We have investigated the presence of mutations in the parkin gene in patients with early-onset parkinsonism. Direct sequencing of the polymerase chain reaction (PCR) products showed a homozygous G deletion in the exon 7 (c.871delG) in one patient. This was a 38-year-old Moroccan woman with a history of parkinsonism of 18 years of duration. The disease appeared as an apparently sporadic case and was characterized by dystonia of the legs at onset and a rapid progression to severe generalized parkinsonism but with an excellent maintained response to dopamine agonists treatment. The deletion was a frameshift mutation resulting in a stop codon at position 297 which causes truncation of the parkin protein. Mutations in the parkin gene can be encountered in patients with an apparently sporadic early-onset parkinsonism, rapidly progressive course and marked and maintained response to dopamine agonists.