An exciting new discovery on a genetic mutation that appears to be associated with Parkinson’s disease once again brings hope to some PD patients. The gene, known as VPS35, was identified in a large Swiss family with a history of Parkinson’s disease. While this may not be applicable for every case of Parkinson’s disease, it does open up possibilities about further understanding the genetic mechanisms related to certain cases where there is a strong family history of PD.
The study which appeared in the American Journal of Human Genetics (July 2011 issue) involved a global collaboration with researchers from the United States, United Kingdom, Canada, Europe and Asia. The research was led by Mayo Clinic neuroscientists and funded by several organizations, including in part by the Michael J. Fox Foundation.
The biochemical processes in Parkinson’s disease, particularly at the cellular level, is complex and not completely understood. The study has indicated that the VPS35 gene mutation disrupts the nerve cell’s (neurons) ability to recycle proteins facilitated by special protein complexes known as retromers. A faulty retromer therefore cannot play the integral role it usually does in this protein recycling process.
A new genetic sequencing technique was used to find the VPS35 mutation in first cousins of the large Swiss family with a strong history of Parkinson’s disease. By sequencing just the exome, the portion of the genome responsible for manufacturing proteins, the genetic mutation was discovered without the more costly and time consuming process of analyzing the entire genome. Exons constitute less than 2% of the human genome and exome sequencing allows scientist to identify genetic variations that causes changes in specific protein sequences.
This latest discovery adds to the five other genetic mutations already found to be associated with Parkinson’s disease. However, the VPS35 mutation discovery is not applicable to every case of PD and is more likely associated with late-onset Parkinson’s disease. Furthermore the mutation may not only be significant for Parkinson’s disease, as reduced gene expression was also seen with other neurodegenerative diseases like Alzheimer’s disease.
Clinical Significance of the VPS35 Discovery
The clinical significance of this discovery cannot as yet be fully appreciated but may go a long way in contributing to the development of specific drugs that can target the subsequent biochemical disruption associated with the VPS35 mutation. However, there is still a significant amount of research that has still has to be done surrounding this discovery and as one of the co-authors of the study, Own Ross (Ph.D.) stated, “… it appears to be a rare cause of Parkinson’s disease …”. Nevertheless, every discovery in the study of Parkinson’s disease holds new hope for all PD patients and contributes to a greater understanding of the disease as a whole.
As another co-author of the study, Zbigniew Wszolek (M.D.) , so accurately pointed out, “This finding provides an exciting new direction for Parkinson’ s disease research. Every new gene we discover for Parkinson’s disease opens up new ways to understand this complex disease, as well as potential ways of clinically managing it.”
- Mayo Researchers: Genetic Mutation Linked to Parkinson’s Disease. Mayo Clinic
- Parkinson’s Disease: Mutation In VPS35 Gene Linked To Late-Onset. Medical News Today