Is PARKIN parkinsonism a cancer predisposition syndrome?

Mutations in the PARKIN gene (chromosome 6q25-27) were first described in 1998 in families with "juvenile" autosomal recessive parkinsonism. More than 180 causative variants in the PARKIN gene have been identified; point mutations and copy number variants (i.e., exon deletions or duplications) occur at nearly equal frequencies.(1) PARKIN is one of the largest genes in the human genome (1.3 Mb) and contains a chromosomal fragile site (CFS) FRA6E (6q26) between exons 2 and 8. This is of interest regarding the etiology of cancer because CFSs are prone to spontaneous breaks leading to chromosome alterations. Therefore, it is not surprising that PARKIN mutations have also been found in various cancer cell lines and primary tumors.(2,3) Mutations in PARKIN show decreased PARKIN E3 ligase function with resultant accumulation of cyclin E, creating the potential for mitotic instability in dividing cells.