Genetic association of rs1520333 G/A polymorphism in the IL7 gene with multiple sclerosis susceptibility in Isfahan population

Investigating the association of polymorphisms of ANKRD55 and MMEL1 with susceptibility to multiple sclerosis in Iranian population

OBJECTIVE

Multiple sclerosis (MS) is an autoimmune neurological disability in which immune cells attack the myelin sheaths that protect nerve fibers. The pathogenesis of the disease involves both complex genetic effects as well as multifaceted gene-environment interactions. In the present study, we examined the association of two Single nucleotide polymorphisms (SNPs) in ANKRD55 (rs6859219) and MMEL (rs3748816) with MS in the Iranian population. ANKRD55 is specifically expressed in human peripheral blood mononuclear cells and CD4 + T cells, while MMEL1is involved in the degradation of both neuropeptides and β-amyloid.

METHODS

In this case-control study, 110 patients with MS and 110 matched healthy controls were enrolled. The Participants were genotyped for ANKRD55 and MMEL1 SNPs using PCR-RFLP and Real-Time TaqMan SNP Genotyping respectively. The results were finally analyzed using SPSS software version 22.

RESULTS

Our results did not show significant differences in allelic frequencies of two SNPs among cases and controls (P-Value >0.05). However, for ANKRD55 (rs6859219), CA genotype was shown to have a protective effect (p = 0.035 and OR = 0.55), while CC genotype was a susceptive genotype to MS (p = 0.036 and OR = 1.8). There was no significant difference in genotypic frequencies of SNP rs3748816 in MMEL1.

CONCLUSION

We could successfully replicate the association of ANKRD55 (rs6859219) with susceptibility to MS in the Iranian population. Our result can provide an insight into better understanding the pathogenesis of MS and also improve the genetic counseling for patients affected with multiple sclerosis in Iran.

Genetic variation in interleukin-7 is associated with a reduced erythropoietic response in Kenyan children infected with Plasmodium falciparum

BACKGROUND

Severe malarial anemia (SMA) is a leading cause of malaria-related morbidity and mortality in children. The genetic factors that influence development of SMA and inefficient erythropoiesis, a central pathogenic feature of SMA, are only partially understood.

METHODS

We performed a pilot Genome-wide Association Study (GWAS) on children with Plasmodium falciparum. The GWAS was performed using the Illumina® Infinium® HD Super Assay in conjunction with Illumina's® Human Omni2.5-8v1 BeadChip (with > 2.45 M markers). Data were analyzed using single SNP logistic regression analysis with an additive model of inheritance controlling for covariates. Results from our pilot global genomics study identified that variation in interleukin (IL)-7 was associated with enhanced risk of SMA. To validate this finding, we investigated the relationship between genotypes and/or haplotypes of two single nucleotide polymorphisms (SNPs) in IL7 [72194 T/C and - 2440 A/G] and susceptibility to both SMA and inefficient erythropoiesis [i.e., reticulocyte production index (RPI) < 2.0 in anemic children (Hb < 11.0 g/dL). Children presenting with P. falciparum malaria (< 3 years, n = 883) were stratified into two groups: Uncomplicated malaria (UM, n = 718) and SMA (n = 165).

RESULTS

Regression modeling, controlling for anemia-related confounders, revealed that carriage of the TC genotype at position 72194 T/C was associated with enhanced susceptibility to inefficient erythropoiesis (OR = 1.90; 95% CI 1.09-3.30; P = 0.02) as was homozygous CC (OR 5.14; 95% CI = 1.20-21.99; P = 0.03). Consistent with this finding, individuals with the CA (72194C/-2440A) haplotype had an increased risk of inefficient erythropoiesis (OR = 1.90; 95% CI = 1.10-3.30; P = 0.02), whereas TA haplotype carriers had marginal protection against inefficient erythropoiesis (OR = 0.24; 95% CI = 0.06-1.21; P = 0.05). These observations were supported by Cochran-Armitage trend test for inefficient erythropoiesis (CA > TA > CG; P < 0.01). Although none of the genotype and/or haplotypic variants were significantly associated with SMA, the direction of the risk profiles were consistent with the erythropoiesis results.

CONCLUSION

Taken together, variation in IL7 is associated with erythropoietic responses in children with falciparum malaria, a central physiological feature contributing to development of SMA.

Panoramic Visualization of Circulating MicroRNAs Across Neurodegenerative Diseases in Humans

Neurodegenerative diseases (NDs) such as Alzheimer’s disease (AD), Parkinson’s disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), and dementia pose one of the greatest health challenges this century. Although these NDs have been looked at as single entities, the underlying molecular mechanisms have never been collectively visualized to date. With the advent of high-throughput genomic and proteomic technologies, we now have the opportunity to visualize these diseases in a whole new perspective, which will provide a clear understanding of the primary and secondary events vital in achieving the final resolution of these diseases guiding us to new treatment strategies to possibly treat these diseases together. We created a knowledge base of all microRNAs known to be differentially expressed in various body fluids of ND patients. We then used several bioinformatic methods to understand the functional intersections and differences between AD, PD, ALS, and MS. These results provide a unique panoramic view of possible functional intersections between AD, PD, MS, and ALS at the level of microRNA and their cognate genes and pathways, along with the entities that unify and separate them. While the microRNA signatures were apparent for each ND, the unique observation in our study was that hsa-miR-30b-5p overlapped between all four NDS, and has significant functional roles described across NDs. Furthermore, our results also show the evidence of functional convergence of miRNAs which was associated with the regulation of their cognate genes represented in pathways that included fatty acid synthesis and metabolism, ECM receptor interactions, prion diseases, and several signaling pathways critical to neuron differentiation and survival, underpinning their relevance in NDs. Envisioning this group of NDs together has allowed us to propose new ways of utilizing circulating miRNAs as biomarkers  and in visualizing diverse NDs more holistically . The critical molecular insights gained through the discovery of ND-associated miRNAs, overlapping miRNAs, and the functional convergence of microRNAs on vital pathways strongly implicated in neurodegenerative processes can prove immensely valuable in the identifying new generation of biomarkers, along with the development of miRNAs into therapeutics.