodine-deficient environment, which leaves the potential for further investigations.

Kuru: the old epidemic in a new mirror.

The kuru epidemic lasted almost a century; it started in 1901-1902, reached epidemic proportions in the mid-1950s, and disappeared in the 1990s. Kuru is the prototype member of a group of disorders known as transmissible spongiform encephalopathies (TSEs) or prion diseases. Recent data on the genetics and pathogenesis of TSEs contribute to a better understanding of the documented kuru phenomena, and vice versa, observations made during the kuru epidemic are immensely helpful in understanding the epidemic of variant Creutzfeldt-Jakob disease that is currently developing in Europe. The major goal of this review is to identify and illustrate these points.

Studies on the discontinuous N-oxidation of trimethylamine among Jordanian, Ecuadorian and New Guinean populations.

Whilst the majority of individuals within a British white population are able to convert greater than 90% of their dietary-derived trimethylamine to its N-oxide, outliers exist who show varying degrees of impairment. Such individuals excrete unoxidized trimethylamine in their urine and, if sufficiently compromised, may experience malodour problems (Fish-Odour Syndrome). Little information concerning this polymorphic N-oxidation process is available in other ethnic groups and the present study explores Jordanian, Ecuadorian and New Guinean populations. Subjects with a relative deficiency in N-oxidation were found in all three groups, with 1.7% (2/116) Jordanian, 3.8% (3/8) Ecuadorian and 11.0% (11/100) New Guinean excreting 80% or less of their total trimethylamine as the N-oxide. Two subjects from the Ecuadorian population (4% and 33% total trimethylamine as the N-oxide) exhibited frank trimethylaminuria. These observations suggest that a compromised ability to N-oxidize trimethylamine is detectable in several ethnic groups and that this polymorphic phenomenon may have a widespread existence.

An assessment of acetylator polymorphism and its relevance in Papua New Guinea.

A number of clinically useful drugs such as isoniazid, sulphonamides, procainamide and dapsone are rapidly inactivated and eliminated metabolically by an acetyltransferase enzyme. The rate of elimination of these drugs is dependent upon the level of enzymatic activity, which is known to be genetically determined and exhibits ethnic and geographical variation. The study of acetylation polymorphism therefore is important especially in view of its effect on drug efficacy and toxicity. Limited information is available on the acetylation status of Papua New Guineans. Studies conducted so far have revealed an unusually high frequency of the rapid acetylator phenotype (greater than 90%) in certain populations. This study confirms the previous observations and reviews the world-wide distribution pattern of acetylation polymorphism.

Malaria in southeast Queensland in 1979.

The incidence of malaria in Australia is increasing. With the emergence of strains of Plasmodium falciparum resistant to chloroquine there are new lessons to be learned by laboratory workers in the species diagnosis; by clinicians in the clinical manifestations, the treatment of prophylaxis; and by members of the public about the dangers of malaria, and how it can be prevented. At the same time, old knowledge must not be forgotten. This paper reports some recent experience with a sizeable number of cases.

The clinical significance of lactose intolerance.

Lactose intolerance may give rise to a variety of gastro enterological symptoms depending on the degree of lactase deficiency present. A percentage of patients may be asymtomatic, but the presence of lactose in their diet leads to inadequate absorption of a variety of important nutrients resulting in deficiency disorders or less than optimal weight gain. The increase in migration from southern Europe and of late from Indo-China significantly increases the Australian population likely to be lactase-deficient. Many immigrants keen to adapt to the Australian way of life see milk as a new essential part of their diet. This, accompanied with a lack of basic English as a language, may compound the problem of diagnosis in these patients particularly if the medical practitioner is unaware of the syndrome. The ready availability of lactose-hydrolyzed milk powder as a Pharmaceutical Benefit should allow all patients to gain the nutritional advantage of milk without suffering the complications associated with lactose intolerance.

Iron content of native foods.

Chemical analysis showed that some foods cooked in a cast iron pot gained significantly in iron content. This was particularly so for rice and green vegetables, but not for the major root staples of Papua New Guinea. It therefore seems unlikely that a campaign to encourage the use of iron pots for cooking would significantly increase the iron content of diets in Papua New Guinea to an extent which would mitigate the high prevalence of iron deficiency.

Natality, fertility and marriage status in Sepik River population of New Guinea.

PIP: The characteristics of a defined population of 16 villages with 3,500 people in the Sepik District of Papua, New Guinea from January 1973 to December 1969 are provided as part of a large longitudinal survey planned to cover a full generation in order to determine the effect on health of contact from a Western civilization with a previousl y isolated Melanesian society. Study results are organized into 2 parts-the first part dealing with live births, stillbirths, fertility, maternal age and age-parity analysis, and the second part presenting findings on social factors such as birth interval, illegitimate births, adoption, widowhood, polygeny and divorce. Study results included the following information: 1) The birth rate was 35 per 1,000. A decrease of 50% in the infant mortality rate during the period of study apparently caused a decline in the birth rate; 2) Fertility was relatively low and substantially less than the biological potential. Late marriage, consequent late age for first children (23), and maintenance of a rigid birth interval (a mean of 3.3 years) accounted for low fertility; 3) A birth interval of less than 1.5 years is met with severe disapproval unless it follows the early death of the previous child; 4) Children are highly valued; illegitimate children are readily abosorbed into the extended family and children are freely adopted from one family to another. The "true" divorce rate (excluding unconsummated arranged marriages) was extremely low.^ieng

Insensitivity of respiratory centre to carbon dioxide in the Enga people of New Guinea.

The ventilatory response to a rising carbon-dioxide (CO2) tension has been determined in healthy New Guinea natives using a new apparatus which was developed for field-work. The response in New Guineans did not vary greatly between individuals, in contrast to the finding in healthy Caucasians. In all twelve New Guinean subjects the indices of response fell in the lowest range of Caucasian response. These findings suggest that genetic and racial factors account for the marked variability of the ventilatory response to CO2 in normal man. It is suggested that inherited insensitivity of the respiratory centre in New Guineans (and in some Caucasians) leads to unusually severe disturbances of blood gases in chronic lung disease. This hypothesis is supported by published data relating arterial PCO2 and the severity of airways obstruction in New Guineans.