Absence of Mutation in the (3- and 7-Synuclein Genes in Familial Autosomal Dominant Parkinson's Disease

Parkinson's disease (PD) is a common progressive neu-rodegenerative disorder characterized by bradykinesia, muscular rigidity, resting tremor, and impaired postu-ral reflexes.1 Two missense mutations in the a-synuclein gene have been described in families with autosomal dom-inant Parkinson's disease: Ala53Thr in one Italian and three Greek families,2 and Ala30Pro in one family of German origin.3 These 2 mutations appear to account only for a minority of PD cases.2'3 Evidence of genetic heterogeneity4 indicates the necessity to evaluate other candidate genes for PD. Beta- and 7-synuclein are the two other members of the synuclein family.5 The a-, /?- and 7-synuclein proteins are well conserved across species, and have strong sequence homology between them.5 In particular, Ala30 of the a