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Researchers used data from the Avon Longitudinal Study of Parents and Children to identify maternal psychological risk factors during pregnancy that increase the risk of tic disorders in offspring \citep{Ben_Shlomo_2015}. The Avon Longitudinal Study is an ongoing, prospective, pre-birth cohort study of all children born in Avon, United Kingdom, between April 1, 1991, and December 31, 1992. Maternal questionnaires were administered throughout pregnancy and they completed questionnaires about themselves and their children's development every 6 months from the child's birth to age 7 and then every year thereafter. In the final multivariate model, chronic maternal anxiety, evident both before and after parturition, was associated with TS or chronic tic disorder in their offspring. The authors suggest that this association may reflect shared genetic susceptibility or prenatal exposure.  |**Title** | **Comment** |  |:----------|:------------|  | GWAS in TS/CTD and OCD \citep{25158072} | *"METHOD: The authors conducted a GWAS [genome-wide association study] in 2,723 cases (1,310 with OCD, 834 with Tourette's syndrome, 579 with OCD plus Tourette's syndrome/chronic tics), 5,667 ancestry-matched controls, and 290 OCD parent-child trios. GWAS summary statistics were examined for enrichment of functional variants associated with gene expression levels in brain regions. Polygenic score analyses were conducted to investigate the genetic architecture within and across the two disorders. ... CONCLUSIONS: Previous work has shown that Tourette's syndrome and OCD have some degree of shared genetic variation. However, the data from this study suggest that there are also distinct components to the genetic architectures of these two disorders. Furthermore, OCD with co-occurring Tourette's syndrome/chronic tics may have different underlying genetic susceptibility compared with OCD alone."* \citep{25158072} |  | Astrocyte metabolism in TS \citep{25735483} | A collaborative genetic study shows association of TS with genes expressed in astrocytes, especially with 33 genes involved in glycolosis and glutamate metabolism. The results not only narrow the hunt for genes that may cause TS, they encourage future electrophysiological, imaging and pharmacological studies in a new direction. |   | AADAC gene deletion \citep{26444075} | This large collaborative group studied _AADAC_, the gene encoding arylacetamide deacetylase, in which microdeletions had been identified in a previous, smaller copy number variation study. "In the Danish cohort, we identified eight patients with overlapping deletions of _AADAC_. Investigation of the additional five countries showed a significant association between the _AADAC_ deletion and GTS, and a final meta-analysis confirmed the significant association (\( p = 4.4 \times 10^{−4} \)); odds ratio = 1.9; 95% confidence interval = 1.33–2.71). Furthermore, RNA in situ hybridization and reverse transcription-polymerase chain reaction studies revealed that _AADAC_ is expressed in several brain regions previously implicated in GTS pathology." |  | NMDA receptor gene polymorphism in Han Chinese \citep{26321256} | This relatively small sample provided preliminary evidence for linkage of TS and the gene for the NMDA receptor 2B subunit. |