In general, Parkinson’s disease (PD) is a disease of older population. However, there are approximately 4% patients starting PD symptoms at age of 45 years or younger; and it is called early-onset Parkinson’s disease. PARK2 was identified as one of the causal factors of early-onset Parkinson’s disease that is under a recessive mode of inheritance .
PARK2 spans 1.36 Mb and comprises 12 small exons with a final processed transcript of 2.3 kb in size. Hence, the PARK2 gene is a typical example of extremely large genes encoding relatively small final processed transcripts. PARK2 is located within one of the most frequently expressed common fragile sites regions – FRA6E (6q26). Common fragile sites are large chromosomal regions of profound genomic instability that are hotspots for deletions and alterations especially within cancer cells . Gene-expression studies in cancer tissues and tumor-derived cell lines showed that there was reduced or absent PARK2 transcripts in all types of cancers including but not limited to ovarian cancer, breast cancer, renal cancer, lung cancer and colorectal cancer .