|
 |
|
|
|
|
|
|
|
|
|
The Tourette Syndrome Association has prepared a pamphlet on the genetics of Tourette Syndrome available through our online store. TSA continues to fund research in this vital area. The following is the text of a press release by TSA:
Search to Find Genetic Marker for Tourette Syndrome Takes a "Major Step Forward" With New Study Results
The world -wide search to find a genetic marker for Tourette Syndrome took a "major step forward" with the results of a study by the Tourette Syndrome Association Consortium for TS Genetics published in the November 1999 issue of the American Journal of Human Genetics (see summary below*).
David Pauls, Ph.D., a Population Geneticist, said that the Consortium's study discovered "two small pieces of the genome that may be strongly implicated with TS and four additional regions that may contribute" to Tourette Syndrome.
"This is the best information that we've ever had in terms of the actual location of a gene of genes for TS," Dr. Pauls said. "It is a major step forward."
The geneticist noted that all available evidence accrued over the last 30 years suggests that genetic factors are important for the expression of TS and that it is highly probable that several genes are involved. "This new data uncovered by our ten-center International Consortium strengthens that hypothesis and provides pointers to where these genes may be," he said.
The multi-site study, involved 76 families with two or more
children affected with TS...a total of 110 sibling pairs. Clinical information was taken as well as blood samples for DNA analysis. A panel of markers relatively evenly spaced across the genome were chosen. All of the markers were typed in all of the families to see whether there was an excess sharing of particular forms of markers by the affected siblings pairs. When there is a change in a particular region of TS-affected siblings that region is more likely to share markers that are close to an abnormal gene than those who are unaffected. Each of the markers has many different forms. If there is increased sharing of these different forms it suggests increasing susceptibility for TS.
"The next step," said Dr. Pauls, "is to get more data from more families to see whether these findings hold up. In the process our group will try to narrow the length of the region so that it is small enough to discover which gene is increasing the susceptibility for Tourette Syndrome."
*A Complete Genome Screen in Sib Pairs Affected by Gilles de la Tourette Syndrome, The Tourette Syndrome Association International Consortium for Genetics*
Am.J.Hum.Genet. 65:1428-1436, 1999
Summary
Gilles de la Tourette syndrome is a neuropsychiatric disorder characterized by waxing and waning multiple motor and phonictics with a complex mode of inheritance. Previous attempts, which used large multigenerational families to localize susceptibility loci, have been unsuccessful. In this report, the results of the first systemic genome scan, using 76 affected-sib-pair families with a total of 110 sib pairs, are summarized. While no results reached acceptable statistical significance, the multipoint maximum-likelihood scores (MLS) for two regions (4q and 8p) were suggestive (MLS > 2.0). Four additional genomic regions also gave multipoint MLS scores
between 1.0 and 2.0.
* The final manuscript was prepared by Drs. Sandkuijl and
Pauls with input from all members of the consortium. A
complete list of members can be found in the
Acknowledgments section at the end of the article.
The Tourette Syndrome continues to fund cutting-edge genetic research and invites your participation as a donor or participant through our sib-pair research program or brain-bank program. E-mail an expression of your interest to ts@tsa-usa.org, or telephone us at 718-224-2999.
©2007 Tourette Syndrome Association, Inc. 42-40 Bell Boulevard / Bayside NY 11361 / 718-224-2999