Tourette syndrome (TS) is a neuropsychiatric disorder with a strong genetic component. However, the genetic architecture of TS remains uncertain. Copy number variation (CNV) has been shown to contribute to the genetic make-up of several neurodevelopmental conditions, including schizophrenia and autism. Here we describe CNV calls using SNP chip genotype data from an initial sample of 210 TS cases and 285 controls ascertained in two Latin American populations. After extensive quality control, we found that cases (N = 179) have a significant excess (P = 0.006) of large CNV (>500 kb) calls compared to controls (N = 234). Amongst 24 large CNVs seen only in the cases, we observed four duplications of the COL8A1 gene region. We also found two cases with ∼400kb deletions involving NRXN1, a gene previously implicated in neurodevelopmental disorders, including TS. Follow-up using multiplex ligation-dependent probe amplification (and including 53 more TS cases) validated the CNV calls and identified additional patients with rearrangements in COL8A1 and NRXN1, but none in controls. Examination of available parents indicates that two out of three NRXN1 deletions detected in the TS cases are de-novo mutations. Our results are consistent with the proposal that rare CNVs play a role in TS aetiology and suggest a possible role for rearrangements in the COL8A1 and NRXN1 gene regions.

Gilles de la Tourette Syndrome (GTS) is a chronic neuropsychiatric disorder characterized by motor and vocal tics. Epidemiological evidence supports the importance of genetic factors in disease susceptibility, whereas pharmacological and neuroimaging studies have suggested a defect in the dopamine system. The dopamine receptor D2 gene (DRD2) has been reported to be associated with GTS and related phenotypes. Here, we evaluate genetic association between DRD2 and GTS in a sample from a South American population isolate (Antioquia, Colombia). We genotyped nine single nucleotide polymorphisms (SNPs) across the DRD2 gene region in 69 GTS patients and their nuclear families and carried out both SNP and haplotype-based transmission distortion analysis. Evidence for association was found for three SNPs (rs6279, rs1079597 and rs4648318) and a five marker-haplotype comprising both rs6279 and rs1079597. Our findings replicate the association of DRD2 and GTS, and are consistent with the proposed connection between the dopamine system and this complex neuropsychiatric disease.

This study analyzes the effectof changes in corporate controlon the way shareholdersbenefit from the announcements of selling and buying airlines, thus contributing to the literature on mergers and acquisitions (M&As) in emerging markets. Using a methodologyof event study, including GARCH and OLS models, we find evidence that some selling companies obtain abnormal returns that are statisticallysignificant after the announcement of the M&A. However, when the merger is not strategic, the companies present statisticallysignificant negative abnormal returns. The resultsare not conclusive when analyzing the effecton the valueof the buying companies.

Construction prices are lower in developing countries in ICP 2005, which has raised these countries' capital/output ratio in Penn World Tables 7 and 8 and affected growth analyses. We estimate the Colombia/U.S. price ratio for office and apartment buildings in 2005 as a test of the validity of the ICP 2005 methodology for estimating these prices. Our estimate of the Colombia/U.S. price ratio is almost twice the ICP 2005 estimate. We confirm the validity of our results by estimating the cost of constructing office and apartment buildings using 2005 prices for construction materials, equipment, and labor in both countries. JEL Codes: E30, O47

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