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1.  MBL2 Variations and Malaria Susceptibility in Indian Populations 
Infection and Immunity  2014;82(1):52-61.
Human mannose-binding lectin (MBL) encoded by the MBL2 gene is a pattern recognition protein and has been associated with many infectious diseases, including malaria. We sought to investigate the contribution of functional MBL2 gene variations to Plasmodium falciparum malaria in well-defined cases and in matched controls. We resequenced the 8.7 kb of the entire MBL2 gene in 434 individuals clinically classified with malaria from regions of India where malaria is endemic. The study cohort included 176 patients with severe malaria, 101 patients with mild malaria, and 157 ethnically matched asymptomatic individuals. In addition, 830 individuals from 32 socially, linguistically, and geographically diverse endogamous populations of India were investigated for the distribution of functional MBL2 variants. The MBL2 −221C (X) allelic variant is associated with increased risk of malaria (mild malaria odds ratio [OR] = 1.9, corrected P value [PCorr] = 0.0036; severe malaria OR = 1.6, PCorr = 0.02). The exon1 variants MBL2*B (severe malaria OR = 2.1, PCorr = 0.036; mild versus severe malaria OR = 2.5, PCorr = 0.039) and MBL2*C (mild versus severe malaria OR = 5.4, PCorr = 0.045) increased the odds of having malaria. The exon1 MBL2*D/*B/*C variant increased the risk for severe malaria (OR = 3.4, PCorr = 0.000045). The frequencies of low MBL haplotypes were significantly higher in severe malaria (14.2%) compared to mild malaria (7.9%) and asymptomatic (3.8%). The MBL2*LYPA haplotypes confer protection, whereas MBL2*LXPA increases the malaria risk. Our findings in Indian populations demonstrate that MBL2 functional variants are strongly associated with malaria and infection severity.
PMCID: PMC3911836  PMID: 24126531
2.  Variations in ncRNA gene LOC284889 and MIF-794CATT repeats are associated with malaria susceptibility in Indian populations 
Malaria Journal  2013;12:345.
There are increasing evidences on the role of non-coding RNA (ncRNA) as key regulator of cellular homeostasis. LOC284889 is an uncharacterized ncRNA gene on reverse strand to MIF mapped to 22q11.23. MIF, a lymphokine, regulates innate immune response by up-regulating the expression of TLR4, suppressing the p53 activity and has been shown to be involved in malaria pathogenesis.
In this study, the possible effect of MIF variations on malaria susceptibility was investigated by re-sequencing the complete MIF gene along with 1 kb each of 5′ and 3′ region in 425 individuals from malaria endemic regions of the Orissa and Chhattisgarh states of India. The subjects comprised of 160 cases of severe malaria, 101 of mild malaria and 164 ethnically matched asymptomatic controls. Data were statistically compared between cases and controls for their possible association with Plasmodium falciparum malarial outcome.
It is the first study, which shows that the allele A (rs34383331T > A) in ncRNA is significantly associated with increased risk to P. falciparum malaria [severe: OR = 2.08, p = 0.002 and mild: OR = 2.09, P = 0.005]. In addition, it has been observed that the higher MIF-794CATT repeats (>5) increases malaria risk (OR = 1.61, p = 0.01). Further, diplotype (MIF-794CATT and rs34383331T > A) 5 T confers protection to severe malaria (OR = 0.55, p = 0.002) while 6A (OR = 3.07, p = 0.001) increases malaria risk.
These findings support the involvement of ncRNA in malarial pathogenesis and further emphasize the complex genetic regulation of malaria outcome. In addition, the study shows that the higher MIF-794CATT repeats (>5) is a risk factor for severe malaria. The study would help in identifying people who are at higher risk to malaria and adapt strategies for prevention and treatment.
PMCID: PMC3849407  PMID: 24066864
Malaria; MIF; Non-coding RNA; Polymorphism; Indian populations; Diplotype
3.  Screening for the sickle cell gene in Chhattisgarh state, India: an approach to a major public health problem 
Journal of community genetics  2011;2(3):147-151.
The aim of this study is to determine the feasibility of large-scale population screening for the sickle cell gene in high risk areas with limited resources. A programme designed to detect the sickle cell trait and sickle cell disease has screened 359,823 subjects among 2,087 (99.7%) of the villages in Raipur District, Chhattisgarh State, India between October 2007 and June 2010. Children aged 3–15 years were initially screened in the villages by solubility tests on fingerprick samples. Venipuncture was performed on subjects with positive solubility tests, and the samples were transferred to Raipur Medical College for alkaline haemoglobin electrophoresis. The sickle cell trait occurred in 33,467 (9.30%) and an SS phenotype in 747 (0.21%). The gene frequencies were not in Hardy–Weinberg equilibrium most likely due to a deficiency of the SS phenotype failing to enter the sampled population from either sickness or early death. Subjects with abnormal haemoglobin genotypes may factor this information into decisions regarding marriage and avoid the risks of having children with sickle cell disease. The techniques described may be a model for other developing societies with limited resources.
PMCID: PMC3186031  PMID: 22109821
Population screening; Sickle cell trait; Sickle cell disease; India
4.  IL-4 Haplotype -590T, -34T and Intron-3 VNTR R2 Is Associated with Reduced Malaria Risk among Ancestral Indian Tribal Populations 
PLoS ONE  2012;7(10):e48136.
Interleukin 4 (IL-4) is an anti-inflammatory cytokine, which regulates balance between TH1 and TH2 immune response, immunoglobulin class switching and humoral immunity. Polymorphisms in this gene have been reported to affect the risk of infectious and autoimmune diseases.
We have analyzed three regulatory IL-4 polymorphisms; -590C>T, -34C>T and 70 bp intron-3 VNTR, in 4216 individuals; including: (1) 430 ethnically matched case-control groups (173 severe malaria, 101 mild malaria and 156 asymptomatic); (2) 3452 individuals from 76 linguistically and geographically distinct endogamous populations of India, and (3) 334 individuals with different ancestry from outside India (84 Brazilian, 104 Syrian, and 146 Vietnamese).
The -590T, -34T and intron-3 VNTR R2 alleles were found to be associated with reduced malaria risk (P<0.001 for -590C>T and -34C>T, and P = 0.003 for VNTR). These three alleles were in strong LD (r2>0.75) and the TTR2 (-590T, -34T and intron-3 VNTR R2) haplotype appeared to be a susceptibility factor for malaria (P = 0.009, OR = 0.552, 95% CI = 0.356 –0.854). Allele and genotype frequencies differ significantly between caste, nomadic, tribe and ancestral tribal populations (ATP). The distribution of protective haplotype TTR2 was found to be significant (χ23 = 182.95, p-value <0.001), which is highest in ATP (40.5%); intermediate in tribes (33%); and lowest in caste (17.8%) and nomadic (21.6%).
Our study suggests that the IL-4 polymorphisms regulate host susceptibility to malaria and disease progression. TTR2 haplotype, which gives protection against malaria, is high among ATPs. Since they inhabited in isolation and mainly practice hunter-gatherer lifestyles and exposed to various parasites, IL-4 TTR2 haplotype might be under positive selection.
PMCID: PMC3480467  PMID: 23110190

Results 1-4 (4)