A Genetic Study Of Schizophrenia In The Brahmin Of Tamil Nadu
Funder
National Health and Medical Research Council
Funding Amount
$267,226.00
Summary
The cause of schizophrenia is unknown, but there is good evidence that genes play a role. Geneticists do not fully understand how it is inherited, but it is very complex, and several interacting genes as well as environmental factors are probably involved. Societies such as Australia are genetically diverse because people from many different ethnic groups have intermarried. To detect susceptibility genes in this type of population, we must study very large patient samples. Alternatively, we can ....The cause of schizophrenia is unknown, but there is good evidence that genes play a role. Geneticists do not fully understand how it is inherited, but it is very complex, and several interacting genes as well as environmental factors are probably involved. Societies such as Australia are genetically diverse because people from many different ethnic groups have intermarried. To detect susceptibility genes in this type of population, we must study very large patient samples. Alternatively, we can study genetically homogenous patient samples, found in isolated gene-pool populations. One such population is the Brahmin people in Tamil Nadu, a south-eastern state of India. The Brahmin are descended from the Aryan peoples who migrated into southern India 2000 years ago. In the Hindu caste system, Brahmin are the highly educated priest class, and enjoy a privileged position in society. Traditionally, marriages among the Brahmin of Tamil Nadu have been prearranged, with a preference for first-cousin marriages. As well as this cultural and historical evidence, genetic marker studies confirm that this population is a suitable genetic isolate. In this project, genetic material (DNA) will be collected from Brahmin schizophrenic patients and their families. Diagnostic data, detailed family data, and blood samples will be gathered from 90-100 extended families, each containing two or more ill individuals. Analysis of their genetic code will enable a search for possible schizophrenia susceptibility genes and a systematic search for a mutation. If found, this will greatly improve our understanding of schizophrenia, and stimulate the search for similar genes in other samples world-wide, including Australia where schizophrenia costs $3 billion annually in terms of treatment and lost jobs. If schizophrenia genes can be found, it may be possible to find better treatments that correct the basic causes of the illness and identify factors that protect against the illness.Read moreRead less
Identification Of Schizophrenia Susceptibility Genes: A Collaborative Project With The University Of Indonesia
Funder
National Health and Medical Research Council
Funding Amount
$546,825.00
Summary
Schizophrenia is present in all populations at a similar incidence. The project aims to identify genetic risk factors in three genomic regions previously detected by us in a genome-scan for genetic linkage in 152 Indonesian families. Colleagues at the University of Indonesia will collect an additional sample of 2000 individuals for replication. This sample will be available for research in Australia. Knowledge of risk factors will aid in diagnosis, prevention, and development of novel therapies.
ADHD And Comorbidity: Implications For Clinical Practice And Molecular Genetics
Funder
National Health and Medical Research Council
Funding Amount
$284,878.00
Summary
ADHD is emerging as the most common, controversial childhood behavioural problem. Previously we have shown that much of the confusion may lie in the fact that ADHD is inherited as a continuum throughout the entire population, only some people having such a strong genetic potential that they warrant the label ADHD. The threshold to achieve this label is partly a community one, leading to the argument over who should be labelled and treated. This grant goes further in examining the possibility tha ....ADHD is emerging as the most common, controversial childhood behavioural problem. Previously we have shown that much of the confusion may lie in the fact that ADHD is inherited as a continuum throughout the entire population, only some people having such a strong genetic potential that they warrant the label ADHD. The threshold to achieve this label is partly a community one, leading to the argument over who should be labelled and treated. This grant goes further in examining the possibility that there is more than one type of ADHD. Some ADHD children have other behavioural problems such as conduct disorder or learning problems. Some have problems throughout their lives while others grow out of it. In Australia we are unique in having developed the most extensive twin databases world-wide and have already studied aspects of ADHD both in the children and their parents. In this grant we shall explore whether there are distinct genetic types of ADHD, characterised not just by their ADHD symptoms but also by the other behavioural problems they experience and by what happens as they grow-up. Such information is invaluable in developing a treatment program dealing with all aspects of the ADHD and also addresses the question of what will happen as they get older. No other study internationally has such extensive data to address these key questions., vital both to clinicians and families. Given the significant genetic component to ADHD, the next possibility is to find the genes involved in the different types. Knowing what these genes do may help in the development of medications more targeted to specific patterns of problems. Recently genes have been identified which may be involved in specific types of ADHD, as well as genes involved in associated problems such as reading disability and substance abuse. This study offers the potential to clearly identify the role of these genes and so assist in improved diagnosis and treatment interventions.Read moreRead less
Memory, Synaptic Plasticity And Gene Networks In Schizophrenia
Funder
National Health and Medical Research Council
Funding Amount
$1,142,138.00
Summary
Schizophrenia affects about 1% of the population. Its typical progression over a lifetime leads to long-term impairment of cognition, reality distortion, and an impoverished quality of life. Most likely, multiple genes, interacting together or with environmental factors, are involved. Using a novel approach to its partition, WA researchers aim to unravel complex networks of genes affecting memory and brain function in a cognitive deficit subtype of schizophrenia they have identified recently.
Twin and family studies show schizophrenia has a genetic basis. Attempts to find and characterise the underlying genes have not been successful so far. A main reason for this is that insufficient attention has been paid to the complexity of the underlying genetic architecture of the disorder. The pathway from genes to symptoms of schizophrenia is likely to involve elementary processes at neuronal and neural circuitry levels that vary between individuals and this variation is reflected in a grade ....Twin and family studies show schizophrenia has a genetic basis. Attempts to find and characterise the underlying genes have not been successful so far. A main reason for this is that insufficient attention has been paid to the complexity of the underlying genetic architecture of the disorder. The pathway from genes to symptoms of schizophrenia is likely to involve elementary processes at neuronal and neural circuitry levels that vary between individuals and this variation is reflected in a graded susceptibility to schizophrenia. During the last three years we have recruited a large number of families with at least one family member diagnosed with schizophrenia. The proband and all participating first-degree relatives have been assessed with a neurocognitive test battery including measures of sustained attention, working memory, speed of information processing, auditory verbal learning and executive function. Analysis of the neurocognitive data on this sample produced strong evidence that several measures are altered in patients with schizophrenia and a proportion of their asymptomatic first-degree relatives compared to unrelated normal controls. In the study we will systematically search the human genome for DNA markers linked to these measures. This will set the stage for the systematic search and characterisation of the underlying genes. This will allow us to better understand the predisposition to develop schizophrenia. In the individual case it is likely that this vulnerability results from a high-risk combination of a number of relatively common alleles which contribute to basic neural processes.Read moreRead less
An Investigation Of The Aetiology Of Eating Disorders: Interactions Between Genes And Environmental Risk Factors.
Funder
National Health and Medical Research Council
Funding Amount
$225,000.00
Summary
Eating disorders, along with substance abuse, carry the highest risk of premature death, from both natural and unnatural causes, out of 27 mental disorder categories. Eating disorders, including anorexia nervosa, bulimia nervosa, and binge-eating disorder, affect about 6% of Australian women. Despite increased levels of research into the aetiology of eating disorders over the last 20 years, little knowledge exists as to which risk factors cause women to attempt weight loss to the point of increa ....Eating disorders, along with substance abuse, carry the highest risk of premature death, from both natural and unnatural causes, out of 27 mental disorder categories. Eating disorders, including anorexia nervosa, bulimia nervosa, and binge-eating disorder, affect about 6% of Australian women. Despite increased levels of research into the aetiology of eating disorders over the last 20 years, little knowledge exists as to which risk factors cause women to attempt weight loss to the point of increasing their risk of premature mortality. A review of twin studies in eating disorders concludes that there is increasing evidence to suggest that genetic factors play a role in the development of eating disorders. In addition, a recent series of studies, examining risk factors before the age of eating disorder onset, have found the following events to specifically predict the development of an eating disorder as opposed to another psychiatric condition: negative self-evaluation, parental alcoholism, low parental contact and high parental expectations, critical comments about weight, shape or eating during childhood, and childhood obesity. To date, no studies have attempted to integrate the findings from twin studies with the findings from early risk factor studies. Specifically, the ways in which genes interact with the environment to increase the chances of genetic vulnerability to an eating disorder being expressed have not been examined. The proposed project seeks to investigate precisely these interactions between genes and the environment, by examining a large number of female twins, aged 29-37. An enhanced understanding of how genes interact with the environment to either increase the chances that a woman will develop an eating disorder, or alternatively to protect a woman from developing an eating disorder, will benefit our understanding of how to target prevention and treatment strategies.Read moreRead less
Children Of Parents With Mental Illness: A Population-based Study
Funder
National Health and Medical Research Council
Funding Amount
$774,715.00
Summary
Schizophrenia, bipolar disorder and major depression account for about 16% of the global burden of disease, according to estimates by the World Health Organization and the World Bank. These disorders tend to run a chronic or recurrent course, with devastating impact on sufferers and their families. We know today that part of their causes are genetic and may be transmitted to the next generation. However, another part of the causation is likely to be environmental, involving maternal pregnancy co ....Schizophrenia, bipolar disorder and major depression account for about 16% of the global burden of disease, according to estimates by the World Health Organization and the World Bank. These disorders tend to run a chronic or recurrent course, with devastating impact on sufferers and their families. We know today that part of their causes are genetic and may be transmitted to the next generation. However, another part of the causation is likely to be environmental, involving maternal pregnancy complications, as well as psychosocial adversity and stressful events impacting children who happen to carry a genetic susceptibility to such disorders. To disentangle and understand better such effects, our research is focusing on families where genetic risk to the offspring is present, due to a mother suffering from one of these disorders. By linking data available on population databases in WA, we aim to follow up the childhood development and young adult health outcomes of all children born to women with schizophrenia, bipolar disorder or depression. Few studies of this kind have been done worldwide, and we expect that the WA study will answer many unresolved questions, leading to preventative and treatment interventions that would reduce adverse outcomes and improve the quality of life of families at risk.Read moreRead less
ADHD Grown-up: Genetic And Environmental Determinants Of The Adult Outcomes Of Childhood ADHD And Comorbid Conditions
Funder
National Health and Medical Research Council
Funding Amount
$289,542.00
Summary
ADHD remains a controversial issue especially in adulthood. There are many related behavioural problems including substance abuse, anxiety, depression, and personality disorders. Australia is such a focus for twin research that many twin families have taken part in several studies of different aspects of mental health over the years. This grant allows us to link the various datasets to create a unique longitudinal genetic resource and to examine the longterm outcomes.