High frequency of Parkin exon rearrangements in Mexican-mestizo patients with early-onset Parkinson's disease

Background: Parkin mutations in patients with early-onset Parkinson's disease (EOPD) are estimated to occur in 49% of familial cases and 18% of sporadic cases. Methods: We analyzed the entire sequence-coding region and dosage mutations of parkin in 63 Mexican-mestizo EOPD patients and 120 controls. Results: Parkin mutations were present in 34 patients (54.0%). Exon rearrangements, predominantly spanning exons 9 and 12 (31.7% and 19.0%, respectively) were present in 32 patients, with 17.5% carrying simple heterozygous and 25.4% carrying compound heterozygous parkin mutations. Conclusions: A higher frequency of parkin exon rearrangements than of sequence mutations was observed. Patients with parkin exons 9 and 12 rearrangements showed a later age at onset than did cases with other regions affected (40.3 +/- 4.5 vs 30.1 +/- 8.8; P = .005), suggesting a mutational hot spot in the etiology of Mexican-mestizo patients with EOPD. To our knowledge, this study represents the largest sampling of Mexican-mestizo patients with EOPD cases for which parkin sequence and dosage alterations were analyzed. (c) 2012 Movement Disorder Society