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
Linkage And Association Studies Of Schizophrenia In An Isolated Population.
Funder
National Health and Medical Research Council
Funding Amount
$693,726.00
Summary
The cause of schizophrenia is unknown, but there is good evidence that genes play a role. Geneticists do not fully understand how the disease is inherited, but it is very complex, and several interacting genes as well as environmental factors are likely involved. To address this complexity, we have recruited large schizophrenia pedigrees from the Iban of Sarawak, a geographically and genetically isolated population. This sample will help clarify the genetics of this devastating illness.
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
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