Almost 12,000 people in Ireland have been diagnosed with Parkinson’s disease, a figure that is expected to double over the next 20 years. A paper from Massachusetts General Hospital may have found a link between the gene variant that produces red hair and fair skin in humans and in mice and Parkinson’s disease. Red hair and fair skin increase the danger of contracting the skin cancer melanoma, and there is already an established association between melanoma and Parkinson’s disease. In their paper, which appeared in this month’s issue of ‘Annals of Neurology’ having previously been published online, investigators report that the mice that carried the red hair variant of the melanocortin 1 receptor (MC1R) gene have lessened production of the neurotransmitter dopamine within the substantia nigra, the brain structure in which dopamine-producing neurons are destroyed in Parkinson’s disease (PD), thus making them more susceptible to toxins that are damaging to those neurons.
Lead of the report, Xiqun Chen, MD, PhD, of the MassGeneral Institute for Neurodegenerative Disease, claimed that, as MC1R regulates pigmentation, and red hair is a shared risk factor for both melanoma and Parkinson’s disease, it is possible that, in both conditions, MC1R’s role involves pigmentation and related oxidative stress. He told ‘ScienceDaily’ that this is the first study to display a direct influence of the melanoma-linked MC1R gene on dopaminergic neurons in the brain. He speculated that it could provide evidence for a novel Parkinson’s disease therapeutic strategy that targets MC1R.