Dr. Matthew State and colleagues at the Yale School of Medicine have published a research study in The New England Journal of Medicine, in which they discuss a defect in a gene called L-histidine decarboxylase or HDC. The researchers believe this defect is responsible for the development of TS in two generations of a particular family: a father and eight of his children. However, this gene defect was not found in hundreds of other families with TS, whose DNA was analyzed in the same study. Accordingly, it appears the HDC gene defect is a rare cause of TS.
Regardless, the discovery by Dr. State and colleagues could be a key development in our understanding of the brain changes that occur in TS patients. HDC is important for the production of histamine, which is well known for its role in allergies, but it is also present in the brain, where it is involved in communication between nerve cells. The HDC gene defect in the family with TS appears to interfere with the production and levels of histamine in certain parts of the brain. This finding raises the possibility that drugs that can alter the histamine systems in the brain might have a therapeutic benefit for TS. Thus, the study published by Dr. State and his colleagues could open new avenues of research and discovery.
The National TSA was instrumental in referring the noted family to Dr. State’s group. In addition to the Yale study authors, two members of the TSA’s International Consortium for Genetics (David Pauls, Ph.D., and Harvey Singer, M.D.) and a member of the TSA’s Medical Advisory Board (Donald Gilbert, M.D.) participated in the study.
We encourage all members of the TS community to assist researchers in their efforts to better understand and develop therapies for TS.
(Also reference this related WSJ report from earlier this month. A subscription may be required to read the entire article.)