BACKGROUND: Schizophrenia is a complex genetic disorder with no clear pattern of inheritance. Epigenetic modification of genes may thus play a role in its transmission. METHODS: In our study, 439 families with at least two ill siblings with schizophrenia (208 with unilineal transmission) were examined for evidence of a parent-of-origin effect (e.g., evidence of parental imprinting on the familial transmission of schizophrenia). RESULTS: No significant difference in the prevalence of maternal compared with paternal transmission was found.
Journal of Neurology, Neurosurgery, and Psychiatry
OBJECTIVES: Cerebellar haemangioblastoma occurs sporadically or as a component tumour of autosomal dominant von Hippel-Lindau disease. Biallelic inactivation of the VHL tumour suppressor gene, which is located on chromosome 3p, has been shown to be involved in the pathogenesis of both tumour entities. Mechanisms of VHL inactivation are intragenic mutations, mitotic recombination events, and hypermethylation of the promoter region.
How will the social sciences take advantage of the revolution that has taken place in biology during the past two decades? Over the last fifteen years, neuroimaging has allowed the study of human cognition and emotion within psychology to achieve close alliances with biology through the development of cognitive and affective neuroscience. There is little doubt that a similar alliance between psychology and biology will occur in the domain of human brain development.
Zeitschrift Fur Psychosomatische Medizin Und Psychotherapie
The paper discusses a variety of perspectives of psychoanalytic psychosomatics in the past, the present and the future. An epigenetic model of scientific development is introduced and developmental strains in psychosomatic medicine are evaluated according to the claims of the bio-psycho-social model. In historical terms, the psychological dimension of psychoanalytic psychosomatics has been the first strain to be elaborated; it is being extended still.
Genomic imprinting is an epigenetic phenomenon affecting a small number of genes that leads to expression from only one parental allele. Several imprinted genes are important for neurologic development and function and several neurobehavioral disorders are caused by genetic defects involving imprinted genes. For some genes, the imprinting is tissue specific, leading to biallelic expression in some tissues and monoallelic expression in other tissues.
Neurochemical and structural prefrontal cortex abnormalities, including decreased reelin and glutamic acid decarboxylase (GAD)(67) expression, decreased thickness, increased neuronal packing density and decreased neuropil and dendritic spine number, are characteristics of schizophrenia neuropathology. Reelin is an extracellular matrix protein secreted by GABAergic interneurons that, acting through pyramidal neuron integrin receptors, provides a signal for dendritic spine plasticity.
Behavior is shaped by a variety of genetic and epigenetic mechanisms, including those underlying anxiety and fear. Neuropeptides are ideal candidates to be involved in the regulation of emotional facets as they are released within the brain and act as neuromodulators/neurotransmitters; furthermore, their large number is prone to direct changes by mutations.
Cultural inheritance, a genetic-based inheritance system transmitted by the brain, has previously been proposed to underlie normal behaviour and mental disorders. In cultural inheritance epigenetic mechanisms are involved in gene expression. This paper proposes that since there are marked epigenetic mechanisms involved in the expression of genes underlying primary (idiopathic) mental disorders, epimutations, rather than genetic mutations, underlie these disorders.
Mammalian Genome: Official Journal of the International Mammalian Genome Society
Prader-Willi syndrome (PWS) results from loss of function of a 1.0- to 1.5-Mb domain of imprinted, paternally expressed genes in human Chromosome (Chr) 15q11-q13. The loss of imprinted gene expression in the homologous region in mouse Chr 7C leads to a similar neonatal PWS phenotype. Several protein-coding genes in the human PWS region are intronless, possibly arising by retrotransposition. Here we present evidence for continued acquisition of genes by the mouse PWS region during evolution.
OBJECTIVE: Some genome-wide scans and association studies for schizophrenia susceptibility genes have yielded significant positive findings, but there is disagreement between studies on their locations, and no mutation has yet been found in any gene. Since schizophrenia is a complex disorder, a study with sufficient power to detect a locus with a small or moderate gene effect is necessary.