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

Genetic polymorphism analysis among nine endogamous population groups of Maharashtra, India

This paper is a part of the genetic study of the people of Assam (eastern India), initiated by the Anthropometry and Human Genetics Unit, Indian Statistical Institute, Calcutta, India, and the Dept. of Human Biology/Physical Anthropology, University of Bremen, W. Germany. The results of 1. allele distribution of five red cell enzyme polymorphisms in ten Assamese populations, 2. heterogeneity of allele frequencies and extent of gene differentiation among these populations, and 3. standard genetic distances are presented here. A total of 1024 blood samples was screened for aP, E D, AK, ADA and LDH enzyme systems for Brahmins, Kalitas, Kaibartas, Rajbanshis, Muslims, Ahoms, Chutiyas, Kacharis, Karbis (Mikirs) and Sonowals, of which the latter three are tribes. The gene diversity (FST) is smallest (0.0035) for pa and highest (0.1604) for HbE. The total FST value (0.0399 +/- 0.0141) appears to be statistically significant. From distance analysis two major clusters with sub-clusters in each are visible, which are in conformity with the ethnohistory of these populations.

Genetic heterogeneity and population structure in eastern India: red cell enzyme variability in ten Assamese populations.

The four types of genetic variants of lactate dehydrogenase (LDH) found so far in the Indian populations surveyed by starch-gel electrophoresis of haemolysates are described, pointing out their characteristic features. Two of these variant types, namely, ‘Calcutta-1’ and ‘Madras-1, were reported earlier. The other two discovered subsequently and named trivially as ‘Calcutta-2’ and ‘Delhi-1 are now reported for the first time. A comparison between the four LDH variants found in India and those by others outside India has also been drawn.

Four Types of Genetic Variants of LDH Found in India

Incidence of colourblindness among 1501 (945 males and 656 females) persons belonging to four nomadic Mendelian isolates, the Nandiwallas of Maharashtra, India, has been reported. Out of the four groups, three lacked the gene for colourblindness, while in one group the incidence was rather low (0·3 per cent). Our findings support the differential selection hypothesis for this loci of Post (1962) and Pickford (1963). 110 families with 334 children were examined for the inheritance of this trait. All matings except one were of the type normal × normal and produced all normal children; the one family of the type father colourblind × normal mother, also had all the six children with normal colour vision. The implications of the loss of the colourblind gene has been discussed in the light of nomadic way of the Nandiwallas, and also of their small effective population sizes.

/pdf/incidence-of-colourblindness-among-four-endogamous-nomadic-3cuhy460ij.pdf

Incidence of colourblindness among four endogamous nomadic groups: an example of natural selection

In order to test the hypothesis of a major gene effect on absolute total finger ridge count (ATFRC), the nature of relationship between mean ATFRC and its variability was evaluated in a series of 47 population samples from India. Regression analysis showed that both the standard deviation and the coefficient of variation are significantly related to mean ATFRC, and about 35% of the variation in ATFRC is explained by the dependent variable coefficent of variation. These results support the hypothesis of a major gene effect on the trait ATFRC.

Kailash C. Malhotra

Papers

Genetic polymorphism analysis among nine endogamous population groups of Maharashtra, India

Genetic heterogeneity and population structure in eastern India: red cell enzyme variability in ten Assamese populations.

Four Types of Genetic Variants of LDH Found in India

Incidence of colourblindness among four endogamous nomadic groups: an example of natural selection

Genetic Significance of the relationship between absolute total finger ridge count and its variability