In five patients an alternative diagnosis was made: idiopathic late onset cerebellar ataxia (n = 1), functional tremor (n = 1), medication-induced parkinsonism (n = 1), (stable) unilateral resting tremor without evidence of dopamine deficit on dopamine transporter imaging (n = 1), and superficial hemosiderosis due to trombocytopenia (n = 1). This evidence concerns the gene SLC6A3 and Parkinson disease.