Publications by authors named "Gabrielle Barnby"

4 Publications

  • Page 1 of 1

Linkage and candidate gene studies of autism spectrum disorders in European populations.

Eur J Hum Genet 2010 Sep 5;18(9):1013-9. Epub 2010 May 5.

The Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK.

Over the past decade, research on the genetic variants underlying susceptibility to autism and autism spectrum disorders (ASDs) has focused on linkage and candidate gene studies. This research has implicated various chromosomal loci and genes. Candidate gene studies have proven to be particularly intractable, with many studies failing to replicate previously reported associations. In this paper, we investigate previously implicated genomic regions for a role in ASD susceptibility, using four cohorts of European ancestry. Initially, a 384 SNP Illumina GoldenGate array was used to examine linkage at six previously implicated loci. We identify linkage approaching genome-wide suggestive levels on chromosome 2 (rs2885116, MLOD=1.89). Association analysis showed significant associations in MKL2 with ASD (rs756472, P=4.31 x 10(-5)) and between SND1 and strict autism (rs1881084, P=7.76 x 10(-5)) in the Finnish and Northern Dutch populations, respectively. Subsequently, we used a second 384 SNP Illumina GoldenGate array to examine the association in seven candidate genes, and evidence for association was found in RELN (rs362780, P=0.00165). Further increasing the sample size strengthened the association with RELN (rs362780, P=0.001) and produced a second significant result in GRIK2 (rs2518261, P=0.008). 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.
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http://dx.doi.org/10.1038/ejhg.2010.69DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2987412PMC
September 2010

Mapping autism risk loci using genetic linkage and chromosomal rearrangements.

Nat Genet 2007 Mar 18;39(3):319-28. Epub 2007 Feb 18.

Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario L8N 3Z5, Canada.

Autism spectrum disorders (ASDs) are common, heritable neurodevelopmental conditions. The genetic architecture of ASDs is complex, requiring large samples to overcome heterogeneity. Here we broaden coverage and sample size relative to other studies of ASDs by using Affymetrix 10K SNP arrays and 1,181 [corrected] families with at least two affected individuals, performing the largest linkage scan to date while also analyzing copy number variation in these families. Linkage and copy number variation analyses implicate chromosome 11p12-p13 and neurexins, respectively, among other candidate loci. Neurexins team with previously implicated neuroligins for glutamatergic synaptogenesis, highlighting glutamate-related genes as promising candidates for contributing to ASDs.
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http://dx.doi.org/10.1038/ng1985DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4867008PMC
March 2007

Candidate-gene screening and association analysis at the autism-susceptibility locus on chromosome 16p: evidence of association at GRIN2A and ABAT.

Am J Hum Genet 2005 Jun 13;76(6):950-66. Epub 2005 Apr 13.

Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.

Autism is a highly heritable neurodevelopmental disorder whose underlying genetic causes have yet to be identified. To date, there have been eight genome screens for autism, two of which identified a putative susceptibility locus on chromosome 16p. In the present study, 10 positional candidate genes that map to 16p11-13 were examined for coding variants: A2BP1, ABAT, BFAR, CREBBP, EMP2, GRIN2A, MRTF-B, SSTR5, TBX6, and UBN1. Screening of all coding and regulatory regions by denaturing high-performance liquid chromatography identified seven nonsynonymous changes. Five of these mutations were found to cosegregate with autism, but the mutations are not predicted to have deleterious effects on protein structure and are unlikely to represent significant etiological variants. Selected variants from candidate genes were genotyped in the entire International Molecular Genetics Study of Autism Consortium collection of 239 multiplex families and were tested for association with autism by use of the pedigree disequilibrium test. Additionally, genotype frequencies were compared between 239 unrelated affected individuals and 192 controls. Patterns of linkage disequilibrium were investigated, and the transmission of haplotypes across candidate genes was tested for association. Evidence of single-marker association was found for variants in ABAT, CREBBP, and GRIN2A. Within these genes, 12 single-nucleotide polymorphisms (SNPs) were subsequently genotyped in 91 autism trios (one affected individual and two unaffected parents), and the association was replicated within GRIN2A (Fisher's exact test, P<.0001). Logistic regression analysis of SNP data across GRIN2A and ABAT showed a trend toward haplotypic differences between cases and controls.
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http://dx.doi.org/10.1086/430454DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1196454PMC
June 2005

Mutation screening and association analysis of six candidate genes for autism on chromosome 7q.

Eur J Hum Genet 2005 Feb;13(2):198-207

The Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.

Genetic studies have provided evidence for an autism susceptibility locus (AUTS1) on chromosome 7q. Screening for mutations in six genes mapping to 7q, CUTL1, SRPK2, SYPL, LAMB1, NRCAM and PTPRZ1 in 48 unrelated individuals with autism led to the identification of several new coding variants in the genes CUTL1, LAMB1 and PTPRZ1. Analysis of genetic variants provided evidence for association with autism for one of the new missense changes identified in LAMB1; this effect was stronger in a subgroup of affected male sibling pair families, implying a possible specific sex-related effect for this variant. 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.
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http://dx.doi.org/10.1038/sj.ejhg.5201315DOI Listing
February 2005
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