Clinical phenotype in patients with alpha-synuclein Parkinson's disease living in Greece in comparison with patients with sporadic Parkinson's disease

Objective-An Ala53Thr mutation of the alpha -synuclein gene has been recent ly identified as a rare cause of autosomal Parkinson's disease (PD). The cl inical characteristics of 15 patients with PD living in Greece with the Ala 53Thr alpha -synuclein mutation (alpha -synPD) were compared with patients with sporadic Parkinson's disease (sPD). Methods-An investigator, blind to the results of the genetic analysis, exam ined 15 patients with alpha -synPD and 52 consecutive patients with sPD. De mographic data, age at onset of the illness, modality of presentation, and duration of PD were collected. The unified Parkinson's disease rating scale , the Hoehn and Yahr scale, and the Schwab-England scale were completed. Th e patients with alpha -synPD were matched ror duration of disease with 32 o f the 57 patients with sporadic PD (MsPD group). Results-Patients with the alpha -synuclein mutation were significantly youn ger (mean 7.6 years), showed the first sign of the disease significantly ea rlier ill life (mean 10.8 years), and had significantly longer duration of the disease compared with patients with sPD. Tremor at onset of the disease was present in only one (6.7%) of the patients with alpha -synPD, whereas it was present in 32 (61.5%) of the patients with sPD (p=0.0006). During th e course of the disease one patient in the alpha -synPD group went on to de velop tremor compared with six patients in the sPD group. Rigidity, bradyki nesia, postural instability orthostatic hypotension, intellectual impairmen t, depression complications of therapy, and clinical severity of the diseas e at the time of examination did not differ significantly between patients with alpha -synPD and these with sPD, or between patients with alpha -synPD and the MsPD group. Conclusion-The younger age at onset of the illness, the much lower prevalen ce of tremor. and tire longer duration of the disease characterise the clin ical phenotype in this sample of patients with alpha -synPD. The other symp toms and signs of the illness did not seem to differentiate the patients wi th alpha -synPD from those with sPD.