We examined whether autosomal dominant parkinsonism of a Japanese family, Sagamihara family, was due to the mutations of alpha -synuclein, parkin, tau, and UCH-L?, which have been reported as the causal genes for parkinsonism in other families. Restriction-enzyme digestion of polymerase-chain reaction (PCR) amplified genomic DNA fragments of a-synuclein exons 3 and 4 detected no point mutation. PCR-amplification of parkin exons 3, 4, 5, 6 and 7 detected no exon deletion. Direct sequencing of PCR-amplified DNA fragments of tau exons 9, 10, 12, and 13 and intron 10, and of UCH-L1 exon 4 revealed that all these exons and intron were normal including a polymorphic nucleotide substitution. These results indicated that the parkinsonism of the Sagamihara family seems not to be due to previously identified point mutations of alpha -synuclein, tau, or UCH-L1, or to exon deletion of par kin. Copyright (C) 2001 S.Karger AG, Basel.