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 autosomal dominant PD (ADPD) in a family from Contursi, Italy, and three apparently unrelated Greek families. Several groups around the world failed to identify the G209A mutation in a sizable series of familial and sporadic cases of PD. The authors present two additional Greek families with ADPD associated with the G209A mutation. In both families, asymptomatic carriers older than the expected age at onset were found.