Understanding Parkinson’s disease in Asians and Caucasians
Over 30,000 participants across Asia were recruited to form the largest Parkinson’s disease study of its kind by a team of researchers from National Neuroscience Institute (NNI), Nanyang Technological University, Singapore (NTU Singapore)’s Lee Kong Chian School of Medicine, and Genome Institute of Singapore (GIS).
Apart from studying participants in Singapore, Malaysia, Hong Kong, Taiwan, mainland China, and South Korea, the team also collaborated with researchers in Europe, Japan, United Kingdom, and United States of America who collected samples from over one million participants. This collaboration allows the team to examine genetic samples of both Asian and Caucasian populations in relationto Parkinson’s disease.
Genetic risk factors identified for the first time
While the cause of Parkinson’s disease remains largely unknown, its symptoms are caused by the degeneration of a structure of the brain, causing a lack of a neurotransmitter called dopamine. Signs of Parkinson’s disease are common with normal aging and its symptoms include uncontrolled shaking of limbs, slow movements, stiff limbs and an unsteady walk.
The study, published in JAMA Neurology,identified two genetic risk factors that increased the likelihood of the disease among Asians and Caucasians. One risk factor was specific to the Asian population, while the other was present in both.
“We discovered two genes to be linked to Parkinson's disease that had never been identified before. Our findings will provide new insights into the biology underlying Parkinson’s disease,” Assistant Professor Foo Jia Nee, of NTU’s Lee Kong Chian School of Medicine and first author of the study, said.
The gene SV2C is associated with Parkinson's in both Asians and Caucasians, but more so in Asians. SV2C is found on the sacs of brain cells that produce dopamine. Removal of SV2C causes a reduction in the release of dopamine, which will affect motor functions in the individual. The other risk factor specific to Asians identified by the Singapore research team is the WBSCR17 gene.
Need for a genetic diagnostic kit
“The incidence of Parkinson’s disease and parkinsonism will increase as our population ages” says Professor Tan Eng King, Deputy Medical Director and Senior Consultant, Department of Neurology at NNI.
Three in 1000 adults above 50 years old suffers from Parkinson’s disease, making it one of the top neurological conditions in Singapore. Currently, there is no cure for Parkinson’s disease so patients rely on medications to help them control the symptoms of the progressive disease.
With these findings, researchers are now able to work towards developing a genetic diagnostic kit. Such kits will be able to identify those in the Asian population who are at risk of developing Parkinson’s disease. Hence,speeding up diagnosis and enabling early intervention.
This also could pave the way to development of drugs that could slow the progression of disease, thereby improving the quality of lives for people with the disease.