Frequency of DYT1 mutation in early onset primary dystonia in Italian patients.

Thirty Italian patients with sporadic, early-onset, primary dystonia were screened for the DYT1 mutation. Five patients were positive (mean age at onset, 8 years); two had the typical phenotype, two a generalised dystonia also involving the cranial muscles, and one a segmental dystonia. In the other 25 patients (mean age at onset, 7.7 years), dystonia was generalised in 22 patients and remained segmental in three. Our results indicate the role of DYT1 mutation in Italian patients and confirm clinical and genetic heterogeneity of early-onset primary dystonia.