Pathogenic mutations in leucine-rich repeat kinase 2 (LRRK2; PARK8) have been implicated in autosomal dominant, late-onset Parkinson's disease (PD). The LRRK2 4321C>G (R1441G) mutation was originally identified in Spanish families originating from the Basque region. Within this ethnicity, Lrrk2 R1441G substitutions have been suggested as a frequent cause of disease. Herein we have assessed another referral-based series of 225 patients with PD from the neighboring region of Asturias, Northern Spain. The LRRK2 4321C>G mutation was found in 5 (2.7%) of sporadic, late-onset patients and was not present in control subjects. Although patients with a Lrrk2 R1441G substitution are apparently unrelated, they share a chromosome 12q12 haplotype not found in controls and indicative of a common founder.