Study finds key genetic variations associated with young onset of Parkinson’s disease in India

Parkinson’s disease is a progressive movement disorder affecting the nervous system, characterised by tremors, slow movement and difficulty in speaking.

Bengaluru: A first-of-its-kind study by genomics company MedGenome and the Parkinson's Research Alliance of India (PRAI) has found both common and rare genetic variations associated with Young Onset Parkinson's disease (YOPD) in the Indian population.

Parkinson’s disease is a progressive movement disorder affecting the nervous system, characterised by tremors, stiffness, slow movement, involuntary movements and difficulty in speaking, among other symptoms. Patients who develop Parkinson’s disease before the age of 40 or 50 years are said to have YOPD.

Dr Prashanth LK, principal investigator, PRAI, told DH that the paucity of data on Parkinson’s disease in India pushed researchers to conceptualise the study.

"Indian patients have a slightly younger age of onset of Parkinson’s disease as compared to western groups. If the average age of onset in the Western countries is 60 years, the onset is almost 10 years earlier in India,” he said. Patients with YOPD are more likely to have genetic forms of the disease, which became the focus of the study, he added.

The Genetics of PAN-India Young Onset Parkinson Disease (GOPI-YOPD) project recruited 1,000 patients across 10 speciality movement disorder centres or neurology clinics in the country. It aimed to identify genetic risk factors associated with YOPD in the Indian context, thus improving the understanding of the genetic basis of the disease.

The study has been published in the Movement Disorders Journal. A pilot study was published in the Advanced Biology Journal in July 2022.

Since Parkinson’s disease is not a single-gene disorder and people can present different gene mutations for the disease, researchers used a polygenic risk score (PRS) test, which can detect the likelihood of developing a disease due to one's genes, Dr Prashanth said.

"The gene mutations will decide what age you will develop the disease, what type of symptoms will develop prominently, their rate of progression, and how you will respond to different therapies,” he added.

Besides validating existing findings from the Western populations, the study also discovered a rare South Asia-specific mutation in the GBA gene, which is not seen in other populations.

Dr Vedam Ramprasad, CEO, MedGenome, said these findings would offer "systematic genetic evaluations" for the timely prevention and management of several diseases. This can help clinicians guide patients with early interventions and optimal treatment strategies.