Mutated alpha-synuclein gene in two Greek kindreds with familial PD: Incomplete penetrance?

The G209A mutation in the alpha-synuclein gene has been associated with aut osomal dominant PD (ADPD) in a family from Contursi, Italy, and three appar ently unrelated Greek families. Several groups around the world failed to i dentify the G209A mutation in a sizable series of familial and sporadic cas es of PD. The authors present two additional Greek families with ADPD assoc iated with the G209A mutation. In both families, asymptomatic carriers olde r than the expected age at onset were found.