Genetic characterisation of neurodegenerative disorders

Our global population is ageing and an ever increasing number of elderly are affected with neurodegenerative diseases, including the subjects of the studies in this work, Alzheimer's disease (AD), Parkinson's disease (PD), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). On strong evidence that several genes may influence the development of sporadic neurodegenerative diseases, the genetic association approach was used in the work of this thesis to identify the multiple variants of small effect that may modulate susceptibility to common, complex neurodegenerative diseases. It has been shown that the common genetic variation of one of these susceptibility genes, MAPT, that of the microtubule associated protein, tau, is an important genetic risk factor for neurodegenerative diseases. There are two major MAPT haplotypes at 17q21.31 designated as H1 and H2. In order to dissect the relationship between MAPT variants and the pathogenesis of neurodegenerative diseases, the architecture and distribution the major haplotypes of MAPT have been assessed. The distribution of H2 haplotype is almost exclusively in the Caucasian population, with other populations having H2 allele frequencies of essentially zero. A series of association studies of common variation of MAPT in PSP, CBD, AD and PD in different populations were performed in this work with the hypothesis that common molecular pathways are involved in these disorders. Multiple common variants of the H1 haplotypes were identified and one common haplotype, H1c, showed preferential association with PSP and AD. A whole-genome association study of PD was also undertaken in this study in order to detect if common genetic variability exerts a large effect in risk for disease in idiopathic PD. Twenty six candidate loci have been found in this whole-genome association study and they provide the basis for our investigation of disease causing genetic variants in idiopathic PD.EThOS - Electronic Theses Online ServiceGBUnited Kingdo