Genetic epidemiology of atopy and asthma

Wan, Yize Isalina (2011) Genetic epidemiology of atopy and asthma. PhD thesis, University of Nottingham.

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Abstract

The evidence for genetic contributions to the development of asthma and atopy has been well established. Refining the major genetic factors underlying these contributions will lead to a greater understanding of the pathophysiology of these conditions and potentially identify novel therapeutic targets.

This thesis describes a series of studies designed primarily using genome-wide association (GWA) approaches to examine common single nucleotide polymorphisms (SNPs) contributing to these phenotypes in the Caucasian population. Susceptibility to atopy was assessed using both non-parametric association tests of SNPs across the genome and focused analysis of two regions on chromosomes 3p22.1-q22.1 and 17p12-q24.3 previously identified through a meta-analysis of genome-wide linkage studies (GSMA). The discovery cohort consisted of 1,083 cases and 2,770 controls, replication analyses were undertaken in four independent population cohorts. A GWA study of severe asthma was carried out in 933 cases and 3,346 controls with replication in a further 231 cases and 1,345 controls. The contribution of SNPs within all previously reported asthma susceptibility loci identified using a comprehensive literature search was also evaluated.

Overall, there is evidence for a large number of loci influencing both atopy and severe asthma, each harbouring modest effects. A number of potentially novel loci meeting nominal significance in both GWA studies have been identified requiring further work. Strong evidence was found to support the IL1RL1-IL33 signalling pathway in asthma pathogenesis. Molecular characterisation of the 5’ untranslated regions of IL1RL1 and IL33 suggest a complex regulatory role of identified common variants involving multiple promoters for IL1RL1. A number of asthma specific variants within the chromosome 2q12 and 9p24.1 regions were detected using next generation re-sequencing in homogenised pools of cases and controls warranting further analyses.

This work has identified a potentially important pathway in which to focus the development of effective asthma therapies. Future directions will include functional analysis of replicated variants and tests of interactions between the multiple genetic and environmental factors likely to be involved in disease.

Item Type:Thesis (PhD)
Supervisors:Hall, I.P.
Sayers, I.
Faculties/Schools:UK Campuses > Faculty of Medicine and Health Sciences > School of Clinical Sciences
ID Code:2224
Deposited By:Miss Yize Isalina Wan
Deposited On:24 Feb 2012 14:10
Last Modified:24 Feb 2012 14:10

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