The British Journal of Psychiatry 150: 628-634 (1987)
© 1987 The Royal College of Psychiatrists
Tics and heredity. A study of the relatives of child tiqueurs
DM Zausmer and ME Dewey
Department of Psychiatry, University of Liverpool.
The limited literature on the pedigrees of tiqueurs, including those with
Gilles de la Tourette's syndrome, is reviewed. Most statistical analyses
have been restricted to affected family members without specifying the
unaffected ones. The present statistical analysis of a series of child
tiqueurs, including 91 probands and 1293 first- and second-degree
relatives, 46 of whom were tiqueurs, predicts the odds on being a tiqueur
for individuals, and establishes how those odds are affected by certain
explanatory variables using log-linear models. The data do not confirm a
familial pattern beyond reasonable doubt, but if the suggested prevalence
of tics in the population is 10% then the figure for parents is large
enough to support a familial hypothesis. The pedigrees do not indicate a
simple mode of genetic transmission. Further research is needed to confirm
that there is a connection between childhood tics and Gilles de la
Tourette's syndrome, to establish that the predisposition to tics is
familial, and, if so, whether there is a complex genetic mechanism
involved, or some other environmental aetiology so far undisclosed.
