Project description:This SuperSeries is composed of the following subset Series: GSE23572: Custom array CGH validation of de novo CNVs in asthma samples GSE23575: Custom array CGH validation of de novo CNVs in CEU HapMap samples Refer to individual Series
Project description:This is the validation data for candidate de novo CNV calls made in the CEU Hapmap by Itsara et al., Genome Research 2010. In this study, de novo CNV calls were initially made with Illumina 1M SNP arrays. Validation of CNV calls was performed with Nimblegen custom array CGH using the extended CEPH pedigrees. A truly de novo CNV would be unobserved in the first generation (CEU trio parents), validated in the second generation (CEU trio children), and assuming no selective effects, transmitted to approximately half of the individuals in the third generation. We attempted validation of 4 de novo CNVs in 3 extended CEPH pedigrees: 1358, 1408, and 1459.
Project description:This is the validation data for candidate de novo CNV calls made in the CEU Hapmap by Itsara et al., Genome Research 2010. In this study, de novo CNV calls were initially made with Illumina 1M SNP arrays. Validation of CNV calls was performed with Nimblegen custom array CGH using the extended CEPH pedigrees. A truly de novo CNV would be unobserved in the first generation (CEU trio parents), validated in the second generation (CEU trio children), and assuming no selective effects, transmitted to approximately half of the individuals in the third generation. We attempted validation of 4 de novo CNVs in 3 extended CEPH pedigrees: 1358, 1408, and 1459. 12 samples were hybridized in each of the three pedigrees (36 samples total) against a previously well-characterized reference (GM15510; see Tuzun et al., Nat Genet 2005).
Project description:This is the validation data for candidate de novo CNV calls made in the asthma trios by Itsara et al., Genome Research 2010. In this study, de novo CNV calls in the asthma data set were initially made with Illumina 550K SNP arrays. Validation was performed with custom Nimblegen array CGH for which DNA was available. de novo CNVs would be expected to validate in the child of each trio tested, and not be detected in either parent.
Project description:This is the validation data for candidate de novo CNV calls made in the asthma trios by Itsara et al., Genome Research 2010. In this study, de novo CNV calls in the asthma data set were initially made with Illumina 550K SNP arrays. Validation was performed with custom Nimblegen array CGH for which DNA was available. de novo CNVs would be expected to validate in the child of each trio tested, and not be detected in either parent. We attempted to validate 9 de novo CNVs in the same number of trios. In 3 cases, paternal DNA was not available leaving a total of 24 distinct samples for hybridization. All samples were hybridized against a previously well-characterized reference (NA15510; see Tuzun et al., Nat Genet 2005).
Project description:An increased rate of de novo copy number variants (CNVs) has been found in schizophrenia (SZ), autism and developmental delay. An increased rate has also been reported in bipolar affective disorder (BD). Here, in a larger BD sample, we aimed to replicate these findings and compare de novo CNVs between SZ and BD. We used Illumina microarrays to genotype 368 BD probands, 76 SZ probands and all their parents. Copy number variants were called by PennCNV and filtered for frequency (<1%) and size (>10 kb). Putative de novo CNVs were validated with the z-score algorithm, manual inspection of log R ratios (LRR) and qPCR probes. We found 15 de novo CNVs in BD (4.1% rate) and 6 in SZ (7.9% rate). Combining results with previous studies and using a cut-off of >100 kb, the rate of de novo CNVs in BD was intermediate between controls and SZ: 1.5% in controls, 2.2% in BD and 4.3% in SZ. Only the differences between SZ and BD and SZ and controls were significant. The median size of de novo CNVs in BD (448 kb) was also intermediate between SZ (613 kb) and controls (338 kb), but only the comparison between SZ and controls was significant. Only one de novo CNV in BD was in a confirmed SZ locus (16p11.2). Sporadic or early onset cases were not more likely to have de novo CNVs. We conclude that de novo CNVs play a smaller role in BD compared with SZ. Patients with a positive family history can also harbour de novo mutations.
Project description:The HapMap project has facilitated the selection of tagging single nucleotide polymorphisms (tagSNPs) for genome-wide association studies (GWAS) under the assumption that linkage disequilibrium (LD) in the HapMap populations is similar to the populations under investigation. Earlier reports support this assumption, although in most of these studies only a few loci were evaluated. We compared pair-wise LD and LD block structure across autosomes between the Dutch population and the CEU-HapMap reference panel. The impact of sampling distribution on the estimation of LD blocks was studied by bootstrapping. A high Pearson correlation (genome-wide; 0.93) between pair-wise r(2) for the Dutch and the CEU populations was found, indicating that tagSNPs from the CEU-HapMap panel capture common variation in the Dutch population. However, some genomic regions exhibited, significantly lower correlation than the genome-wide estimate. This might decrease the validity of HapMap tagSNPs in these regions and the power of GWAS. The LD block structure differed considerably between the Dutch and CEU-HapMap populations. This was not explained by demographic differences between the CEU and Dutch samples, as testing for population stratification was not significant. We also found that sampling variation had a large effect on the estimation of LD blocks, as shown by the bootstrapping analysis. Thus, in small samples, most of the observed differences in LD blocks between populations are most likely the result of sampling variation. This poor concordance in LD block structure suggests that large samples are required for robust estimations of local LD block structure in populations.
Project description:While it is known that rare copy-number variants (CNVs) contribute to risk for some neuropsychiatric disorders, the role of CNVs in bipolar disorder is unclear. Here, we reasoned that a contribution of CNVs to mood disorders might be most evident for de novo mutations. We performed a genome-wide analysis of de novo CNVs in a cohort of 788 trios. Diagnoses of offspring included bipolar disorder (n = 185), schizophrenia (n = 177), and healthy controls (n = 426). Frequencies of de novo CNVs were significantly higher in bipolar disorder as compared with controls (OR = 4.8 [1.4,16.0], p = 0.009). De novo CNVs were particularly enriched among cases with an age at onset younger than 18 (OR = 6.3 [1.7,22.6], p = 0.006). We also confirmed a significant enrichment of de novo CNVs in schizophrenia (OR = 5.0 [1.5,16.8], p = 0.007). Our results suggest that rare spontaneous mutations are an important contributor to risk for bipolar disorder and other major neuropsychiatric diseases.