PRKN and Onset: Deletions in the PARKIN gene (Chr6q26) are involved in about one-half of familial early-onset Parkinson's disease (PD) cases; as reviewed by Hedrich et al. [8] exons 3 and/or 4 (corresponding to the hotspot in 6q26) are deleted in 50% of cases, whereas exons 1 and 10, farthest from the hotspot we identify, contribute less than 2% to the total of exon deletion events.