Articles: phenotype.
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Comparative Study
Structural variation of chromosomes in autism spectrum disorder.
Structural variation (copy number variation [CNV] including deletion and duplication, translocation, inversion) of chromosomes has been identified in some individuals with autism spectrum disorder (ASD), but the full etiologic role is unknown. We performed genome-wide assessment for structural abnormalities in 427 unrelated ASD cases via single-nucleotide polymorphism microarrays and karyotyping. With microarrays, we discovered 277 unbalanced CNVs in 44% of ASD families not present in 500 controls (and re-examined in another 1152 controls). ⋯ Our most compelling result discovered CNV at 16p11.2 (p = 0.002) (with characteristics of a genomic disorder) at approximately 1% frequency. Some of the ASD regions were also common to mental retardation loci. Structural variants were found in sufficiently high frequency influencing ASD to suggest that cytogenetic and microarray analyses be considered in routine clinical workup.
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Ageing, or increased mortality with time, coupled with physiologic decline, is a nearly universal yet poorly understood biological phenomenon. Studies in model organisms suggest that two conserved pathways modulate longevity: DNA damage repair and Insulin/Igf1-like signalling. ⋯ Mice lacking SIRT6 develop a degenerative disorder that in some respects mimics models of accelerated ageing [Cell (2006) 124:315]. We discuss how sirtuins in general and SIRT6 specifically relate to other evolutionarily conserved pathways affecting ageing, and how SIRT6 might function to ensure organismal homeostasis and normal lifespan.
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Chronic nerve compression (CNC) injury initiates a series of pathological changes within the peripheral nerve at the site of injury. However, to date, little work has been performed to explore neuronal cell body responses to CNC injury. Here we show a preferential upregulation of growth-associated protein-43 (GAP-43) and enhanced Fluoro Ruby uptake by the small-diameter calcitonin gene-related protein (CGRP) and isolectin B4 (IB4)-positive neurons in the L4 and L5 ipsilateral dorsal root ganglion (DRG) 2 weeks and 1 month post injury. ⋯ Quantification of glial-derived neurotrophic factor (GDNF) protein revealed an upregulation in L4 and L5 DRG followed by a return to baseline values at later stages following injury. Upregulation of GDNF expression by Schwann cells was also readily apparent with both immunohistochemistry and Western blot analysis of 1 month compressed sciatic nerve specimens. Thus, CNC induces a phenotypic change in the DRG that appears to be temporally associated with increases in GDNF protein expression at and near the site of the compression injury in the nerve.
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Dev Disabil Res Rev · Jan 2008
ReviewCandidate genes and the behavioral phenotype in 22q11.2 deletion syndrome.
There is an overwhelming evidence that children and adults with 22q11.2 deletion syndrome (22q11.2DS) have a characteristic behavioral phenotype. In particular, there is a growing body of evidence that indicates an unequivocal association between 22q11.2DS and schizophrenia, especially in adulthood. Deletion of 22q11.2 is the third highest risk for the development of schizophrenia, with only a greater risk conferred by being the child of two parents with schizophrenia or the monozygotic co-twin of an affected individual. ⋯ In addition, variation in Gnb1L is associated with the presence of psychosis in males with 22q11.2DS. In mouse models of 22q11.2DS, haploinsufficiency of Tbx1 and Gnb1L is associated with reduced prepulse inhibition, a schizophrenia endophenotype. The study of 22q11.2DS provides an attractive model to increase our understanding of the development and pathogenesis of schizophrenia and other psychiatric disorders in 22q11.2DS and in wider population.
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The transforming growth factor beta-1 gene (TGFB1) is one of the most promising candidate genes for chronic obstructive pulmonary disease (COPD). Several case-control studies have been performed and generated inconsistent results. The possible reasons for these discrepancies include the diversity of ethnic populations and the heterogeneity of COPD, including emphysema and airway disease. We designed this study to investigate the association of single nucleotide polymorphisms (SNPs) of TGFB1 with the emphysema phenotype in the Japanese population. ⋯ One significant haplotype of TGFB1 is associated with the emphysema phenotype in the Japanese population. Two TGFB1 SNPs (rs1800469 and rs1982073) are associated with the severity of COPD in patients with emphysema phenotype.