title: Interferon-γ (IFNG) microsatellite repeat and single nucleotide polymorphism haplotypes of IFN-α receptor (IFNAR1) associated with enhanced malaria susceptibility in Indian populations.
abstract: Pro-inflammatory cytokines IFNγ and IFNα function through their cellular receptors IFNγR1 and IFNαR1, respectively to mediate immune processes during malaria infection. A total of 21 SNPs, 2 ins/del polymorphisms and a microsatellite repeat, selected on the basis of their reported association with infectious diseases including malaria in world populations, were analysed for association with Plasmodium falciparum malaria susceptibility in a case-control study with adult patients and ethnically-matched controls drawn from a disease meso- to hyperendemic and a nonendemic region of India. Among the five IFNG SNPs tested, an intron 3 and a 3'UTR SNP associated with disease in the endemic region. In addition, large (CA)n repeats of IFNG intron 1 associated with protection from severe malaria in the endemic region (severe vs. control, odds ratio=0.21, 95% CI=0.08-0.52, P=1.3 × 10(-4)). The TA11CAG haplotype (rs2069705 T/C, rs2430561 A/T, rs3138557 (CA)n, rs2069718 T/C, rs2069727 A/G, rs2069728 G/A) carrying a short CA11 repeat also exhibited very strong association with severe malaria, particularly in the endemic region (severe vs. control, OR=14.56, 95% CI=3.39-85.81, P=3 × 10(-5)). One SNP each from the IFNA8 and IFNA17 of IFNA gene cluster had a protective effect in the non-endemic region but not in the endemic region. A promoter and an intron 2 SNP of IFNAR1 were risk factors for disease and the IFNAR1 haplotype GCCAGG (rs2843710 C/G, rs2850015 C/T, +6993 C/T, rs2243594 A/G, rs1012335 G/C, rs2257167 G/C) carrying both the risk alleles strikingly associated with disease manifestation in the endemic region (severe vs. control, OR=27.14, 95% CI=3.12-1254, P=2 × 10(-5); non-severe vs. control, OR=61.87, 95% CI=10.08-2521, P=1 × 10(-8)). The data indicates dissimilar contribution of cytokine and cytokine receptor variants to disease in populations residing in areas of differential malaria endemicity.
authors.affiliation: Division of Molecular and Structural Biology, CSIR-Central Drug Research Institute, Lucknow, India.
authors.forename: Kanika
authors.initials: K
authors.lastname: Kanchan
authors.affiliation: Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India.
authors.forename: Pankaj
authors.initials: P
authors.lastname: Jha
authors.affiliation: Ispat General Hospital, Rourkela, India.
authors.forename: Sudhanshu S
authors.initials: SS
authors.lastname: Pati
authors.affiliation: Ispat General Hospital, Rourkela, India.
authors.forename: Sanjib
authors.initials: S
authors.lastname: Mohanty
authors.affiliation: Ispat General Hospital, Rourkela, India.
authors.forename: Saroj K
authors.initials: SK
authors.lastname: Mishra
authors.affiliation: National Institute of Malaria Research, New Delhi, India.
authors.forename: Surya K
authors.initials: SK
authors.lastname: Sharma
authors.affiliation: King George's Medical University, Lucknow, India.
authors.forename: Shally
authors.initials: S
authors.lastname: Awasthi
authors.affiliation: King George's Medical University, Lucknow, India.
authors.forename: Vimala
authors.initials: V
authors.lastname: Venkatesh
authors.affiliation: Division of Molecular and Structural Biology, CSIR-Central Drug Research Institute, Lucknow, India. Electronic address: saman.habib@gmail.com.
authors.forename: Saman
authors.initials: S
authors.lastname: Habib
mesh_terms: D000328:Adult; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D007194:India; D016898:Interferon-alpha / Q000235:genetics*; D007371:Interferon-gamma / Q000235:genetics*; D016778:Malaria, Falciparum / Q000235:genetics*; D018895:Microsatellite Repeats; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D053633:Receptor, Interferon alpha-beta / Q000235:genetics*; D017471:Receptors, Interferon / Q000235:genetics*; D044465:White People / Q000235:genetics*; D000096743:Interferon gamma Receptor
chemical_list: D016898:Interferon-alpha; D007371:Interferon-gamma; D053633:Receptor, Interferon alpha-beta; D017471:Receptors, Interferon; D000096743:Interferon gamma Receptor; C507964:IFNAR1 protein, human; C573415:IFNG protein, human
keywords: Cytokine; Haplotypes; Malaria susceptibility; Polymorphisms; Receptor