ABSTRACT
Despite very strong evidence for a genetic basis for the susceptibility to develop Gilles de la Tourette syndrome (GTS), as of this date, a gene contributing to GTS has not convincingly been identified. The failure to identify genes contributing to GTS may be the result of multiple factors including a more complex mode of inheritance than previously suspected, locus heterogeneity with a number of risk genes located at different chromosomal locations, and uncertainties about how best to define the phenotype for genetic studies. Chromosomal abnormalities have been reported in isolated cases of GTS, but thus far, genes identified at breakpoints in these chromosomes do not appear to contribute to a large percentage of families with GTS. Results from several genome scans have pointed to the likely locations of GTS susceptibility genes and these regions are currently under study, with the goal of narrowing these regions for gene identification. Alternative phenotypes and statistical methods are being used in the linkage analyses to further refine the search for genes and these approaches appear promising. While it is difficult for an animal model to fully represent the complex phenotype of GTS, some progress has been made in the understanding of stereotypic movements, hyperlocomotion, and excessive grooming in experimental animal models. Such models can therefore provide important
MD: KURLAN, JOB: 03329, PAGE:
insights as to the types of genes that are likely to contribute toGTS, whichwill help to guide future genetic studies.
