Scientists have discovered a third gene' that leads to the development of the common neurodegenerative disease a study said. The study provided evidence that mutations in gene TMEM230 caused Parkinson's disease -- a disorder of the central nervous system that affects movement often including tremors. The study showed that mutations in this new gene lead to pathologically and clinically proven cases of the disease said led researcher Teepu Siddique Professor at Northwestern University in the US. The findings showed that the gene is responsible for producing a protein involved in packaging the neurotransmitter dopamine in neurons. Loss of dopamine-producing neurons