A P Monaco

..Finally, communicating unexpected findings such as these back to families raises a number of ethical questions, which are discussed...

..A recent study of 517 ASD families implicated DOCK4 by single nucleotide polymorphism (SNP) association and a microdeletion in an affected sibling pair...

..Here we present an association study analysing the roles of four promising candidate genes - LRRTM1 (2p), LRRTM3 (10q), LRRN1 (3p) and LRRN3 (7q) - in order to identify common genetic risk factors underlying ASDs...

..We conclude that coding-region variants in FOXP2 do not underlie the AUTS1 linkage and that the gene is unlikely to play a role in autism or more common forms of language impairment...

..In contrast, SLI2 appeared to have influences on a selection of expressive and receptive language phenotypes in addition to non-word repetition, but did not show linkage to literacy phenotypes...

..We also discuss recent molecular genetic advances made in the study of generalized specific language impairment...

..We identified a gene in the CHAC critical region and found 16 different mutations in individuals with chorea-acanthocytosis. CHAC encodes an evolutionarily conserved protein that is probably involved in protein sorting...

..The analysis of these four genes strongly suggests that they do not play a major role in autism aetiology, and delineates our strategy to screen additional candidate genes in the AUTS1 locus...

..This study has excluded two plausible candidate genes from involvement in CHAC and has provided a solid platform for a positional cloning initiative...

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..These studies represent further steps toward the isolation of the first gene to be implicated in the development of speech and language...

..No significant evidence of association or linkage was found at any of the markers tested, indicating that the 5-HTT and the GABRB3 genes are unlikely to play a major role in the aetiology of autism in our family data set...

..In addition, we find association between reading-related measures and variants in CNTNAP2 and CMIP in the SLI families...

..Our findings suggest that FOXP2 is involved in the developmental process that culminates in speech and language...

..Protein sequence comparisons suggest that intramolecular duplications have played an important role in the evolution of this gene family...

..The liver cDNA clones have sequence identity with four genomic exons and the 3' untranslated region from an Xp21.3 cosmid thus indicating that this is the expressed GK gene which when deleted in patients gives rises to GK deficiency...

..Using a positional-cloning strategy, we identified in unrelated CMT4B patients mutations occurring in the gene MTMR2, encoding myotubularin-related protein-2, a dual specificity phosphatase (DSP)...

..The high linkage disequilibrium (LD) we observed across the DYX1C1 gene suggests that the association signal might not be refined by further genetic mapping...

..02). CONCLUSION: These data support the possibility of two discrete loci underlying linkage of autism to chromosome 7, and implicate possible parent of origin specific effects in the aetiology of autism...

..0001). Logistic regression analysis of SNP data across GRIN2A and ABAT showed a trend toward haplotypic differences between cases and controls...

..68) supported their heritability. These findings demonstrate the viability of this sample for QTL mapping, and will assist in the interpretation of any subsequent linkage findings in an ongoing genome scan...

..Investigation of mutations in these two genes in unrelated patients with either autism or multiple exostoses as well as linkage and association studies is needed to validate them as candidate genes...

..3 influences reading disability...

..Our study provides the first genetic evidence for a common basis of convulsive and choreoathetotic disorders and will help in the understanding and classification of paroxysmal neurological syndromes...

..Several of the other genes and ESTs located within the contig code for proteins implicated in normal brain development and function and are candidates for DYT3...

..In addition, the QTL effect may be largely limited to the severe range of reading disability...

..Several genes in this region of chromosome 12 which are potentially implicated in language impairment did not contain polymorphisms likely to be the causative mutation, which is as yet unknown...

..The identification and mapping of all these genes will make them useful tools for mutation detection in neurological as well as other human diseases...

..Our results provide evidence that a specific mutation in Cx26 can impair epidermal differentiation, as well as inner ear function...

..Our results suggest that loss-of-function mutations in MTMR2 are preferentially associated with the CMT4B phenotype...

..Our findings provide the first evidence for a defect in an EDC gene in human disease, and disclose novel insights into perturbations of cornified cell envelope formation...

..Genomic localization and expression patterns would suggest that these newly assigned cDNAs represent potential candidate genes for the 5q- syndrome...

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..Therefore, the protein sequence encoded by exon 10 may be responsible for this differential localization and both isoforms may be required for comprehensive transport of copper within the cell...

..This is the first report of QTL-based genome-wide scanning for a human cognitive trait...

..The results of recent genetic linkage and candidate gene studies are reviewed in relation to the challenge of clinical and genetic heterogeneity, and prospects for the future of genetic research in autism are considered...

..Two of the regions highlighted in the present study, 2q24 and 16p13, coincided with the top linkage peaks reported by a recent genome-scan study of autistic sib pairs...

..Large insert libraries are constructed by size fractionating large DNA embedded in agarose and protecting DNA from degradation with polyamines...

..This unit provides a simple protocol for generating a partial-digest sublibrary of yeast DNA containing a YAC of interest...

..The analysis of RELN suggests that it probably does not play a major role in autism aetiology, although further analysis of several missense mutations is warranted in additional affected individuals...

..Targeted genotyping of candidate gene variants in this large multiplex family sample will then be performed to confirm association with autism...

..Similarities between the genomic structure suggest that utrophin and dystrophin arose through an ancient duplication event involving a large region of genomic DNA...

..A long-range PCR assay was used to confirm the existence of the deletion. We also show the breakpoint identification and large-scale characterisation of this CNV in a normal human sample set...

..LRRTM1 is a candidate gene for involvement in several common neurodevelopmental disorders, and may have played a role in human cognitive and behavioral evolution...

..The CHAC protein product, chorein, appears to have a certain tolerance to amino-acid substitutions since only two out of nine substitutions described here appear to be pathogenic...

..13. Relative hand skill therefore is probably a complex multifactorial phenotype with a heterogeneous background, but nevertheless is amenable to QTL-based gene-mapping approaches...

..This endeavor will be crucial for gaining insight into the role of FOXP2 in human cognition...

..Rare mutations affecting the FOXP2 transcription factor cause a monogenic speech and language disorder. We hypothesized that neural pathways downstream of FOXP2 influence more common phenotypes, such as specific language impairment...

..Finally, after computer analysis of the 33 ESTs assigned to the 2-Mb interval, we demonstrated that 21 different transcripts as well as 3 known genes might represent potential candidates for the disease...

..The missense mutations in EXT1 and EXT2 may pinpoint crucial domains in both proteins and therefore give clues for the understanding of the pathophysiology of this skeletal disorder...

..Our study thus pinpoints a common variant as altering the function of a dyslexia candidate gene and provides an illustrative example of the strategic approach needed to dissect the molecular basis of complex genetic traits...

..Identifying those cognitive deficits that work best as indices of heritable phenotypes will help us to uncover the aetiology of developmental disorders...

..In the current study, the authors tested whether the KIAA0319 gene influences reading skills in the general population, rather than having an effect restricted to reading disability...

..Our study outlines the approach necessary for the identification of genetic variants causing dyslexia susceptibility in an epidemiological population of dyslexics...

..Many children acquire language so smoothly that it appears to be an innate ability. If this is true, then it should be possible to identify genes that underlie variations in linguistic abilities...

..The molecular genetic approach has potential for dissecting neurological pathways underlying speech and language disorders, but such investigations are only just beginning...

..We discuss how characterization of these genes, and the pathways in which they are involved, may enhance our understanding of language disorders and improve our understanding of the biological foundations of language acquisition...

..02). The previously reported positive association of rs1858830 failed to replicate in this study. Overall, our findings provide further evidence that MET may play a role in autism susceptibility...

..Nevertheless, it remains possible that variants in the flanking genes may underlie evidence of linkage at this locus...

..This technique was found to be sensitive with a detection rate of 100% regarding heterozygote detection for EXT mutation scanning. Furthermore, this technique has a very high throughput and is very cost-effective...

..The linkages may be due to a single maternally imprinted influence on lateralized brain development that contains common functional polymorphisms...

..Further studies should aim to characterise the precise phenotypic range of this CNV and may lead to the discovery of genetic or environmental modifiers...

..This review focuses on recent molecular investigations to identify susceptibility loci implicated in autistic disorder...

..These findings provide strong evidence for the involvement of a single locus for CHAC and are the first step in positional cloning of the disease gene...

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..Our results demonstrate that mutations in ATP2A2 cause DD and disclose a role for this pump in a Ca(2+)-signalling pathway regulating cell-to-cell adhesion and differentiation of the epidermis...

..This work therefore implicates CMIP and ATP2C2 in the etiology of SLI and provides molecular evidence for the importance of phonological short-term memory in language acquisition...

..This study comprises a significant step toward identifying the genetic substrates underlying synesthesia, with important implications for our understanding of the role of genes in human cognition and perception...

..However, this was also found in a random control sample. Analyses of non-coding SNP changes did not find any correlation with affection status. We conclude that FOXP1 mutations are unlikely to represent a major cause of DVD...

..2 down-regulates the KIAA0319 gene which is required for neuronal migration during the formation of the cerebral neocortex...

..The approach employed here may aid positional cloning of susceptibility genes in a wide spectrum of complex traits...

..No CNVs or SNP associations were found within the sample set, although sequencing of the gene was not performed. Our data suggest that SHANK3 deletions may be limited to lower functioning individuals with autism...

..These findings should lead to more accurate prenatal diagnosis of this severe disease and a better understanding of the cellular homeostasis of essential heavy metals...

..The extensive interfamilial and intrafamilial phenotypic variability observed suggests that modifying genes and/or environmental factors may greatly influence the clinical features of this disease...

..008). Our results strengthen the case for a more detailed study of the role of RELN and GRIK2 in autism susceptibility, as well as identifying two new potential candidate genes, MKL2 and SND1...

..These results suggest the surface expression of KIAA0319 is regulated by endocytosis, supporting the idea that the internalization and recycling of the protein may be involved in fine tuning its role in neuronal migration...

..These genomic regions contain tens or hundreds of candidate genes, and studies aimed at the identification of the specific causal genetic variants are underway...

..Association was also detected for several polymorphisms in the promoter and untranslated region of NRCAM, suggesting that alterations in expression of this gene may be linked to autism susceptibility...

..A similar RT-PCR analysis performed in mouse and rat adult brains showed that only some of the alternative splicing variants are equivalent to those found in the human gene...

..Functional studies of these genes are offering new insights about the biological mechanisms underlying the development of dyslexia and, in general, of cognition...

..Therefore, this detailed integrated physical, genetic, and partial transcript map provides an important resource for the isolation of the DD gene and, possibly, other disease genes...

..MAGE-Xp is located in the 160-kb critical interval defined for the locus involved in sex determination within Xp21 and is 50 kb distal to the DAX-1 gene, which is responsible for X-chromosome-linked adrenal hypoplasia congenita...

..The deletion breakpoint PCR described here will enable rapid identification of both homozygous and heterozygous carriers of EX70_EX73del...

..Finally, the authors found no evidence that reading disability and/or low general cognitive ability were associated with ambidexterity...

..A recent study using the PPL statistical framework identified a novel region of genetic linkage on chromosome 16q21 that is limited to ASD families with LD...

..However, chorein expression was absent or noticeably reduced in ChAc patient cells, but not McLeod syndrome and Huntington's disease cells. This suggests that loss of chorein expression is a diagnostic feature of ChAc...

..Our study failed to reveal any significant association for the SNPs tested at either locus, suggesting that these variants are unlikely to play a major role in genetic susceptibility to autism in our sample...

..Choreoacanthocytosis (CHAC) is a slowly progressive multisystem disorder with involuntary movements, cognitive decline, behavioral changes, seizures, and polyneuropathy caused by mutations in the VPS13A gene...

..Neurexins team with previously implicated neuroligins for glutamatergic synaptogenesis, highlighting glutamate-related genes as promising candidates for contributing to ASDs...

..Here we show that human FOXP2 contains changes in amino-acid coding and a pattern of nucleotide polymorphism, which strongly suggest that this gene has been the target of selection during recent human evolution...

..Overall, this study provides support for the hypothesis that impairments in sequencing of movement and procedural learning might be central to the FOXP2-related speech and language disorder...

..Although the clinical presentation was variable, the genetic studies on these three Saudi Arabian families with chorea-acanthocytosis provide strong evidence for a genetic locus for chorea-acanthocytosis at chromosome 9q21...

..Mutations in VPS13A or GNA14 or both may be associated with clinical features of temporal lobe epilepsy...

..These findings suggest that variations in a gene on 16p13 may contribute to common deficits found in both ADHD and autism...

..KIAA0319-deletion proteins lacking the TM domain were also secreted. These results suggest that KIAA0319 could be involved not only in cell-cell interactions, but also in signalling...

..Interestingly, both regions, as well as 5p13, have been highlighted in genomewide scans for autism...

..5, with some areas of enriched expression. At E14.5, Mtmr2 mRNA was more abundant in the peripheral nervous system, including in dorsal root ganglia and spinal roots...