Identifying Rare Genetic Variants Conferring Susceptibility To Multiple Sclerosis
Funder
National Health and Medical Research Council
Funding Amount
$293,898.00
Summary
Recently there has been success in identifying common genetic variants that confer susceptibility to multiple sclerosis. The variants that have been discovered so far have modest effects on risk of disease, and only explain a small proportion of familial aggregation of disease. In this study we aim to identify rarer genetic variants that have stronger effects on risk of disease, using new statistical methods and new methods to sequence very large amounts of DNA.
PArkin Co-Regulated Gene (PACRG), Parkin And Parkinsonism.
Funder
National Health and Medical Research Council
Funding Amount
$397,740.00
Summary
Parkinson's disease (PD) is a common neurodegenerative disorder affecting greater than two percent of individuals over the age of 65. The disease is characterised by tremor, slowness of movement, rigidity and postural instability. Current treatment regimes may provide some measure of symptomatic relief, but currently there is no treatment to halt or slow the progression of this debilitating disease. PD currently affects an estimated 35,000 people in Australia and this figure is predicted to incr ....Parkinson's disease (PD) is a common neurodegenerative disorder affecting greater than two percent of individuals over the age of 65. The disease is characterised by tremor, slowness of movement, rigidity and postural instability. Current treatment regimes may provide some measure of symptomatic relief, but currently there is no treatment to halt or slow the progression of this debilitating disease. PD currently affects an estimated 35,000 people in Australia and this figure is predicted to increase significantly as the population ages. PD is a complex disorder, the causes and disease mechanisms are not well understood. However, in the past 10 years several genes have been identified that can cause PD when disrupted. We have identified a new gene that we believe may be involved in PD. The overall aim of this proposal is to characterise this gene and what role it plays in the development of PD. Understanding the expression and function of this gene may significantly advance our understanding of this disorder. Using these results, we aim to model Parkinson's disease in cellular and animal systems; these may provide powerful insight into the molecular pathway(s) perturbed in PD and a means to develop novel therapeutic approaches to alleviate or prevent the disorder.Read moreRead less
Predictors Of Response To Antidepressants: Utility Of Behavioural, Neuroimaging And Genetics Data
Funder
National Health and Medical Research Council
Funding Amount
$310,071.00
Summary
Major depressive disorder (MDD) is projected to cause the second greatest global burden of disease by 2020, highlighting the urgent need for valid predictors of effective treatment response. Currently, there are no accurate predictors of response to antidepressants in MDD, and successful treatment relies greatly on 'trial and error'. This process is demanding on health resources, and may be a factor in the high suicide rates in depressed patients. Previous research on treatment response has been ....Major depressive disorder (MDD) is projected to cause the second greatest global burden of disease by 2020, highlighting the urgent need for valid predictors of effective treatment response. Currently, there are no accurate predictors of response to antidepressants in MDD, and successful treatment relies greatly on 'trial and error'. This process is demanding on health resources, and may be a factor in the high suicide rates in depressed patients. Previous research on treatment response has been limited by recruitment of small, heterogeneous patient samples, lack of placebo control, and a failure to examine task related activity in brain imaging studies. Perhaps one of the more troubling aspects of research that aims to predict treatment response to antidepressant medications is the use of commonly used outcome measures such as the Hamilton Rating Depression Scale (HAM-D), which were developed long before current classification systems of depression came into use. The US Federal Drug Administration has recently identified what they call a translational gap such that behavioural and biological measures are the most robust for detection of disorders such as depression, yet these measures remain to be translated into clinical tools that can be used to evaluate treatment. The aim of the current study therefore is to determine whether genetic variability is related to treatment outcome as defined by a more objective outcome measure (facial expression perception) using a randomised controlled design. The study will also determine whether brain measures (fMRI, EEG) enhance the prediction of SSRI response to both clinical and behavioural measures, over and above the genetic contribution.Read moreRead less
Identification Of Genes For X-linked Mental Retardation.
Funder
National Health and Medical Research Council
Funding Amount
$675,228.00
Summary
We propose to identify novel heritable causes of intellectual disability using 22 large and well-characterised families from Australia. In these families we have refined the location of the genetic defect to the chromosome X and excluded the contribution of all so far known genes. We will achieve this using the technology of massive parallel sequencing. At the completion of the project we will have identified novel causes of intellectual disability and devised tests to identify them.
Identification And Characterisation Of Phenotypic Modifier Genes In Familial Alzheimer's Disease
Funder
National Health and Medical Research Council
Funding Amount
$413,250.00
Summary
Alzheimer's disease (AD) is the most common cause of dementia the fourth most common cause of death. There are no effective cures for AD and those drugs currently available are of very limited value in delaying the onset and progression of this invariably fatal disease. AD is diagnosed by two key features in the brain, dense plaques composed of the amyloid beta peptide, and tangles composed of the tau protein. The identification of new therapeutic targets, such as the enzymes which produce amylo ....Alzheimer's disease (AD) is the most common cause of dementia the fourth most common cause of death. There are no effective cures for AD and those drugs currently available are of very limited value in delaying the onset and progression of this invariably fatal disease. AD is diagnosed by two key features in the brain, dense plaques composed of the amyloid beta peptide, and tangles composed of the tau protein. The identification of new therapeutic targets, such as the enzymes which produce amyloid beta peptide, and the development of drugs that interact with these targets offers the prospect of developing treatments to delay disease onset, retard or even halt the development of this relentlessly progressive disease. Our research focuses on the genes that are involved in variant forms of AD. One neuropathological variant form we and others have described is characterised by large diffuse (cotton wool) amyloid plaques. Cotton wool plaque pathology is associated with AD causing mutations in the presenilin 1 (PS-1) gene. Another clinical AD variant that we have described is characterised by the presence of spastic paraparesis (SP). SP is associated with PS-1 mutations, but when present delays disease onset. We have identified two potential modifier genes which are likely to be directly involved in the production of cotton wool plaques or modifying the effect of PS-1 mutations and the occurence of SP. For both genes, the goal of this project is to use a range of genetic approaches to clone the modifier genes by and to assess their effects on the clinical and pathological development of AD. By studying the effects of genes which act to modify the effects of the PS-1 mutations in these variant forms of AD we hope to gain a greater understanding of how the plaques and tangles actually lead to the clinical symptoms of the disease and to gain insights into new ways in which AD may be treated.Read moreRead less
Molecular Genetics Of Dyslexia: A Component Processes Approach
Funder
National Health and Medical Research Council
Funding Amount
$348,960.00
Summary
With the advent of the human genome project, Australian researchers into serious childhood reading disorders are now in a position to make breakthroughs in understanding the complex linkages between genes and dyslexia. It is widely acknowledged that previous studies on the genetics of dyslexia have been limited by their failure to distinguish the different component processes in reading and the different patterns of dyslexia that they produce, and by being unable to look widely across the human ....With the advent of the human genome project, Australian researchers into serious childhood reading disorders are now in a position to make breakthroughs in understanding the complex linkages between genes and dyslexia. It is widely acknowledged that previous studies on the genetics of dyslexia have been limited by their failure to distinguish the different component processes in reading and the different patterns of dyslexia that they produce, and by being unable to look widely across the human genome. This new research addresses these two problems. Firstly, the researchers have developed a computational model of reading that identifies around a dozen basic mental processes which are recruited during skilled reading. This model provides the extremely precise phenotypes required for genetic research. Secondly, the researchers will take advantage of both very high density scans within known regions of interest on chromosomes 2,6, and 15, as well as a genome-wide scan of 400 markers small elements of DNA whose position within the genome is known, thus allowing researchers to narrow-down the location of new genes for reading. The research thus promises not only to refine our understanding of the basis for three previous genetic markers of dyslexia, but also to potentially uncover new genes related to specific elements of reading across the genome. The project pools the resources of the Macquarie Centre for Cognitive Science, the Australian Genome Research Facility, and The Garvan Institute and the researchers hope that the work will lead eventually to identifying the genes for dyslexia and to improved diagnosis and treatment of reading disorders in Australia.Read moreRead less
Neurons in the two hemispheres of the brain make connections with each other via a large fibre tract called the corpus callosum. In over fifty different human congenital syndromes the corpus callosum fails to form properly. Such syndromes, which include Aicardi syndrome, Andermann syndrome, Shapiro syndrome and Acrocallosal syndrome, can result in mental retardation, seizures, lack of motor coordination and ocular abnormalities in children. Our data on both mouse and human brain development show ....Neurons in the two hemispheres of the brain make connections with each other via a large fibre tract called the corpus callosum. In over fifty different human congenital syndromes the corpus callosum fails to form properly. Such syndromes, which include Aicardi syndrome, Andermann syndrome, Shapiro syndrome and Acrocallosal syndrome, can result in mental retardation, seizures, lack of motor coordination and ocular abnormalities in children. Our data on both mouse and human brain development show that the mouse is an excellent model system for understanding how the brain becomes wired up during development and what may go wrong in these disorders. Here we investigate the role of a family of genes called nuclear factor one (Nfi) genes in brain development. When mutated in mice, members of this gene family, principally Nfia and Nfib, cause severe malformations of the brain. The phenotype inlcudes a failure to form some midline glial populations, the expansion of the cingulate cortex and loss of the corpus callosum. The propoer formation of midline glial populations and the cingulate cortex are essential to callosal fomration and correct brain wiring. Defects in brain wiring in the cingulate cortex during development may underlie disorders such as schizophrenia, bipolar disorder and depression. In this project we will address the mechanism of function underlying the control of brain development by the Nfi genes. The expected outcomes of this research are to identify new mechanisms and genetic pathways critical to the formation of connections between the two sides of the brain and proper formation of the cingulate cortex. These results will improve our understanding of how the brain forms and what mechanisms may be disrupted during development that result in neurological and cognitive deficits in children and adults.Read moreRead less
Dominant Repeat Expansion Diseases - A Common RNA Mediated Pathogenic Pathway?
Funder
National Health and Medical Research Council
Funding Amount
$281,118.00
Summary
There are fourteen human genetic diseases that are caused by a similar mutation mechanism and have similar clinical outcomes - the loss of function, degeneration and eventual death of nerve cells. This group of diseases includes Huntington's Disease. They are transmitted from parent to offspring such that each child of an affected parent has 50% risk of inheriting the affected gene and therefore developing the disease. The symptoms of these diseases typically develop later in life - between the ....There are fourteen human genetic diseases that are caused by a similar mutation mechanism and have similar clinical outcomes - the loss of function, degeneration and eventual death of nerve cells. This group of diseases includes Huntington's Disease. They are transmitted from parent to offspring such that each child of an affected parent has 50% risk of inheriting the affected gene and therefore developing the disease. The symptoms of these diseases typically develop later in life - between the ages of 35 and 50 years. While the different genes for these diseases have been identified the pathways that lead from their similar form of mutation to their similar clinical outcomes are not yet understood. Some evidence suggests that certain of these diseases have a common toxic component but this component is not shared by all of the disease genes and so an additional agent that they have in common is being sought. This research will use a genetic model organism - the vinegar fly, Drosophila melanogaster, to test the identity of a good candidate (RNA) for a common toxic agent and to provide information about the pathway by which RNA leads to nerve cell degeneration and death. Accurate and complete knowledge of the identity and composition of the pathways that lead from the mutation to the disease are crucial for correct target identification in the development of drug leads.Read moreRead less
Truncating Presenilin Mutations And Their Effects On Gamma-secretase Activity, Tau And Beta-catenin
Funder
National Health and Medical Research Council
Funding Amount
$414,005.00
Summary
Alzheimer's disease (AD) and cancer are increasingly important both in terms of human suffering and the burden of care it imposes on society and the economy. Sporadic (non-inherited) AD is the most common form of dementia but is poorly understood. The PRESENILIN genes, PSEN1 and PSEN2, are the major sites for mutations causing inherited AD and are also implicated in cancer. Using the zebrafish embryo model we have discovered that, contrary to current thought, mutations that truncate presenilin p ....Alzheimer's disease (AD) and cancer are increasingly important both in terms of human suffering and the burden of care it imposes on society and the economy. Sporadic (non-inherited) AD is the most common form of dementia but is poorly understood. The PRESENILIN genes, PSEN1 and PSEN2, are the major sites for mutations causing inherited AD and are also implicated in cancer. Using the zebrafish embryo model we have discovered that, contrary to current thought, mutations that truncate presenilin proteins potently suppress normal presenilin activity. (They are so called, dominant negatives). This means that they are lethal for embryo development and explains why such mutations have never been found in inherited AD. Notably, this discovery could only be made using a subtle form of gene manipulation that is possible in zebrafish embryos. Our work has also established the first assay for the non-apoptotic (non-cell death) function of PSEN2 and has shown that PSEN2 activity is inhibited by truncated PSEN1. This is the first indication of possible interaction between PSEN1 and PSEN2 proteins at normal physiological expression levels. Loss of presenilin activity promotes cancer. Truncated presenilin proteins could be produced by errors in gene transcription (aberrant transcript splicing) common in cancerous cells. This suggests that truncated, dominant negative forms of presenilin produced through aberrant splicing (or mutation in precancerous cells) might be common in tumour formation. The proposed research will define the region of PSEN1 in which truncation leads to dominant negative activity. This will allow further examination of the role of presenilins in the cell signalling pathways involved in AD and cancer. We will also investigate the role that age-related truncation of presenilins in human cells can play in the formation of sporadic AD. This may reveal a common molecular link between the inherited and sporadic forms of this disease.Read moreRead less
Mutation Analysis Of Novel Candidate Genes For X-linked Charcot Marie Tooth (CMTX3) Neuropathy.
Funder
National Health and Medical Research Council
Funding Amount
$191,434.00
Summary
Our goal is to explore how peripheral nerves degenerate by identifying the gene mutation causing an X linked form of Charcot Marie Tooth neuropathy (CMTX3). Using bioinformatic resources and state of the art gene mutation scanning we will complete characterisation and systematic screening of candidate genes and novel transcripts in the region. Discovery of this gene will provide a means to determine mechanisms causing axonal degeneration and lead to targeted therapeutic treatment strategies.