Missense mutations and genomic multiplications of the alpha-synuclein gene (SNCA) have been linked to autosomal dominant familial Parkinson's disease. We screened 50 probands of families with autosomal dominant parkinsonism for alpha-synuclein mutations by exon sequencing. No known or novel mutations were found. We also analyzed the genomic DNA for multiplications of the SNCA locus using multiplex panels of microsatellite markers. All samples were diploid with two normal copies of the SNCA locus. Hence, alpha-synuclein missense mutations and SNCA genomic multiplications remain a rare cause of disease.