Project description:Autism spectrum disorders (ASD) are common, heritable neurodevelopmental conditions. The genetic architecture of ASD is complex, requiring large samples to overcome heterogeneity. Here we broaden coverage and sample size relative to other studies of ASD by using Affymetrix 10K single nucleotide polymorphism (SNP) arrays and 1168 families with = 2 affected individuals to perform the largest linkage scan to date, while also analyzing copy number variation (CNV) in these families. Linkage and CNV analyses implicate chromosome 11p12-p13 and neurexins, respectively, amongst other candidate loci. Neurexins team with previously-implicated neuroligins for glutamatergic synaptogenesis, highlighting glutamate-related genes as promising candidates for ASD. Keywords: Autism spectrum disorder, Affymetrix SNP genotyping, linkage analysis, copy number analysis, chromosomal rearrangements.
Project description:The Gvh1 gene loci was identified by linkage analysis in a segregating mouse backcross. Congenic mapping has refined the linked loci to a 1.3 Mb interval on mouse Chr16 (39.41 - 40.71Mb) that constitutes the congenic interval in the B10.BALB-16.C2A mouse line. Gene expression microarray was performed to characterize downstream transcripitional regulation by risk variants in the congenic interval;.
Project description:Chromosomal abnormalities have been identified in some individuals with Autism Spectrum Disorder (ASD), but their full etiologic role is unknown. Submicroscopic copy number variation (CNV) represents a considerable source of genetic variation in the human genome that contributes to phenotypic differences and disease susceptibility. To explore the contribution CNV imbalances in ASD, we genotyped unrelated ASD index cases using the Affymetrix GeneChip® 500K single nucleotide polymorphism (SNP) mapping array. Keywords: Whole Genome Mapping SNP Genotyping Array
Project description:The integration of the results of QTL fine-mapping with microarray expression data offers a promising tool for understanding the genetic mechanisms influencing complex traits as fatty acid composition in pigs. The expression level of each probe may be treated as a quantitative trait and the marker genotypes used to map loci with regulatory effect on the gene expression level (eQTL) According to our previous linkage results, we carry out an eQTL scan focused on chromosomal regions showing tissue-consistent effects on fatty acids with Longissimus dorsi gene expression data in order to detect potentional candidate genes underlying the QTL previously detected.
Project description:The Gvh1 gene loci was identified by linkage analysis in a segregating mouse backcross. Congenic mapping has refined the linked loci to a 1.3 Mb interval on mouse Chr16 (39.41 - 40.71Mb) that constitutes the congenic interval in the B10.BALB-16.C2A mouse line. Gene expression microarray was performed to characterize downstream transcripitional regulation by risk variants in the congenic interval;. Each individual sample was pooled from 3 mice and performed in triplicate for each experimental group (TBI 900 cGy versus 0 cGy) for statistical analysis.
Project description:Despite lingering genotoxicity concerns, CRISPR-based genome editing has progressively entered the gene therapy field. Here we report that interactions between nucleotide sequences that are localized on the same chromosome and exhibit a high degree of homology contribute substantially to post-editing chromosomal rearrangements. We successfully employed corrective editing strategies at the NCF1 gene, as well as at the colocalized pseudogenes, NCF1B and NCF1C, in a human cell line model of p47phox-deficient chronic granulomatous disease and in patient-derived human hematopoietic stem cells. Upon genetic manipulation, an improved droplet digital PCR-based method identified cells with altered copy numbers, spanning megabases from the edited loci. We attributed the high aberration frequency to the interaction between repetitive sequences and their predisposition to recombination events. Our findings emphasize the need for careful evaluation of the target-specific genomic context, such as the presence of homologous regions, whose genome instability can constitute a risk factor for chromosomal rearrangements upon genome editing.
Project description:The main genetic factors for familial melanoma remain unknown in more than 75% of families. CDKN2A is mutated in around 20% of melanoma-prone families. Other high-risk melanoma susceptibility genes explain less than 3% of families studied to date. We performed the first genome-wide linkage analysis in CDKN2A-negative Spanish melanoma-prone families to identify novel melanoma susceptibility loci. We included 68 individuals from 2, 3 and 6 families with 2, 3 and at least 4 melanoma cases. We detected a locus with significant linkage evidence at 11q14.1-q14.3, with a maximum het-TLOD of 3.449 (rs12285365:A>G), using evidence from multiple pedigrees. The genes contained by the subregion with the strongest linkage evidence were: DLG2, PRSS23, FZD4 and TMEM135. We also detected several regions with suggestive linkage evidence (TLOD>1.9) (1q, 6p, 7p, 11q, 12p, 13q) including the region previously detected in melanoma-prone families from Sweden at 3q29. The family specific analysis revealed three loci with suggestive linkage evidence for family #1: 1q31.1-q32.1 (max. TLOD 2.447), 6p24.3-p22.3 (max. TLOD 2.409) and 11q13.3-q21 (max. TLOD 2.654). Future next generation sequencing studies of these regions may allow the identification of new melanoma susceptibility genetic factors.
Project description:The main genetic factors for familial melanoma remain unknown in more than 75% of families. CDKN2A is mutated in around 20% of melanoma-prone families. Other high-risk melanoma susceptibility genes explain less than 3% of families studied to date. We performed the first genome-wide linkage analysis in CDKN2A-negative Spanish melanoma-prone families to identify novel melanoma susceptibility loci. We included 68 individuals from 2, 3 and 6 families with 2, 3 and at least 4 melanoma cases. We detected a locus with significant linkage evidence at 11q14.1-q14.3, with a maximum het-TLOD of 3.449 (rs12285365:A>G), using evidence from multiple pedigrees. The genes contained by the subregion with the strongest linkage evidence were: DLG2, PRSS23, FZD4 and TMEM135. We also detected several regions with suggestive linkage evidence (TLOD>1.9) (1q, 6p, 7p, 11q, 12p, 13q) including the region previously detected in melanoma-prone families from Sweden at 3q29. The family specific analysis revealed three loci with suggestive linkage evidence for family #1: 1q31.1-q32.1 (max. TLOD 2.447), 6p24.3-p22.3 (max. TLOD 2.409) and 11q13.3-q21 (max. TLOD 2.654). Future next generation sequencing studies of these regions may allow the identification of new melanoma susceptibility genetic factors.
Project description:Coordinated regulation of gene expression levels across a series of experimental conditions provides valuable information about the functions of correlated transcripts. To map gene regulatory pathways, we used microarray-derived gene expression measurements in 60 individuals of an F2 sample segregating for diabetes. We performed correlation analysis among ~40,000 expression traits. By combining correlation among expression traits and linkage mapping information, we were able to identify regulatory networks, make functional predictions to uncharacterized genes, and characterize novel members of known pathways. Using 36 seed traits, we found evidence of coordinate regulation of 160 G-protein coupled receptor (GPCR) pathway expression traits. Of the 160 traits, 50 had their major LOD peak within 8 cM of a locus on chromosome 2, and 81 others had a secondary peak in this region. A previously uncharacterized Riken cDNA clone, which showed strong correlation with stearoyl CoA desaturase 1 expression, was experimentally validated to be responsive to conditions that regulate lipid metabolism. Using linkage mapping, we identified multiple genes whose expression is under the control of transcription regulatory loci. Trait-correlation combined with linkage mapping can reveal regulatory networks that would otherwise be missed if we only studied mRNA traits with statistically significant linkages in this small cross. The combined analysis is more sensitive compared with linkage mapping only. References: Kendziorski C., M. Chen, M. Yuan, H. Lan, and A.D. Attie. Statistical Methods for Expression Quantitative Trait Loci (eQTL) Mapping. Biometrics, to appear, 2005. Lan H, Chen M, Flowers JB, Yandell BS, Stapleton DS, et al. (2006) Combined Expression Trait Correlations and Expression Quantitative Trait Locus Mapping. PLoS Genet 2(1): e6. Keywords: Genetics of gene expression
Project description:The integration of the results of QTL fine-mapping with microarray expression data offers a promising tool for understanding the genetic mechanisms influencing complex traits as fatty acid composition in pigs. The expression level of each probe may be treated as a quantitative trait and the marker genotypes used to map loci with regulatory effect on the gene expression level (eQTL) According to our previous linkage results, we carry out an eQTL scan focused on chromosomal regions showing tissue-consistent effects on fatty acids with Longissimus dorsi gene expression data in order to detect potentional candidate genes underlying the QTL previously detected. 102 IberianxLandrace backcross pigs were selected for RNA extraction and hybridization on Affymetrix microarrays. An eQTL scan was carried out with the data of 470 probes of the microarray taking into account they were related with fatty acid metabolism