It is a commonly held view that mild forms of MR are multifactorial,

while Glioma severe forms are largely due to catastrophic genetic defects, including chromosomal aberrations and mutations of single genes. Lehrke6,7 assumed that MR genes and genes determining the IQ were identical, and others speculated that risk factors for mild MR might be allelic variants of these genes,43,44 exerting a moderate effect on the IQ. As the number of MR genes is increasing, and in view of the novel methods for highthroughput mutation detection, everything seems to be in place for putting these ideas to the test. Acknowledgments The author would like to thank Sarah Shoichet, Vera Kalscheuer, Andreas Tzschach, Inhibitors,research,lifescience,medical and Reinhard Ullmann for critically reading the manuscript, and Gabriele Eder for secretarial assistance.
Schizophrenia

and bipolar affective disorder (bipolar disorder, manic depression) are major psychiatric disorders. They profoundly affect thought, perception, emotion, and behavior, and their symptoms Inhibitors,research,lifescience,medical cause significant social and/or occupational dysfunction. The World Health Organization ranks both disorders among the top 10 leading causes of the global burden of disease for the 15-to-44 age group. Schizophrenia Inhibitors,research,lifescience,medical and bipolar disorder are illnesses with a largely unknown pathophysiology and etiology. However, genetic epidemiology has demonstrated that modern psychiatric diagnostic criteria define disorders Inhibitors,research,lifescience,medical that are highly heritable. Estimates of heritability range between 70% and 90% for schizophrenia1 and 60% and 80% for bipolar disorder.2 It is generally accepted that the inheritance of psychiatric disorders

is complex. Multiple genetic and environmental factors contribute to the development of a disorder3-9 and it is possible Inhibitors,research,lifescience,medical that gene-gene interactions also occur.10,11 Extensive efforts have been made over the past 20 years to identify the susceptibility genes for psychiatric disorders on a molecular genetic level, although this has proven to be a far more difficult undertaking than was first anticipated. Until recently, the linkage approach and microscopic cytogenetic studies were the only available methods of systematically searching the genome. A disadvantage of these two methods is their low level of resolution. Anacetrapib Linkage studies have identified a series of chromosomal regions that are likely to contain susceptibility genes, and highly promising association findings have been obtained for selleck bio several genes in these regions (eg, neuregulin 1 [NRG1], G72/G30 locus, dystrobrevin-binding protein 1 [DTNBP1]).12-14 However, it has not yet been possible to identify any genetic variant that confers a direct functional effect and which is consistently associated with disease across populations. Cytogenetic studies have also generated some highly promising candidate genes such as the disrupted-in-schizophrenia-1 gene (DISCI).