Family history and Parkinson’s disease often get tied together in a way that feels absolute. If someone in the family has it, the fear is immediate. Does that mean it is inevitable?
This World Parkinson’s Day, that question comes up again. To make sense of it, India TV spoke to Dr Ramesh Menon, Director of Personal Genomics and Genomic Medicine at MedGenome. His explanation brings it back to something important. Risk is not the same as certainty.
Parkinson’s disease genetics: What family history means
For many people, the concern begins with a simple thought. If it runs in the family, it must be genetic.
But Dr Menon clarified that this link is often misunderstood. “Carrying Parkinson’s disease gene variants may raise a person’s risk, but it does not determine their future,” he explained.
That distinction matters. A lot. It shapes how families process both diagnosis and risk.
Parkinson’s disease genetics: How genes affect your risk
The role of genetics is real, but not always straightforward.
“About 30 percent of Parkinson’s cases can be traced to an identifiable genetic change,” Dr Menon said.
He explained that Parkinson’s genetics can be divided into two categories. “There are rare causal genetic variations in about 25 known risk genes, and around 2000 common genetic variations that together contribute to disease risk,” he noted.
“These are referred to as monogenic risk and polygenic risk,” the doctor added.
In monogenic cases, certain genes show stronger links. “Mutations in genes such as SNCA, LRRK2 and PINK1 are commonly seen in early onset Parkinson’s disease, typically before the age of 50,” Dr Menon said.
He also pointed out, “Mutations in the PRKN gene are more commonly associated with late onset disease.”
Parkinson’s disease types: Familial vs sporadic cases
Not every case with a genetic link comes from family history.
“About 10 to 15 percent of Parkinson’s disease cases are familial, where close blood relatives are affected and the genetic risk is inherited,” Dr Menon explained.
The majority, however, fall into a different category. “Most cases are sporadic, meaning there is no known family history,” he said.
Even in these cases, genetics still plays a role. “Rare and common genetic risk factors can still be detected, but carrying them does not mean the disease will necessarily develop,” the doctor clarified.
Parkinson’s disease risk factors: Role of environment
Genetics is only one part of the picture.
Dr Menon pointed out that patterns within families are not always purely genetic. “Clusters of Parkinson’s disease within families do not always reflect inherited genetics,” he explained.
Shared surroundings can create similar risks. “Living in the same environment, having similar occupations, and following comparable lifestyles can produce patterns that resemble hereditary disease,” he said.
He added that Parkinson’s is better understood as a mix of influences. “It emerges from the interaction of genetic predisposition, ageing, environmental exposures such as pesticides and industrial chemicals, and cellular processes,” Dr Menon said.
Parkinson’s disease in India: Why awareness and counselling matter
In India, the burden of neurological conditions continues to grow, but awareness around Parkinson’s genetics remains limited.
Dr Menon highlighted a common issue. “Families who receive a genetic finding often interpret it as a sentence rather than a probability,” he said.
That is where guidance becomes essential. “Genetic counselling is crucial before drawing conclusions from any test result,” the doctor explained.
A trained expert can put things into context. “A counsellor or neurologist can interpret the findings alongside a person’s clinical and family history, something raw data alone cannot do,” Dr Menon added.
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In the end, the takeaway stays simple. Risk is real, but it is not fixed. And understanding that difference can change how families deal with it.
Disclaimer: Tips and suggestions mentioned in the article are for general information purposes only and should not be construed as professional medical advice.
