A twin study of Tourette syndrome.

  title={A twin study of Tourette syndrome.},
  author={Robert A. Price and Kenneth K. Kidd and Donald J. Cohen and David L. Pauls and James F. Leckman},
  journal={Archives of general psychiatry},
  volume={42 8},
In 43 pairs of same-sex twins, in which at least one co-twin had Tourette syndrome (TS), 30 pairs were probably monozygotic (MZ) and 13 were probably dizygotic (DZ). Concordances for TS were 53% and 8% for MZ and DZ pairs, respectively. When diagnostic criteria were broadened to include any tics in co-twins, concordance rates were 77% and 23% for MZ and DZ pairs, respectively. These concordances are consistent with genetic etiology. However, the fact that only 53% of MZ twins were fully… CONTINUE READING