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The genetic architecture of TS is largely unknown. Geneticists agree that TS is indeed a hereditary or genetic condition, meaning it is passed down from parent to child. Beyond that, little is understood about the topic.
Researchers have long sought to understand which genes specifically cause TS. Scientists continue to make strides in answering this question with the latest breakthrough coming from a team researchers from Massachusetts General Hospital and the University of Chicago.
These scientists published a report in the October issue of PLOS Genetics, which contained the first direct confirmation that both OCD and TS are highly heritable (or very inheritable). The report also discusses some major differences in the genetic makeup of the two conditions as well with OCD heritability being concentrated in specific chromosomes and TS heritability being spread among many different chromosomes.
According to one of the co-authors of the report, finding the exact genes responsible for TS is similar to trying to locate the proverbial needle in a haystack. This research attempted to narrow down where in this genetic haystack there might be needles. In doing so, this work demonstrated that the majority of genetic susceptibility to both TS and OCD can be discovered using what is called the GWAS or genome wide association study method.
The study confirmed that 20 percent of the genetic susceptibility of TS come from rare variants. In contrast, OCD derives all its susceptibility from common variants. That said, both TS and OCD have “shared genetic liability.” Additional investigations of these findings could help scientists to identify the affected genes and better understand how the expression changes contributes to someone having TS and OCD.
Further down the road, a greater understanding of the genetic origins of these conditions could contribute to the development of new therapeutic approaches. To read the full article, click here.