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

The heritability of sole pattern ridge counts was examined in two family studies of endogamous castes from peninsular India. The phenotypes included ridge counts for each of the eight configurational areas separately, all areas combined, and only distal areas combined. Differences in heritability estimates were found between populations as well as among the individual configurational areas. Although some ridge counts do not show familial resemblance, others appear to be moderately heritable. Estimates of h2 range from 0.36 to 0.63 in one family series and from 0.22 to 0.51 in the other. In addition, significant uterine environmental effects were detected in one family series but not in the other.

Resolution of genetic and uterine environmental effects in a family study of new dermatoglyphic measure: sole pattern ridge counts.

Red cell hemolysates from 1,004 persons belonging to 14 population groups drawn from four South Indian states, Andhra Pradesh, Tamil Nadu, Karnataka, and Kerala, were tested for PGM1 subtypes. The groups are characterized by a high frequency of phenotype 1+1+ (range 36.98-71.64%) and the allele 1+ (range 60-79%). The groups exhibit marked heterogeneity for PGM1 locus. The results show a clear demarcation between tribes and Brahmin groups.

PGM1 subtype polymorphism in 14 endogamous Dravidian-speaking populations of South India.

Serum samples from eight endogamous Indian tribal populations of Madhya Pradesh (Dhurwa, Halba, Bhatra, Muria, Maria) and Orissa (Deshia Khond, Binjhal, Kisan) with a total of n=731 unrelated individuals were typed for G1M (1,2,3,17), G3M (5,10,11,13,14,15,16,21,26), and KM (1). In seven of these populations five different GM haplotypes were found:GM*1,17;21,26; GM*1,17;10,11,13,15,16; GM*1,2,17;21,26; GM*1,3;5,10,11,13,14,26; andGM*3;5,10,11,13,14,26. In the Kisan sample the haplotypeGM*1,2,17; 21,26 is absent. The intergroup variability in the distribution of these haplotypes is considerable and statistically highly significant. The reasons for that can be attributed to the ethnohistory and to the genetic isolation of these eight endogamous tribal populations. The GM haplotype distribution pattern of all these groups is quite different from that of the non-tribal populations of India, whereas it is in good agreement with that of the so far tested other tribal populations from India. This can be explained by different origin and history of the Indian tribal and non-tribal populations. In the KM system, too, remarkable variability is seen in the distribution of phenotype and allele frequencies among the eight tribal populations under study.

/pdf/gm-and-km-allotypes-in-eight-tribal-populations-of-madyha-3zbckg6fhv.pdf

GM and KM allotypes in eight tribal populations of Madyha Pradesh and Orissa, India.

Genetic variants of lactate dehydrogenase in the Dhangars of Maharashtra, India.

In this paper the effect of age, Hb types and G-6-PD deficiency on height, weight and skinfold thickness among 1720 subjects belonging to Nava-Budha, Maratha and a mixed Scheduled caste of Maharashtra, India, have been examined using two models of analysis of variance. In the first model the factors used for explaining the variation are communities, age, sex, Hb types based on the total sample. In the second model another factor, G-6-PD deficiency, was introduced and only the male sample (n = 852) was considered. The age groups (assessed), sex and communities contribute highly significantly to the variation in weight. Variation in communities, age and sex is highly significant for variations in height and the three skinfold measurements. The effect of variation in Hb types is more than random for height and significant for biceps and triceps thicknesses. G-6-PD deficiency causes significant variation in height and the three skinfold measurements.

Kailash C. Malhotra

Papers

Resolution of genetic and uterine environmental effects in a family study of new dermatoglyphic measure: sole pattern ridge counts.

PGM1 subtype polymorphism in 14 endogamous Dravidian-speaking populations of South India.

GM and KM allotypes in eight tribal populations of Madyha Pradesh and Orissa, India.

Genetic variants of lactate dehydrogenase in the Dhangars of Maharashtra, India.

Effects of Hb types and G-6-PD deficiency on height, weight and skinfolds: a study on Indian population.