Advanced Statistical Methods in Biometric Research.

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(12)61229-X.pdf

Global epidemiology of sickle haemoglobin in neonates: a contemporary geostatistical model-based map and population estimates.

Glucose-6-phosphate deficiency is the most prevalent enzyme deficiency, with an estimated 400 million people affected worldwide. This inherited deficiency causes neonatal hyperbilirubinemia and chronic hemolytic anemia. Although most affected individuals are asymptomatic, exposure to oxidative stressors such as certain drugs or infection, can elicit acute hemolysis. To characterize the global prevalence of G6PD deficiency, we conducted a systematic review of the G6PD deficiency literature, drawing studies from various databases, including MEDLINE/Pubmed and Biosis. Selected studies included cross-sectional and longitudinal studies published between 1960 and 2008. Additionally, meta-analytic procedures were employed to assess the degree of heterogeneity amongst prevalence estimates and, where appropriate, pool them. The searches yielded a total of 280 prevalence estimates, corresponding to 88 countries. The highest prevalence rates were reported among Sub-Saharan African countries, even after adjusting for assessment method. Meta-analysis revealed a high degree of heterogeneity for regional and global prevalence estimates. This heterogeneity in reported estimates appeared to be due to differences in G6PD deficiency assessment and diagnostic procedures. The magnitude and variation in global, regional, and country-level prevalence rates of G6PD deficiency are of public health import, particularly in planning programs to improve neonatal health and in the distribution of various medications, especially antimalarial drugs, as G6PD deficiency is most prevalent in malaria-endemic areas.

/pdf/the-global-prevalence-of-glucose-6-phosphate-dehydrogenase-ejdrzw5q9l.pdf

The global prevalence of glucose-6-phosphate dehydrogenase deficiency: a systematic review and meta-analysis.

https://www.bmj.com/content/bmj/1/6059/515.3.full.pdf

Handbook of Enzyme Electrophoresis in Human Genetics

It has been 100 years since the first report of sickle haemoglobin (HbS). More than 50 years ago, it was suggested that the gene responsible for this disorder could reach high frequencies because of resistance conferred against malaria by the heterozygous carrier state. This traditional example of balancing selection is known as the 'malaria hypothesis'. However, the geographical relationship between the transmission intensity of malaria and associated HbS burden has never been formally investigated on a global scale. Here, we use a comprehensive data assembly of HbS allele frequencies to generate the first evidence-based map of the worldwide distribution of the gene in a Bayesian geostatistical framework. We compare this map with the pre-intervention distribution of malaria endemicity, using a novel geostatistical area-mean comparison. We find geographical support for the malaria hypothesis globally; the relationship is relatively strong in Africa but cannot be resolved in the Americas or in Asia.

/pdf/global-distribution-of-the-sickle-cell-gene-and-geographical-53pvwwy722.pdf

Global distribution of the sickle cell gene and geographical confirmation of the malaria hypothesis

Indian society is an agglomeration of several thousand endogamous groups or castes each with a restricted geographical range and a hereditarily determine mode of subsistence. These reproductively isolated castes may be compared to biological species, and the society thought of as a biological community with each caste having its specific ecological niche. In this paper we examine the ecological-niche relationships of castes which are directly dependent on natural resources. Evidence is presented to show that castes living together in the same region had so organized their pattern of resource use as to avoid excessive intercaste competition for limiting resources. Furthermore, territorial division of the total range of the caste regulated intra-caste competition. Hence, a particular plant or animal resource in a given locality was used almost exclusively by a given lineage within a caste generation after generation. This favoured the cultural evolution of traditions ensuring sustainable use of natural resources. This must have contributed significantly to the stability of Indian caste society over several thousand years. The collapse of the base of natural resources and increasing monetarization of the economy has, however, destroyed the earlier complementarity between the different castes and led to increasing conflicts between them in recent years.

/pdf/adaptive-significance-of-the-indian-caste-system-an-1qmp14yc63.pdf

Adaptive significance of the Indian caste system: an ecological perspective

Morphological composition of the people of India

Previous studies have reported a high incidence of hemoglobin E (HbE) in Northeast Indian populations. In the present study 10 endogamous populations of Assam belonging to two racial groups, Caucasoid and Mongoloid, were examined. The frequency of HbE gene (Hb βE) in the Caucasoid caste populations is around 0.1, whereas the gene is highly prevalent in the Mongoloid populations, frequencies ranging between 0.2 and 0.6. Predominance of Hb βE in the Tibeto-Burman speakers is contrary to observations made in Southeast Asia, where an association between Austro-Asiatic speakers and high prevalence of HbE exist. The highest occurrence of the gene in this area, which is on the far end of the proposed centre of distribution in Northern Kampuchea and Northeast Thailand, is also a deviation from the expected pattern of gene distribution. It is speculated that Hb βE in the Tibeto-Burman populations of Assam arose by an independent mutation which contributed to the high frequencies of Hb βE in the Northeast Indian populations.

Hemoglobin E Distribution in Ten Endogamous Population Groups of Assam, India

In spite of the unrelenting advent of modernization involving industrialization and market-oriented land use policies, traditional ecological ethos still survive in many indigenous societies, albeit in much attenuated forms. Based on a series of our past investigations into the traditional resource use norms and associated cultural institutions prevailing in rural Bengal societies, we demonstrate here that a large number of elements of local biodiversity, regardless of their use value, are protected by the local cultural practices. Certain cultural elements (e.g., auguries) may not have any conservation consequences, yet may reflect, in symbolic terms, a collective appreciation of the intrinsic or existence value of life forms, and the basic love and respect for nature. The study suggests that traditional conservation ethics are still capable of protecting much of the country's decimating biodiversity, as long as the local communities have even a minor share in the management of natural resources.

/pdf/conservation-ethos-in-local-traditions-the-west-bengal-3ekixpodnc.pdf

Conservation Ethos in Local Traditions: The West Bengal Heritage

Genetic polymorphisms for six blood groups, three red cell enzymes, three serum proteins, and hemoglobin were examined in sixteen central Indian tribal populations. Nine of the tribes belonged to Orissa, five to Madhya Pradesh, and two to Maharashtra. Eleven tribes spoke the Dravidian language, three Indo-Ayran, and two the language of the Austro-Asiatic families. The population structure of these tribal populations was analyzed at the inter- and intrastate and linguistic levels, using data for 13 genetic systems (38 alleles or haplotypes). Nine of the 13 loci showed significant heterogeneity in the 16 tribes, and the pattern of heterogeneity was also discernible in the different states and in the Dravidian-speaking tribes. As expected, the extent of genetic differentiation or gene diversity was the highest so far reported from central India. The mean FIS and HS for each locus in the different state, linguistic, and total tribal groups were consistently higher than the FST and GST values, respectively, showing that the genetic structure of each tribe is highly influenced by inbreeding. In a genetic affinity analysis by genetic distance the Indo-Aryan and Austro-Asiatic language groups showed little affinity with each other, although there was some tendency toward geographic affinity. The present analysis indicates that, in addition to genetic drift, gene flow, and selection, the genetic structure of the populations of central India is also highly influenced by sociocultural adaptation and inbreeding.

Kailash C. Malhotra

Papers

Adaptive significance of the Indian caste system: an ecological perspective

Morphological composition of the people of India

Hemoglobin E Distribution in Ten Endogamous Population Groups of Assam, India

Conservation Ethos in Local Traditions: The West Bengal Heritage

Population structure and genetic differentiation among 16 tribal populations of central India.