Functional Significance Of MeCP2 Target Genes In The Pathogenesis Of Rett Syndrome.
Funder
National Health and Medical Research Council
Funding Amount
$476,815.00
Summary
Rett syndrome (RTT) is a devastating progressive disorder affecting motor and intellectual development. It is characterised by normal development for the first 6-12 months of life, followed by developmental regression with the loss of learned purposeful hand function, loss of acquired speech and communicative abilities, sometimes leading to the incorrect diagnosis of autism. It is a genetic disorder and contributes to a substantial proportion of girls with severe mental retardation. In 1999, a g ....Rett syndrome (RTT) is a devastating progressive disorder affecting motor and intellectual development. It is characterised by normal development for the first 6-12 months of life, followed by developmental regression with the loss of learned purposeful hand function, loss of acquired speech and communicative abilities, sometimes leading to the incorrect diagnosis of autism. It is a genetic disorder and contributes to a substantial proportion of girls with severe mental retardation. In 1999, a gene (called MECP2) was identified which appears to be the cause of RTT in at least 80% of affected girls and women. Now that the gene responsible for many cases of RTT has been found, new questions are being asked. Why are the effects of these mutations restricted to the brain? Which other genes might play a role in the symptoms seen in RTT? The focus of this research project is to examine these 2 questions. Using new research techniques, we have identified genes that are themselves secondarily affected by mutations in the MECP2 gene. We wish to study these genes in more detail, with the aim being to gain a greater understanding of how these genes contribute to the onset of impaired brain function in girls and women with RTT. These insights are essential foundations for the development and evaluation of new and more specific therapies for this as yet incurable disorder.Read moreRead less
STK9, A Second Rett Syndrome Gene: Genetic And Functional Studies
Funder
National Health and Medical Research Council
Funding Amount
$468,750.00
Summary
Rett syndrome (RTT) is a devastating progressive disorder affecting motor and intellectual development. It is characterised by normal development for the first 6-12 months of life, followed by developmental regression with the loss of learned purposeful hand function, loss of acquired speech and communicative abilities, sometimes leading to the incorrect diagnosis of autism. It may be the most common cause of progressive mental retardation in girls, with an estimated prevalence in Australia of 1 ....Rett syndrome (RTT) is a devastating progressive disorder affecting motor and intellectual development. It is characterised by normal development for the first 6-12 months of life, followed by developmental regression with the loss of learned purposeful hand function, loss of acquired speech and communicative abilities, sometimes leading to the incorrect diagnosis of autism. It may be the most common cause of progressive mental retardation in girls, with an estimated prevalence in Australia of 1 per 10,000 females under the age of twelve years. It is a genetic disorder and occurs almost exclusively in females. In 1999, a gene (called MECP2) was identified which appears to be the cause of RTT in most girls and women with RTT. However, for 5 - 10% of RTT subjects, no gene change is found in the MECP2 gene, raising the possibility that other genes may also be responsible for RTT. Our research group has identified one of these genes. Known as STK9, little is known about this gene's function. Of great interest is the fact that our studies suggest that STK9 could also be a caus of intellectual disability in other patients, and with autism. The focus of this research project is to explore how common gene changes in STK9 are in a large number of children with RTT, intellectual disability and seizures, and autism with intellectual disability and seizures. Using cutting edge research technology, we will go on to study how STK9 interacts with MECP2 and other genes, in order to better understand how these genes may be detrimentally affecting brain function in girls and women with Rett syndrome and other neurological disorders. These studies will give us a greater understanding of normal brain development and function.Read moreRead less
Prevalence And Characterisation Of FMR1 Gene's Premutation Carriers Amongst Older Males Presenting With Tremor/ataxia
Funder
National Health and Medical Research Council
Funding Amount
$199,450.00
Summary
The study concerns a novel form of progressive neurological disorder associated with tremor and body imbalance occurring in older males and caused by a small expansion of the trinucleotide (CGG) repeat in a fragile X (FMR1) gene. This expansion is termed 'premutation', in contrast with the full mutation, where a large expansion of the CGG repeat in this gene causes Fragile X Syndrome, a common form of intellectual disability. While brain anomaly in the full mutation is caused by a deficit of the ....The study concerns a novel form of progressive neurological disorder associated with tremor and body imbalance occurring in older males and caused by a small expansion of the trinucleotide (CGG) repeat in a fragile X (FMR1) gene. This expansion is termed 'premutation', in contrast with the full mutation, where a large expansion of the CGG repeat in this gene causes Fragile X Syndrome, a common form of intellectual disability. While brain anomaly in the full mutation is caused by a deficit of the FMR1 specific protein product (FMRP), the pathways from premutation to a neurological disorder are unknown. In this disorder, neurological dysfunction is associated with brain atrophy visible in magnetic resonance (MRI) images. Molecular studies showed increased levels of 'messenger' RNA (mRNA), which indicates overexpression of FMR1 gene . Our own study showed significantly increased (41.7%) prevalence of neurological involvement in male premutation carriers aged >50, compared with age-matched norms. Moreover, a screening of patients with two neurological disorders associated with tremor showed a significant increase of premutation carriers (5%- 22%). The aim of this study is to test hypotheses about the association of late-onset neurological disorders of unknown cause presenting tremor and imbalance, with a fragile X premutation in males, by screening for the presence of this premutation; and then conducting a full assessment of the identified premutation carriers, including detailed neurological, neuropsychological and MRI tests, to establish the spectrum of neurological involvement. This involvement will be correlated with the molecular (DNA, mRNA, FMRP) findings. The results will contribute to understanding the mechanisms of neurological involvement caused by this premutation. Moreover, estimation of the prevalence of this premutation in relevant neurological disorders will impact on standard diagnostic, and possibly future treatment approaches in neurology clinics.Read moreRead less
Clinical Efficacy Of Haematopoietic Stem Cell Transplantation In Mucopolysaccharidosis IIIA
Funder
National Health and Medical Research Council
Funding Amount
$508,051.00
Summary
Lysosomal storage disorders (LSD) are inherited diseases that affect about 1 in 7700 Australian children; all share common physical symptoms include heart and breathing difficulties, stiff joints, skeletal deformities, enlarged head, and a characteristic facial appearance. Two-thirds of patients will also develop brain disease. The lysosome is a component of each cell in the human body; its role it is to break down and remove waste from the cell. This involves a series of proteins (enzymes) that ....Lysosomal storage disorders (LSD) are inherited diseases that affect about 1 in 7700 Australian children; all share common physical symptoms include heart and breathing difficulties, stiff joints, skeletal deformities, enlarged head, and a characteristic facial appearance. Two-thirds of patients will also develop brain disease. The lysosome is a component of each cell in the human body; its role it is to break down and remove waste from the cell. This involves a series of proteins (enzymes) that act in sequence. A LSD arises when the lysosome lacks the activity of one protein in this chain. This loss of protein activity means that the waste removal process is impaired. Waste begins to 'store', clogging the cell and interfering with its usual functions. This gives rise to devastating symptoms that worsen over time as storage increases. Brain disease in LSD has profound effects on the child: mental capacity declines, they become hyperactive and aggressive and progressively lose learned skills (e.g. walking, talking) and control of bodily functions. Mucopolysaccharidosis (or MPS) type IIIA is a LSD that affects the brain. Bone marrow transplantation (BMT) is an accepted treatment for many diseases, including cancer. However, unlike cancer and some LSD, BMT does not work in MPS IIIA children. The reasons for this are unknown. This project is important in understanding the basic mechanisms that prevent this form of therapy from working in these children. If we can understand what prevents its effectiveness, we can devise methods to overcome it and potentially offer MPS IIIA (and other LSD that do not respond to BMT) a viable treatment option. We have a colony of mice affected by MPS IIIA; their symptoms are similar to that seen in humans, making them ideal for this study.Read moreRead less
Cisterna Magna Delivery Of Therapeutic Lysosomal Enzyme To Correct CNS Pathology In Lysosomal Storage Disorders
Funder
National Health and Medical Research Council
Funding Amount
$760,282.00
Summary
Lysosomal storage disorders (LSD) are inherited diseases that affect about 1 in 7700 Australian children; all share common physical symptoms include heart and breathing difficulties, stiff joints, skeletal deformities, enlarged head, and a characteristic facial appearance. Two-thirds of patients will also develop brain disease. The lysosome is a component of each cell in the human body; its role it is to break down and remove waste from the cell. This involves a series of proteins (enzymes) that ....Lysosomal storage disorders (LSD) are inherited diseases that affect about 1 in 7700 Australian children; all share common physical symptoms include heart and breathing difficulties, stiff joints, skeletal deformities, enlarged head, and a characteristic facial appearance. Two-thirds of patients will also develop brain disease. The lysosome is a component of each cell in the human body; its role it is to break down and remove waste from the cell. This involves a series of proteins (enzymes) that act in sequence. A LSD arises when the lysosome lacks the activity of one protein in this chain. The loss of protein activity impairs the waste removal process. Waste begins to 'store', clogging the cell and interfering with its usual functions. This gives rise to devastating symptoms that worsen over time as storage increases. Brain disease in LSD has profound effects on the child: mental capacity declines, they become hyperactive and aggressive and progressively lose learned skills (e.g. walking, talking) and ability to control bodily functions. Artifically made protein is being successfully used to treat some LSD via intravenous injection. However, it is not able to access the brain because of a protective barrier that surrounds it. This project tests a method to deliver protein to the brain to reduce and stop waste build-up. It involves the injection of artificially made protein into the fluid surrounding the brain and spinal cord using techniques being used to treat other diseases. This method is likely to be the quickest way in which we can treat both the body AND the brain of an affected child. We have diagnosed animal models who were born with a LSD with brain disease, called MPS IIIA. Their symptoms are similar to that seen in humans over the course of the disease, making them ideal for study in this project. Success in this project will allow us to advance this treatment to human trials.Read moreRead less