Developmental Disabilities Research Reviews最新文献

Developmental disorders such as subaverage intelligence, pervasive developmental disorders, and genetic syndromes are frequently associated with comorbid attention-deficit/hyperactivity disorder (ADHD) or ADHD-like symptoms. While there are not pharmacological cures for these developmental disorders, coinciding ADHD and ADHD-like symptoms that contribute to difficulties in psychosocial functioning are frequently able to be addressed by pharmacotherapy. This article reviews what is known about the efficacy and tolerability of pharmacological interventions for the treatment of children and adolescents suffering from developmental disorders and comorbid ADHD/ADHD-like symptoms. © 2010 Wiley-Liss, Inc. Dev Disabil Res Rev 2010;16:273–282.

Understanding the pharmacokinetics and pharmacodynamics of drugs used in psychopharmacology across the pediatric age spectrum from infants to adolescents represents a major challenge for clinicians. In pediatrics, treatment protocols use either standard dose reductions for these drugs for children below a certain age or use less conventional parameters such as weight for allometric dosing. The rationale behind this, however, is often lacking. In this review current available data on the developmental changes in absorption, distribution, metabolism, and elimination of drugs are presented with a specific focus on metabolic pathways, indicating significant differences in the development of enzymes involved in the biotransformation of drugs used in psychopharmacology. Major emphasis will be given to the genetic variation in CYP2D6 activity, the most important enzyme for the metabolism of many psychotropic medications. Finally, this review will summarize the role of the developmental pharmacologist in ensuring rational use of drugs in children with developmental disabilities and in translating pharmacological concepts from the bench to the clinic. © 2010 Wiley-Liss, Inc. Dev Disabil Res Rev 2010;16:233–238.

The review presented here describes the state of the art of pharmacological treatment of aggression in subjects with mental retardation (MR) summing up results for both, children and adults. In general, psychopharmacological treatment of disruptive behavior in individuals with MR is similar to the treatment in subjects without MR. Compared to individuals without MR medication should “start lower and go slower.” For children and adults results were similar but were obtained by somewhat different medications. There is evidence for the conventional antipsychotic zuclopenthixol having positive effects on disruptive behavior. Most studies described the atypical antipsychotic risperidone to control severe self-injurious behavior and other behavior problems in a variety of diagnoses. Anticonvulsants, antidepressants, and anxiolytic medications are reported as effective as well for the treatment of individuals with disruptive behavior. Aggression-related behavior often gets treated with stimulants or with stimulants combined with atypical neuroleptics. © 2010 Wiley-Liss, Inc. Dev Disabil Res Rev 2010;16:265–272.

The primary focus of pain research in intellectually disabled individuals is still on pain assessment. Several observational pain assessment scales are available, each with its own characteristics, its own target group and its own validated use. Observational studies report differences in the treatment of intra- and postoperative pain of intellectually disabled children and almost all children with intellectual disability have comorbidities that need to be addressed. The scope of research has started to broaden. In this review we aim to answer the question: Can we integrate validated ways of pain assessment and postoperative pain treatment in intellectually disabled children to develop specific analgesic algorithms? Regrettably there is little knowledge on possible interaction effects and other relevant pharmacological issues. Possible genotype–phenotype associations related to pain in children with Down syndrome have several promises as six possible candidate genes are located on chromosome 21. In conclusion, the pain assessment tools for intellectually disabled children are there. We should now focus on tailoring the pain treatment. To this aim we need to perform pharmacokinetic and pharmacodynamic studies of analgesics and obtain information about the genotype–phenotype relationships for pain. This can lead to the development of specific analgesic algorithms. © 2010 Wiley-Liss, Inc. Dev Disabil Res Rev 2010;16:248–257.

Children with developmental disabilities are at increased risk for epilepsy with a prevalence rate higher than the general population. Some of the more common developmental disorders in childhood and the features of epilepsy in these conditions are discussed. Specifically, autism, cerebral palsy, mental retardation, and attention deficit and hyperactivity disorder are reviewed. Ideal treatment for developmentally-disabled children with epilepsy entails maximal seizure control without any significant adverse effects from the anti-epileptic drugs and good quality of life. Antiepileptic drugs' cognitive and behavioral adverse effects tend to occur more frequently in these children. Careful selection of the appropriate medication and close monitoring for drug adverse effects is important. The specific adverse effects of the older and newer antiepileptic drugs are also reviewed. © 2010 Wiley-Liss, Inc. Dev Disabil Res Rev 2010;16:239–247.

Extensive efforts have been directed at using genome-wide association studies (GWAS) to identify the genes responsible for common metabolic and degenerative diseases, cancer, and aging, but with limited success. While environmental factors have been evoked to explain this conundrum, the nature of these environmental factors remains unexplained. The availability of and demands for energy constitute one of the most important aspects of the environment. The flow of energy through the cell is primarily mediated by the mitochondrion, which oxidizes reducing equivalents from hydrocarbons via acetyl-CoA, NADH + H⁺, and FADH₂ to generate ATP through oxidative phosphorylation (OXPHOS). The mitochondrial genome encompasses hundreds of nuclear DNA (nDNA)-encoded genes plus 37 mitochondrial DNA (mtDNA)-encoded genes. Although the mtDNA has a high mutation rate, only milder, potentially adaptive mutations are introduced into the population through female oocytes. In contrast, nDNA-encoded bioenergetic genes have a low mutation rate. However, their expression is modulated by histone phosphorylation and acetylation using mitochondrially-generated ATP and acetyl-CoA, which permits increased gene expression, growth, and reproduction when calories are abundant. Phosphorylation, acetylaton, and cellular redox state also regulate most signal transduction pathways and activities of multiple transcription factors. Thus, mtDNA mutations provide heritable and stable adaptation to regional differences while mitochondrially-mediated changes in the epigenome permit reversible modulation of gene expression in response to fluctuations in the energy environment. The most common genomic changes that interface with the environment and cause complex disease must, therefore, be mitochondrial and epigenomic in origin. © 2010 Wiley-Liss, Inc. Dev Disabil Res Rev 2010;16:114–119.

Mitochondrial respiratory chain disorders are a group of genetically and clinically heterogeneous disorders caused by the biochemical complexity of mitochondrial respiration and the fact that two genomes, one mitochondrial and one nuclear, encode the components of the respiratory chain. These disorders can manifest at birth or present later in life. They result, at least in part, in defective production of ATP. Typically, mitochondrial disorders affect tissues with high energetic demands such as skeletal muscle, cardiac muscle, and the central nervous system. Neurological dysfunction is the most frequent clinical presentation of these disorders. The central nervous system is highly dependent on oxidative metabolism, and particular mitochondrial disorders are accompanied by focal brain necrosis (Leigh disease), dementia, or static encephalopathy. Furthermore, many children with mitochondrial encephalomyopathies present with more subtle and indolent signs including focal cognitive deficits of memory, perception, and language. Some subjects with mitochondrial disorders may also exhibit nonverbal cognitive impairment, compromised visuospatial abilities, and short-term memory deficits associated with working memory that likely reflect defects in synaptic plasticity. Psychiatric features are found within the clinical spectrum of mitochondrial syndromes. It is increasingly recognized that mitochondrial dysfunction may be associated with neuropsychiatric abnormalities such as dementia, major depression, and bipolar disorder. Furthermore, several lines of evidence suggest that there is involvement of mitochondrial dysfunction in schizophrenia, including documented alterations in brain energy metabolism, electron transport chain activity, and expression of genes involved in mitochondrial function. The purpose of this review article is to summarize the psychiatric features observed in mitochondrial cytopathies and discuss possible mechanisms of dysfunctional cellular energy metabolism that underlie the pathophysiology of major subsets of psychiatric disorders. © 2010 Wiley-Liss, Inc. Dev Disabil Res Rev 2010;16:136–143.

In this review, we trace the origins and follow the development of mitochondrial medicine from the premolecular era (1962–1988) based on clinical clues, muscle morphology, and biochemistry into the molecular era that started in 1988 and is still advancing at a brisk pace. We have tried to stress conceptual advances, such as endosymbiosis, uniparental inheritance, intergenomic signaling and its defects, and mitochondrial dynamics. We hope that this historical review also provides an update on mitochondrial medicine, although we fully realize that the speed of progress in this area makes any such endeavor akin to writing on water. © 2010 Wiley-Liss, Inc. Dev Disabil Res Rev 2010;16:106–113.

The most common group of mitochondrial disease is due to mutations within the mitochondrial DNA polymerase, polymerase gamma 1 (POLG). This gene product is responsible for replication and repair of the small mitochondrial DNA genome. The structure-function relationship of this gene product produces a wide variety of diseases that at times, seems to defy the common perceptions of genetics. The unique features of mitochondrial physiology are in part responsible, but POLG structure and function add to the conundrum of how one gene product can demonstrate autosomal recessive and autosomal dominant transmission, while also being responsible for pharmacogenetic disease, and exhibiting strong gene-environment interactions. The wide spectrum of clinical manifestations of POLG disease can arise from infancy to old age. The modulation of clinical findings relate in part to the molecular architecture of the POLG protein. POLG has three distinct molecular domains: exonuclease, linker, and polymerase domains. Most of the mutations leading to dominant forms of POLG disease are located in the Polymerase domain. Mutations leading to recessive inheritance are distributed in all three domains of the gene. Environmental factors like valproic acid and infection can unmask POLG disease, causing it to occur earlier in life than when not exposed to these factors. Other drugs like nucleoside reverse transcriptase inhibitors can produce genotype-specific POLG pharmacogenetic disease. Our current state of POLG understanding cannot account for many features of POLG disease. There is no answer for why the same mutation can give rise to varying diseases, disease severity, and age of onset. We introduce the term Ecogenetics in the context these features of POLG disease, to emphasize the important interactions between genes and environment in determining the expression of mitochondrial disease. In this article, we identify some of the key features that will help the reader understand POLG pathophysiology. When possible, we also identify genotype-phenotype relationships, give clues for diagnosis, and summarize the major clinical phenotypes in the spectrum of POLG disease presenting from birth to old age. © 2010 Wiley-Liss, Inc. Dev Disabil Res Rev 2010;16:163–174.