Although a family history is described in approximately 20% of patients, la
rge families with adult-onset craniocervical primary (idiopathic) torsion d
ystonia (PTD) are rare. We report a new British family with cranio-cervical
dystonia. Seventeen members of the family were examined. Five cases were d
iagnosed as definite PTD and one as probable PTD. Mean age at onset was 29
years (range, 19-40 yrs). The phenotype was characterized by adult-onset cr
anio-cervical dystonia in all affected cases. A few cases had additional vo
ice tremor and/or postural arm tremor. The GAG deletion in the DYT1 gene wa
s excluded in the index case. Linkage analysis was performed between the di
sease and several marker loci spanning DYT6 and DYT7 regions, and haplotype
s were reconstructed in all subjects. Although linkage analysis was not com
pletely informative, reconstructed haplotypes excluded linkage between the
disease and either DYT6 or DYT7. This report confirms that familial cranio-
cervical dystonia is genetically heterogeneous, and further studies of othe
r PTD families with similar clinical features are needed to identify other
new genes.